fix(settings): read PEM files but b64 env vars

- Extract base64 data from PEM files and secret files - Environment variables are not PEM encoded and only the base64 data - Affects OpenVPN certificate, key and encrypted key
2022-08-24 19:31:52 +00:00
316 changed files with 12694 additions and 46490 deletions
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,2 +1,2 @@
 FROM qmcgaw/godevcontainer
-RUN apk add wireguard-tools htop openssl
+RUN apk add wireguard-tools htop
--- a/.devcontainer/docker-compose.yml
+++ b/.devcontainer/docker-compose.yml
@@ -12,10 +12,10 @@ services:
      # Docker configuration
      - ~/.docker:/root/.docker
      # SSH directory for Linux, OSX and WSL
-      # On Linux and OSX, a symlink /mnt/ssh <-> ~/.ssh is
-      # created in the container. On Windows, files are copied
-      # from /mnt/ssh to ~/.ssh to fix permissions.
-      - ~/.ssh:/mnt/ssh
+      - ~/.ssh:/root/.ssh
+      # For Windows without WSL, a copy will be made
+      # from /tmp/.ssh to ~/.ssh to fix permissions
+      #- ~/.ssh:/tmp/.ssh:ro
      # Shell history persistence
      - ~/.zsh_history:/root/.zsh_history
      # Git config
--- a/.github/ISSUE_TEMPLATE/bug.yml
+++ b/.github/ISSUE_TEMPLATE/bug.yml
@@ -40,7 +40,6 @@ body:
    attributes:
      label: VPN service provider
      options:
-        - AirVPN
        - Custom
        - Cyberghost
        - ExpressVPN
@@ -55,10 +54,8 @@ body:
        - PrivateVPN
        - ProtonVPN
        - PureVPN
-        - SlickVPN
        - Surfshark
        - TorGuard
-        - VPNSecure.me
        - VPNUnlimited
        - VyprVPN
        - WeVPN
--- a/.github/labels.yml
+++ b/.github/labels.yml
@@ -1,13 +1,18 @@
-# Temporary status
- name: "🗯️ Waiting for feedback"
-  color: "aadefa"
+- name: "Bug :bug:"
+  color: "b60205"
+  description: ""
+- name: "Feature request :bulb:"
+  color: "0e8a16"
+  description: ""
+- name: "Help wanted :pray:"
+  color: "4caf50"
+  description: ""
+- name: "Documentation :memo:"
+  color: "c5def5"
+  description: ""
+- name: "Needs more info :thinking:"
+  color: "795548"
  description: ""
- name: "🔴 Blocked"
-  color: "ff3f14"
-  description: "Blocked by another issue or pull request"
- name: "🔒 After next release"
-  color: "e8f274"
-  description: "Will be done after the next release"

 # Priority
 - name: "🚨 Urgent"
@@ -17,18 +22,7 @@
  color: "4285f4"
  description: ""

-# Complexity
- name: "☣️ Hard to do"
-  color: "7d0008"
-  description: ""
- name: "🟩 Easy to do"
-  color: "34cf43"
-  description: ""
-
 # VPN providers
- name: ":cloud: AirVPN"
-  color: "cfe8d4"
-  description: ""
 - name: ":cloud: Cyberghost"
  color: "cfe8d4"
  description: ""
@@ -70,17 +64,12 @@
 - name: ":cloud: PureVPN"
  color: "cfe8d4"
  description: ""
- name: ":cloud: SlickVPN"
-  color: "cfe8d4"
-  description: ""
 - name: ":cloud: Surfshark"
  color: "cfe8d4"
  description: ""
 - name: ":cloud: Torguard"
  color: "cfe8d4"
  description: ""
- name: ":cloud: VPNSecure.me"
-  color: "cfe8d4"
 - name: ":cloud: VPNUnlimited"
  color: "cfe8d4"
  description: ""
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,15 +45,10 @@ jobs:
        with:
          locale: "US"
          level: error
-          exclude: |
-            ./internal/storage/servers.json

      - name: Linting
        run: docker build --target lint .

-      - name: Mocks check
-        run: docker build --target mocks .
-
      - name: Build test image
        run: docker build --target test -t test-container .

@@ -93,7 +88,6 @@ jobs:
    permissions:
      actions: read
      contents: read
-      packages: write
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
@@ -107,7 +101,6 @@ jobs:
          flavor: |
            latest=${{ github.ref == format('refs/heads/{0}', github.event.repository.default_branch) }}
          images: |
-            ghcr.io/qdm12/gluetun
            qmcgaw/gluetun
            qmcgaw/private-internet-access
          tags: |
@@ -125,18 +118,12 @@ jobs:
          username: qmcgaw
          password: ${{ secrets.DOCKERHUB_PASSWORD }}

-      - uses: docker/login-action@v2
-        with:
-          registry: ghcr.io
-          username: qdm12
-          password: ${{ github.token }}
-
      - name: Short commit
        id: shortcommit
        run: echo "::set-output name=value::$(git rev-parse --short HEAD)"

      - name: Build and push final image
-        uses: docker/build-push-action@v4.0.0
+        uses: docker/build-push-action@v3.0.0
        with:
          platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7,linux/ppc64le
          labels: ${{ steps.meta.outputs.labels }}
--- a/.github/workflows/labels.yml
+++ b/.github/workflows/labels.yml
@@ -7,8 +7,6 @@ on:
      - .github/workflows/labels.yml
 jobs:
  labeler:
-    permissions:
-      issues: write
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -19,6 +19,7 @@ issues:
      source: "^.+= os\\.OpenFile\\(.+, .+, 0[0-9]{3}\\)"
      linters:
        - gomnd
+
    - text: "^mnd: Magic number: 0[0-9]{3}, in <argument> detected$"
      source: "^.+= os\\.MkdirAll\\(.+, 0[0-9]{3}\\)"
      linters:
@@ -34,7 +35,8 @@ linters:
  enable:
    # - cyclop
    # - errorlint
-    - asasalint
+    # - varnamelen
+    # - wrapcheck
    - asciicheck
    - bidichk
    - bodyclose
@@ -65,8 +67,8 @@ linters:
    - goprintffuncname
    - gosec
    - grouper
+    - ifshort
    - importas
-    - interfacebloat
    - ireturn
    - lll
    - maintidx
@@ -81,8 +83,8 @@ linters:
    - nosprintfhostport
    - prealloc
    - predeclared
+    - predeclared
    - promlinter
-    - reassign
    - revive
    - rowserrcheck
    - sqlclosecheck
@@ -91,7 +93,6 @@ linters:
    - tparallel
    - unconvert
    - unparam
-    - usestdlibvars
    - wastedassign
    - whitespace

--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -5,11 +5,11 @@
            "name": "Update a VPN provider servers data",
            "type": "go",
            "request": "launch",
-            "cwd": "${workspaceFolder}",
+            "mode": "debug",
            "program": "cmd/gluetun/main.go",
            "args": [
                "update",
-                "${input:updateMode}",
+                "-enduser",
                "-providers",
                "${input:provider}"
            ],
@@ -20,16 +20,6 @@
            "id": "provider",
            "type": "promptString",
            "description": "Please enter a provider (or comma separated list of providers)",
-        },
-        {
-            "id": "updateMode",
-            "type": "pickString",
-            "description": "Update mode to use",
-            "options": [
-                "-maintainer",
-                "-enduser"
-            ],
-            "default": "-maintainer"
-        },
+        }
    ]
 }
--- a/40
+++ b/40
@@ -1,22 +1,18 @@
-ARG ALPINE_VERSION=3.17
-ARG GO_ALPINE_VERSION=3.17
-ARG GO_VERSION=1.20
+ARG ALPINE_VERSION=3.16
+ARG GO_ALPINE_VERSION=3.16
+ARG GO_VERSION=1.17
 ARG XCPUTRANSLATE_VERSION=v0.6.0
-ARG GOLANGCI_LINT_VERSION=v1.51.2
-ARG MOCKGEN_VERSION=v1.6.0
+ARG GOLANGCI_LINT_VERSION=v1.46.2
 ARG BUILDPLATFORM=linux/amd64

 FROM --platform=${BUILDPLATFORM} qmcgaw/xcputranslate:${XCPUTRANSLATE_VERSION} AS xcputranslate
 FROM --platform=${BUILDPLATFORM} qmcgaw/binpot:golangci-lint-${GOLANGCI_LINT_VERSION} AS golangci-lint
-FROM --platform=${BUILDPLATFORM} qmcgaw/binpot:mockgen-${MOCKGEN_VERSION} AS mockgen

 FROM --platform=${BUILDPLATFORM} golang:${GO_VERSION}-alpine${GO_ALPINE_VERSION} AS base
 COPY --from=xcputranslate /xcputranslate /usr/local/bin/xcputranslate
-# Note: findutils needed to have xargs support `-d` flag for mocks stage.
-RUN apk --update add git g++ findutils
+RUN apk --update add git g++
 ENV CGO_ENABLED=0
 COPY --from=golangci-lint /bin /go/bin/golangci-lint
-COPY --from=mockgen /bin /go/bin/mockgen
 WORKDIR /tmp/gobuild
 COPY go.mod go.sum ./
 RUN go mod download
@@ -34,18 +30,6 @@ FROM --platform=${BUILDPLATFORM} base AS lint
 COPY .golangci.yml ./
 RUN golangci-lint run --timeout=10m

-FROM --platform=${BUILDPLATFORM} base AS mocks
-RUN git init && \
-    git config user.email ci@localhost && \
-    git config user.name ci && \
-    git config core.fileMode false && \
-    git add -A && \
-    git commit -m "snapshot" && \
-    grep -lr -E '^// Code generated by MockGen\. DO NOT EDIT\.$' . | xargs -r -d '\n' rm && \
-    go generate -run "mockgen" ./... && \
-    git diff --exit-code && \
-    rm -rf .git/
-
 FROM --platform=${BUILDPLATFORM} base AS build
 ARG TARGETPLATFORM
 ARG VERSION=unknown
@@ -91,13 +75,13 @@ ENV VPN_SERVICE_PROVIDER=pia \
    OPENVPN_CIPHERS= \
    OPENVPN_AUTH= \
    OPENVPN_PROCESS_USER= \
+    OPENVPN_IPV6=off \
    OPENVPN_CUSTOM_CONFIG= \
    # Wireguard
    WIREGUARD_PRIVATE_KEY= \
    WIREGUARD_PRESHARED_KEY= \
    WIREGUARD_PUBLIC_KEY= \
    WIREGUARD_ADDRESSES= \
-    WIREGUARD_IMPLEMENTATION=auto \
    # VPN server filtering
    SERVER_REGIONS= \
    SERVER_COUNTRIES= \
@@ -111,15 +95,8 @@ ENV VPN_SERVICE_PROVIDER=pia \
    PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING=off \
    PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE="/tmp/gluetun/forwarded_port" \
    # # Cyberghost only:
-    OPENVPN_CERT= \
-    OPENVPN_KEY= \
    OPENVPN_CLIENTCRT_SECRETFILE=/run/secrets/openvpn_clientcrt \
    OPENVPN_CLIENTKEY_SECRETFILE=/run/secrets/openvpn_clientkey \
-    # # VPNSecure only:
-    OPENVPN_ENCRYPTED_KEY= \
-    OPENVPN_ENCRYPTED_KEY_SECRETFILE=/run/secrets/openvpn_encrypted_key \
-    OPENVPN_KEY_PASSPHRASE= \
-    OPENVPN_KEY_PASSPHRASE_SECRETFILE=/run/secrets/openvpn_key_passphrase \
    # # Nordvpn only:
    SERVER_NUMBER= \
    # # PIA only:
@@ -128,8 +105,6 @@ ENV VPN_SERVICE_PROVIDER=pia \
    FREE_ONLY= \
    # # Surfshark only:
    MULTIHOP_ONLY= \
-    # # VPN Secure only:
-    PREMIUM_ONLY= \
    # Firewall
    FIREWALL=on \
    FIREWALL_VPN_INPUT_PORTS= \
@@ -197,9 +172,8 @@ ENTRYPOINT ["/gluetun-entrypoint"]
 EXPOSE 8000/tcp 8888/tcp 8388/tcp 8388/udp
 HEALTHCHECK --interval=5s --timeout=5s --start-period=10s --retries=1 CMD /gluetun-entrypoint healthcheck
 ARG TARGETPLATFORM
-RUN apk add --no-cache --update -l wget && \
+RUN apk add --no-cache --update -l apk-tools && \
    apk add --no-cache --update -X "https://dl-cdn.alpinelinux.org/alpine/v3.12/main" openvpn==2.4.12-r0 && \
-    apk add --no-cache --update -X "https://dl-cdn.alpinelinux.org/alpine/v3.16/main" openssl\~1.1 && \
    mv /usr/sbin/openvpn /usr/sbin/openvpn2.4 && \
    apk del openvpn && \
    apk add --no-cache --update openvpn ca-certificates iptables ip6tables unbound tzdata && \
--- a/README.md
+++ b/README.md
@@ -1,130 +1,125 @@
-# Gluetun VPN client
-
-Lightweight swiss-knife-like VPN client to multiple VPN service providers
-
-![Title image](https://raw.githubusercontent.com/qdm12/gluetun/master/title.svg)
-
-[![Build status](https://github.com/qdm12/gluetun/actions/workflows/ci.yml/badge.svg)](https://github.com/qdm12/gluetun/actions/workflows/ci.yml)
-
-[![Docker pulls qmcgaw/gluetun](https://img.shields.io/docker/pulls/qmcgaw/gluetun.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
-[![Docker pulls qmcgaw/private-internet-access](https://img.shields.io/docker/pulls/qmcgaw/private-internet-access.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
-
-[![Docker stars qmcgaw/gluetun](https://img.shields.io/docker/stars/qmcgaw/gluetun.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
-[![Docker stars qmcgaw/private-internet-access](https://img.shields.io/docker/stars/qmcgaw/private-internet-access.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
-
-![Last release](https://img.shields.io/github/release/qdm12/gluetun?label=Last%20release)
-![Last Docker tag](https://img.shields.io/docker/v/qmcgaw/gluetun?sort=semver&label=Last%20Docker%20tag)
-[![Last release size](https://img.shields.io/docker/image-size/qmcgaw/gluetun?sort=semver&label=Last%20released%20image)](https://hub.docker.com/r/qmcgaw/gluetun/tags?page=1&ordering=last_updated)
-![GitHub last release date](https://img.shields.io/github/release-date/qdm12/gluetun?label=Last%20release%20date)
-![Commits since release](https://img.shields.io/github/commits-since/qdm12/gluetun/latest?sort=semver)
-
-[![Latest size](https://img.shields.io/docker/image-size/qmcgaw/gluetun/latest?label=Latest%20image)](https://hub.docker.com/r/qmcgaw/gluetun/tags)
-
-[![GitHub last commit](https://img.shields.io/github/last-commit/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/commits/master)
-[![GitHub commit activity](https://img.shields.io/github/commit-activity/y/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/graphs/contributors)
-[![GitHub closed PRs](https://img.shields.io/github/issues-pr-closed/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/pulls?q=is%3Apr+is%3Aclosed)
-[![GitHub issues](https://img.shields.io/github/issues/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/issues)
-[![GitHub closed issues](https://img.shields.io/github/issues-closed/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/issues?q=is%3Aissue+is%3Aclosed)
-
-[![Lines of code](https://img.shields.io/tokei/lines/github/qdm12/gluetun)](https://github.com/qdm12/gluetun)
-![Code size](https://img.shields.io/github/languages/code-size/qdm12/gluetun)
-![GitHub repo size](https://img.shields.io/github/repo-size/qdm12/gluetun)
-![Go version](https://img.shields.io/github/go-mod/go-version/qdm12/gluetun)
-
-![Visitors count](https://visitor-badge.laobi.icu/badge?page_id=gluetun.readme)
-
-## Quick links
-
- [Setup](#Setup)
- [Features](#Features)
- Problem?
-  - [Check the Wiki](https://github.com/qdm12/gluetun/wiki)
-  - [Start a discussion](https://github.com/qdm12/gluetun/discussions)
-  - [Fix the Unraid template](https://github.com/qdm12/gluetun/discussions/550)
- Suggestion?
-  - [Create an issue](https://github.com/qdm12/gluetun/issues)
-  - [Join the Slack channel](https://join.slack.com/t/qdm12/shared_invite/enQtOTE0NjcxNTM1ODc5LTYyZmVlOTM3MGI4ZWU0YmJkMjUxNmQ4ODQ2OTAwYzMxMTlhY2Q1MWQyOWUyNjc2ODliNjFjMDUxNWNmNzk5MDk)
- Happy?
-  - Sponsor me on [github.com/sponsors/qdm12](https://github.com/sponsors/qdm12)
-  - Donate to [paypal.me/qmcgaw](https://www.paypal.me/qmcgaw)
-  - Drop me [an email](mailto:quentin.mcgaw@gmail.com)
- **Want to add a VPN provider?** check [Development](https://github.com/qdm12/gluetun/wiki/Development) and [Add a provider](https://github.com/qdm12/gluetun/wiki/Add-a-provider)
- Video:
-
-  [![Video Gif](https://i.imgur.com/CetWunc.gif)](https://youtu.be/0F6I03LQcI4)
-
- [Substack Console interview](https://console.substack.com/p/console-72)
-
-## Features
-
- Based on Alpine 3.17 for a small Docker image of 42MB
- Supports: **AirVPN**, **Cyberghost**, **ExpressVPN**, **FastestVPN**, **HideMyAss**, **IPVanish**, **IVPN**, **Mullvad**, **NordVPN**, **Perfect Privacy**, **Privado**, **Private Internet Access**, **PrivateVPN**, **ProtonVPN**, **PureVPN**,  **SlickVPN**, **Surfshark**, **TorGuard**, **VPNSecure.me**, **VPNUnlimited**, **Vyprvpn**, **WeVPN**, **Windscribe** servers
- Supports OpenVPN for all providers listed
- Supports Wireguard both kernelspace and userspace
-  - For **Mullvad**, **Ivpn**, **Surfshark** and **Windscribe**
-  - For **ProtonVPN**, **PureVPN**, **Torguard**, **VPN Unlimited** and **WeVPN** using [the custom provider](https://github.com/qdm12/gluetun/wiki/Custom-provider)
-  - For custom Wireguard configurations using [the custom provider](https://github.com/qdm12/gluetun/wiki/Custom-provider)
-  - More in progress, see [#134](https://github.com/qdm12/gluetun/issues/134)
- DNS over TLS baked in with service provider(s) of your choice
- DNS fine blocking of malicious/ads/surveillance hostnames and IP addresses, with live update every 24 hours
- Choose the vpn network protocol, `udp` or `tcp`
- Built in firewall kill switch to allow traffic only with needed the VPN servers and LAN devices
- Built in Shadowsocks proxy (protocol based on SOCKS5 with an encryption layer, tunnels TCP+UDP)
- Built in HTTP proxy (tunnels HTTP and HTTPS through TCP)
- [Connect other containers to it](https://github.com/qdm12/gluetun/wiki/Connect-a-container-to-gluetun)
- [Connect LAN devices to it](https://github.com/qdm12/gluetun/wiki/Connect-a-LAN-device-to-gluetun)
- Compatible with amd64, i686 (32 bit), **ARM** 64 bit, ARM 32 bit v6 and v7, and even ppc64le 🎆
- [Custom VPN server side port forwarding for Private Internet Access](https://github.com/qdm12/gluetun/wiki/Private-internet-access#vpn-server-port-forwarding)
- Possibility of split horizon DNS by selecting multiple DNS over TLS providers
- Unbound subprogram drops root privileges once launched
- Can work as a Kubernetes sidecar container, thanks @rorph
-
-## Setup
-
-🎉 There are now instructions specific to each VPN provider with examples to help you get started as quickly as possible!
-
-Go to the [Wiki](https://github.com/qdm12/gluetun/wiki)!
-
-[🐛 Found a bug in the Wiki?!](https://github.com/qdm12/gluetun/issues/new?assignees=&labels=%F0%9F%93%84+Wiki+issue&template=wiki+issue.yml&title=Wiki+issue%3A+)
-
-Here's a docker-compose.yml for the laziest:
-
-```yml
-version: "3"
-services:
-  gluetun:
-    image: qmcgaw/gluetun
-    # container_name: gluetun
-    # line above must be uncommented to allow external containers to connect. See https://github.com/qdm12/gluetun/wiki/Connect-a-container-to-gluetun#external-container-to-gluetun
-    cap_add:
-      - NET_ADMIN
-    devices:
-      - /dev/net/tun:/dev/net/tun
-    ports:
-      - 8888:8888/tcp # HTTP proxy
-      - 8388:8388/tcp # Shadowsocks
-      - 8388:8388/udp # Shadowsocks
-    volumes:
-      - /yourpath:/gluetun
-    environment:
-      # See https://github.com/qdm12/gluetun/wiki
-      - VPN_SERVICE_PROVIDER=ivpn
-      - VPN_TYPE=openvpn
-      # OpenVPN:
-      - OPENVPN_USER=
-      - OPENVPN_PASSWORD=
-      # Wireguard:
-      # - WIREGUARD_PRIVATE_KEY=wOEI9rqqbDwnN8/Bpp22sVz48T71vJ4fYmFWujulwUU=
-      # - WIREGUARD_ADDRESSES=10.64.222.21/32
-      # Timezone for accurate log times
-      - TZ=
-      # Server list updater. See https://github.com/qdm12/gluetun/wiki/Updating-Servers#periodic-update
-      - UPDATER_PERIOD=
-      - UPDATER_VPN_SERVICE_PROVIDERS=
-```
-
-🆕 Image also available as `ghcr.io/qdm12/gluetun`
-
-## License
-
-[![MIT](https://img.shields.io/github/license/qdm12/gluetun)](https://github.com/qdm12/gluetun/master/LICENSE)
+# Gluetun VPN client
+
+Lightweight swiss-knife-like VPN client to multiple VPN sercice providers
+
+![Title image](https://raw.githubusercontent.com/qdm12/gluetun/master/title.svg)
+
+[![Build status](https://github.com/qdm12/gluetun/actions/workflows/ci.yml/badge.svg)](https://github.com/qdm12/gluetun/actions/workflows/ci.yml)
+
+[![Docker pulls qmcgaw/gluetun](https://img.shields.io/docker/pulls/qmcgaw/gluetun.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
+[![Docker pulls qmcgaw/private-internet-access](https://img.shields.io/docker/pulls/qmcgaw/private-internet-access.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
+
+[![Docker stars qmcgaw/gluetun](https://img.shields.io/docker/stars/qmcgaw/gluetun.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
+[![Docker stars qmcgaw/private-internet-access](https://img.shields.io/docker/stars/qmcgaw/private-internet-access.svg)](https://hub.docker.com/r/qmcgaw/gluetun)
+
+![Last release](https://img.shields.io/github/release/qdm12/gluetun?label=Last%20release)
+![Last Docker tag](https://img.shields.io/docker/v/qmcgaw/gluetun?sort=semver&label=Last%20Docker%20tag)
+[![Last release size](https://img.shields.io/docker/image-size/qmcgaw/gluetun?sort=semver&label=Last%20released%20image)](https://hub.docker.com/r/qmcgaw/gluetun/tags?page=1&ordering=last_updated)
+![GitHub last release date](https://img.shields.io/github/release-date/qdm12/gluetun?label=Last%20release%20date)
+![Commits since release](https://img.shields.io/github/commits-since/qdm12/gluetun/latest?sort=semver)
+
+[![Latest size](https://img.shields.io/docker/image-size/qmcgaw/gluetun/latest?label=Latest%20image)](https://hub.docker.com/r/qmcgaw/gluetun/tags)
+
+[![GitHub last commit](https://img.shields.io/github/last-commit/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/commits/master)
+[![GitHub commit activity](https://img.shields.io/github/commit-activity/y/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/graphs/contributors)
+[![GitHub closed PRs](https://img.shields.io/github/issues-pr-closed/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/pulls?q=is%3Apr+is%3Aclosed)
+[![GitHub issues](https://img.shields.io/github/issues/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/issues)
+[![GitHub closed issues](https://img.shields.io/github/issues-closed/qdm12/gluetun.svg)](https://github.com/qdm12/gluetun/issues?q=is%3Aissue+is%3Aclosed)
+
+[![Lines of code](https://img.shields.io/tokei/lines/github/qdm12/gluetun)](https://github.com/qdm12/gluetun)
+![Code size](https://img.shields.io/github/languages/code-size/qdm12/gluetun)
+![GitHub repo size](https://img.shields.io/github/repo-size/qdm12/gluetun)
+![Go version](https://img.shields.io/github/go-mod/go-version/qdm12/gluetun)
+
+![Visitors count](https://visitor-badge.laobi.icu/badge?page_id=gluetun.readme)
+
+## Quick links
+
+- [Setup](#Setup)
+- [Features](#Features)
+- Problem?
+  - [Check the Wiki](https://github.com/qdm12/gluetun/wiki)
+  - [Start a discussion](https://github.com/qdm12/gluetun/discussions)
+  - [Fix the Unraid template](https://github.com/qdm12/gluetun/discussions/550)
+- Suggestion?
+  - [Create an issue](https://github.com/qdm12/gluetun/issues)
+  - [Join the Slack channel](https://join.slack.com/t/qdm12/shared_invite/enQtOTE0NjcxNTM1ODc5LTYyZmVlOTM3MGI4ZWU0YmJkMjUxNmQ4ODQ2OTAwYzMxMTlhY2Q1MWQyOWUyNjc2ODliNjFjMDUxNWNmNzk5MDk)
+- Happy?
+  - Sponsor me on [github.com/sponsors/qdm12](https://github.com/sponsors/qdm12)
+  - Donate to [paypal.me/qmcgaw](https://www.paypal.me/qmcgaw)
+  - Drop me [an email](mailto:quentin.mcgaw@gmail.com)
+- **Want to add a VPN provider?** check [Development](https://github.com/qdm12/gluetun/wiki/Development) and [Add a provider](https://github.com/qdm12/gluetun/wiki/Add-a-provider)
+- Video:
+
+  [![Video Gif](https://i.imgur.com/CetWunc.gif)](https://youtu.be/0F6I03LQcI4)
+
+- [Substack Console interview](https://console.substack.com/p/console-72)
+
+## Features
+
+- Based on Alpine 3.16 for a small Docker image of 29MB
+- Supports: **Cyberghost**, **ExpressVPN**, **FastestVPN**, **HideMyAss**, **IPVanish**, **IVPN**, **Mullvad**, **NordVPN**, **Perfect Privacy**, **Privado**, **Private Internet Access**, **PrivateVPN**, **ProtonVPN**, **PureVPN**,  **Surfshark**, **TorGuard**, **VPNUnlimited**, **Vyprvpn**, **WeVPN**, **Windscribe** servers
+- Supports OpenVPN for all providers listed
+- Supports Wireguard both kernelspace and userspace
+  - For **Mullvad**, **Ivpn** and **Windscribe**
+  - For **Torguard**, **VPN Unlimited** and **WeVPN** using [the custom provider](https://github.com/qdm12/gluetun/wiki/Custom-provider)
+  - For custom Wireguard configurations using [the custom provider](https://github.com/qdm12/gluetun/wiki/Custom-provider)
+  - More in progress, see [#134](https://github.com/qdm12/gluetun/issues/134)
+- DNS over TLS baked in with service provider(s) of your choice
+- DNS fine blocking of malicious/ads/surveillance hostnames and IP addresses, with live update every 24 hours
+- Choose the vpn network protocol, `udp` or `tcp`
+- Built in firewall kill switch to allow traffic only with needed the VPN servers and LAN devices
+- Built in Shadowsocks proxy (protocol based on SOCKS5 with an encryption layer, tunnels TCP+UDP)
+- Built in HTTP proxy (tunnels HTTP and HTTPS through TCP)
+- [Connect other containers to it](https://github.com/qdm12/gluetun/wiki/Connect-a-container-to-gluetun)
+- [Connect LAN devices to it](https://github.com/qdm12/gluetun/wiki/Connect-a-LAN-device-to-gluetun)
+- Compatible with amd64, i686 (32 bit), **ARM** 64 bit, ARM 32 bit v6 and v7, and even ppc64le 🎆
+- [Custom VPN server side port forwarding for Private Internet Access](https://github.com/qdm12/gluetun/wiki/Private-internet-access#vpn-server-port-forwarding)
+- Possibility of split horizon DNS by selecting multiple DNS over TLS providers
+- Unbound subprogram drops root privileges once launched
+- Can work as a Kubernetes sidecar container, thanks @rorph
+
+## Setup
+
+🎉 There are now instructions specific to each VPN provider with examples to help you get started as quickly as possible!
+
+Go to the [Wiki](https://github.com/qdm12/gluetun/wiki)!
+
+[🐛 Found a bug in the Wiki?!](https://github.com/qdm12/gluetun/issues/new?assignees=&labels=%F0%9F%93%84+Wiki+issue&template=wiki+issue.yml&title=Wiki+issue%3A+)
+
+Here's a docker-compose.yml for the laziest:
+
+```yml
+version: "3"
+services:
+  gluetun:
+    image: qmcgaw/gluetun
+    # container_name: gluetun
+    # line above must be uncommented to allow external containers to connect. See https://github.com/qdm12/gluetun/wiki/Connect-a-container-to-gluetun#external-container-to-gluetun
+    cap_add:
+      - NET_ADMIN
+    devices:
+      - /dev/net/tun:/dev/net/tun
+    ports:
+      - 8888:8888/tcp # HTTP proxy
+      - 8388:8388/tcp # Shadowsocks
+      - 8388:8388/udp # Shadowsocks
+    volumes:
+      - /yourpath:/gluetun
+    environment:
+      # See https://github.com/qdm12/gluetun/wiki
+      - VPN_SERVICE_PROVIDER=ivpn
+      - VPN_TYPE=openvpn
+      # OpenVPN:
+      - OPENVPN_USER=
+      - OPENVPN_PASSWORD=
+      # Wireguard:
+      # - WIREGUARD_PRIVATE_KEY=wOEI9rqqbDwnN8/Bpp22sVz48T71vJ4fYmFWujulwUU=
+      # - WIREGUARD_ADDRESSES=10.64.222.21/32
+      # Timezone for accurate log times
+      - TZ=
+```
+
+## License
+
+[![MIT](https://img.shields.io/github/license/qdm12/gluetun)](https://github.com/qdm12/gluetun/master/LICENSE)
--- a/cmd/gluetun/main.go
+++ b/cmd/gluetun/main.go
@@ -16,10 +16,10 @@ import (
 	"github.com/qdm12/dns/pkg/unbound"
 	"github.com/qdm12/gluetun/internal/alpine"
 	"github.com/qdm12/gluetun/internal/cli"
-	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/configuration/sources"
 	"github.com/qdm12/gluetun/internal/configuration/sources/env"
 	"github.com/qdm12/gluetun/internal/configuration/sources/files"
-	mux "github.com/qdm12/gluetun/internal/configuration/sources/merge"
+	"github.com/qdm12/gluetun/internal/configuration/sources/mux"
 	"github.com/qdm12/gluetun/internal/configuration/sources/secrets"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/dns"
@@ -77,8 +77,7 @@ func main() {

 	args := os.Args
 	tun := tun.New()
-	netLinkDebugLogger := logger.New(log.SetComponent("netlink"))
-	netLinker := netlink.New(netLinkDebugLogger)
+	netLinker := netlink.New()
 	cli := cli.New()
 	cmder := command.NewCmder()

@@ -92,13 +91,12 @@ func main() {
 		errorCh <- _main(ctx, buildInfo, args, logger, muxReader, tun, netLinker, cmder, cli)
 	}()

-	var err error
 	select {
 	case signal := <-signalCh:
 		fmt.Println("")
 		logger.Warn("Caught OS signal " + signal.String() + ", shutting down")
 		cancel()
-	case err = <-errorCh:
+	case err := <-errorCh:
 		close(errorCh)
 		if err == nil { // expected exit such as healthcheck
 			os.Exit(0)
@@ -110,27 +108,18 @@ func main() {
 	const shutdownGracePeriod = 5 * time.Second
 	timer := time.NewTimer(shutdownGracePeriod)
 	select {
-	case shutdownErr := <-errorCh:
+	case <-errorCh:
 		if !timer.Stop() {
 			<-timer.C
 		}
-		if shutdownErr != nil {
-			logger.Warnf("Shutdown not completed gracefully: %s", shutdownErr)
-			os.Exit(1)
-		}
-
 		logger.Info("Shutdown successful")
-		if err != nil {
-			os.Exit(1)
-		}
-		os.Exit(0)
 	case <-timer.C:
 		logger.Warn("Shutdown timed out")
-		os.Exit(1)
 	case signal := <-signalCh:
 		logger.Warn("Caught OS signal " + signal.String() + ", forcing shut down")
-		os.Exit(1)
 	}
+
+	os.Exit(1)
 }

 var (
@@ -139,7 +128,7 @@ var (

 //nolint:gocognit,gocyclo,maintidx
 func _main(ctx context.Context, buildInfo models.BuildInformation,
-	args []string, logger log.LoggerInterface, source Source,
+	args []string, logger log.LoggerInterface, source sources.Source,
 	tun Tun, netLinker netLinker, cmder command.RunStarter,
 	cli clier) error {
 	if len(args) > 1 { // cli operation
@@ -149,7 +138,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		case "clientkey":
 			return cli.ClientKey(args[2:])
 		case "openvpnconfig":
-			return cli.OpenvpnConfig(logger, source, netLinker)
+			return cli.OpenvpnConfig(logger, source)
 		case "update":
 			return cli.Update(ctx, args[2:], logger)
 		case "format-servers":
@@ -190,7 +179,6 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	// - firewall Debug and Enabled are booleans parsed from source

 	logger.Patch(log.SetLevel(*allSettings.Log.Level))
-	netLinker.PatchLoggerLevel(*allSettings.Log.Level)

 	routingLogger := logger.New(log.SetComponent("routing"))
 	if *allSettings.Firewall.Debug { // To remove in v4
@@ -232,12 +220,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		return err
 	}

-	ipv6Supported, err := netLinker.IsIPv6Supported()
-	if err != nil {
-		return fmt.Errorf("checking for IPv6 support: %w", err)
-	}
-
-	err = allSettings.Validate(storage, ipv6Supported)
+	err = allSettings.Validate(storage)
 	if err != nil {
 		return err
 	}
@@ -245,7 +228,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	allSettings.Pprof.HTTPServer.Logger = logger.New(log.SetComponent("pprof"))
 	pprofServer, err := pprof.New(allSettings.Pprof)
 	if err != nil {
-		return fmt.Errorf("creating Pprof server: %w", err)
+		return fmt.Errorf("cannot create Pprof server: %w", err)
 	}

 	puid, pgid := int(*allSettings.System.PUID), int(*allSettings.System.PGID)
@@ -277,10 +260,6 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,

 	logger.Info(allSettings.String())

-	for _, warning := range allSettings.Warnings() {
-		logger.Warn(warning)
-	}
-
 	if err := os.MkdirAll("/tmp/gluetun", 0644); err != nil {
 		return err
 	}
@@ -291,7 +270,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	const defaultUsername = "nonrootuser"
 	nonRootUsername, err := alpineConf.CreateUser(defaultUsername, puid)
 	if err != nil {
-		return fmt.Errorf("creating user: %w", err)
+		return fmt.Errorf("cannot create user: %w", err)
 	}
 	if nonRootUsername != defaultUsername {
 		logger.Info("using existing username " + nonRootUsername + " corresponding to user id " + fmt.Sprint(puid))
@@ -309,7 +288,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		if strings.Contains(err.Error(), "operation not permitted") {
 			logger.Warn("💡 Tip: Are you passing NET_ADMIN capability to gluetun?")
 		}
-		return fmt.Errorf("setting up routing: %w", err)
+		return fmt.Errorf("cannot setup routing: %w", err)
 	}
 	defer func() {
 		routingLogger.Info("routing cleanup...")
@@ -360,14 +339,11 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	tickersGroupHandler := goshutdown.NewGroupHandler("tickers", defaultGroupOptions...)
 	otherGroupHandler := goshutdown.NewGroupHandler("other", defaultGroupOptions...)

-	if *allSettings.Pprof.Enabled {
-		// TODO run in run loop so this can be patched at runtime
-		pprofReady := make(chan struct{})
-		pprofHandler, pprofCtx, pprofDone := goshutdown.NewGoRoutineHandler("pprof server")
-		go pprofServer.Run(pprofCtx, pprofReady, pprofDone)
-		otherGroupHandler.Add(pprofHandler)
-		<-pprofReady
-	}
+	pprofReady := make(chan struct{})
+	pprofHandler, pprofCtx, pprofDone := goshutdown.NewGoRoutineHandler("pprof server")
+	go pprofServer.Run(pprofCtx, pprofReady, pprofDone)
+	otherGroupHandler.Add(pprofHandler)
+	<-pprofReady

 	portForwardLogger := logger.New(log.SetComponent("port forwarding"))
 	portForwardLooper := portforward.NewLoop(allSettings.VPN.Provider.PortForwarding,
@@ -413,7 +389,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		httpClient, unzipper, parallelResolver, ipFetcher, openvpnFileExtractor)

 	vpnLogger := logger.New(log.SetComponent("vpn"))
-	vpnLooper := vpn.NewLoop(allSettings.VPN, ipv6Supported, allSettings.Firewall.VPNInputPorts,
+	vpnLooper := vpn.NewLoop(allSettings.VPN, allSettings.Firewall.VPNInputPorts,
 		providers, storage, ovpnConf, netLinker, firewallConf, routingConf, portForwardLooper,
 		cmder, publicIPLooper, unboundLooper, vpnLogger, httpClient,
 		buildInfo, *allSettings.Version.Enabled)
@@ -455,10 +431,9 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		"http server", goroutine.OptionTimeout(defaultShutdownTimeout))
 	httpServer, err := server.New(httpServerCtx, controlServerAddress, controlServerLogging,
 		logger.New(log.SetComponent("http server")),
-		buildInfo, vpnLooper, portForwardLooper, unboundLooper, updaterLooper, publicIPLooper,
-		storage, ipv6Supported)
+		buildInfo, vpnLooper, portForwardLooper, unboundLooper, updaterLooper, publicIPLooper)
 	if err != nil {
-		return fmt.Errorf("setting up control server: %w", err)
+		return fmt.Errorf("cannot setup control server: %w", err)
 	}
 	httpServerReady := make(chan struct{})
 	go httpServer.Run(httpServerCtx, httpServerReady, httpServerDone)
@@ -505,7 +480,7 @@ func printVersions(ctx context.Context, logger infoer,
 	for _, element := range elements {
 		version, err := element.getVersion(ctx)
 		if err != nil {
-			return fmt.Errorf("getting %s version: %w", element.name, err)
+			return err
 		}
 		logger.Info(element.name + " version: " + version)
 	}
@@ -514,36 +489,18 @@ func printVersions(ctx context.Context, logger infoer,
 }

 type netLinker interface {
-	Addresser
-	Router
-	Ruler
-	Linker
-	IsWireguardSupported() (ok bool, err error)
-	IsIPv6Supported() (ok bool, err error)
-	PatchLoggerLevel(level log.Level)
-}
-
-type Addresser interface {
 	AddrList(link netlink.Link, family int) (
 		addresses []netlink.Addr, err error)
 	AddrAdd(link netlink.Link, addr *netlink.Addr) error
-}
-
-type Router interface {
+	IsWireguardSupported() (ok bool, err error)
 	RouteList(link netlink.Link, family int) (
 		routes []netlink.Route, err error)
 	RouteAdd(route *netlink.Route) error
 	RouteDel(route *netlink.Route) error
 	RouteReplace(route *netlink.Route) error
-}
-
-type Ruler interface {
 	RuleList(family int) (rules []netlink.Rule, err error)
 	RuleAdd(rule *netlink.Rule) error
 	RuleDel(rule *netlink.Rule) error
-}
-
-type Linker interface {
 	LinkList() (links []netlink.Link, err error)
 	LinkByName(name string) (link netlink.Link, err error)
 	LinkByIndex(index int) (link netlink.Link, err error)
@@ -556,8 +513,8 @@ type Linker interface {
 type clier interface {
 	ClientKey(args []string) error
 	FormatServers(args []string) error
-	OpenvpnConfig(logger cli.OpenvpnConfigLogger, source cli.Source, ipv6Checker cli.IPv6Checker) error
-	HealthCheck(ctx context.Context, source cli.Source, warner cli.Warner) error
+	OpenvpnConfig(logger cli.OpenvpnConfigLogger, source sources.Source) error
+	HealthCheck(ctx context.Context, source sources.Source, warner cli.Warner) error
 	Update(ctx context.Context, args []string, logger cli.UpdaterLogger) error
 }

@@ -565,9 +522,3 @@ type Tun interface {
 	Check(tunDevice string) error
 	Create(tunDevice string) error
 }
-
-type Source interface {
-	Read() (settings settings.Settings, err error)
-	ReadHealth() (health settings.Health, err error)
-	String() string
-}
--- a/go.mod
+++ b/go.mod
@@ -1,10 +1,10 @@
 module github.com/qdm12/gluetun

-go 1.20
+go 1.17

 require (
-	github.com/breml/rootcerts v0.2.10
-	github.com/fatih/color v1.14.1
+	github.com/breml/rootcerts v0.2.3
+	github.com/fatih/color v1.13.0
 	github.com/golang/mock v1.6.0
 	github.com/qdm12/dns v1.11.0
 	github.com/qdm12/golibs v0.0.0-20210822203818-5c568b0777b6
@@ -15,35 +15,31 @@ require (
 	github.com/qdm12/log v0.1.0
 	github.com/qdm12/ss-server v0.4.0
 	github.com/qdm12/updated v0.0.0-20210603204757-205acfe6937e
-	github.com/stretchr/testify v1.8.2
+	github.com/stretchr/testify v1.7.2
 	github.com/vishvananda/netlink v1.1.1-0.20211129163951-9ada19101fc5
-	github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a
-	golang.org/x/net v0.0.0-20220418201149-a630d4f3e7a2
-	golang.org/x/sys v0.6.0
-	golang.org/x/text v0.8.0
-	golang.zx2c4.com/wireguard v0.0.0-20220703234212-c31a7b1ab478
-	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20220504211119-3d4a969bb56b
+	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
+	golang.org/x/text v0.3.7
+	golang.zx2c4.com/wireguard v0.0.0-20210805125648-3957e9b9dd19
+	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20210803171230-4253848d036c
 	inet.af/netaddr v0.0.0-20210718074554-06ca8145d722
 )

 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/google/go-cmp v0.5.7 // indirect
-	github.com/josharian/native v1.0.0 // indirect
-	github.com/mattn/go-colorable v0.1.13 // indirect
-	github.com/mattn/go-isatty v0.0.17 // indirect
-	github.com/mdlayher/genetlink v1.2.0 // indirect
-	github.com/mdlayher/netlink v1.6.0 // indirect
-	github.com/mdlayher/socket v0.2.3 // indirect
+	github.com/google/go-cmp v0.5.5 // indirect
+	github.com/josharian/native v0.0.0-20200817173448-b6b71def0850 // indirect
+	github.com/mattn/go-colorable v0.1.9 // indirect
+	github.com/mattn/go-isatty v0.0.14 // indirect
+	github.com/mdlayher/genetlink v1.0.0 // indirect
+	github.com/mdlayher/netlink v1.4.0 // indirect
 	github.com/miekg/dns v1.1.40 // indirect
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3 // indirect
 	github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae // indirect
 	go4.org/intern v0.0.0-20210108033219-3eb7198706b2 // indirect
-	go4.org/unsafe/assume-no-moving-gc v0.0.0-20230221090011-e4bae7ad2296 // indirect
-	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4 // indirect
-	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
-	golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224 // indirect
+	go4.org/unsafe/assume-no-moving-gc v0.0.0-20220617031537-928513b29760 // indirect
+	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
+	golang.org/x/net v0.0.0-20210504132125-bbd867fde50d // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
--- a/go.sum
+++ b/go.sum
@@ -4,8 +4,8 @@ github.com/alcortesm/tgz v0.0.0-20161220082320-9c5fe88206d7/go.mod h1:6zEj6s6u/g
 github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYUyUczH0OGQWaF5ceTx0UBShxjsH6f8oGKYe2c=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
 github.com/asaskevich/govalidator v0.0.0-20180720115003-f9ffefc3facf/go.mod h1:lB+ZfQJz7igIIfQNfa7Ml4HSf2uFQQRzpGGRXenZAgY=
-github.com/breml/rootcerts v0.2.10 h1:UGVZ193UTSUASpGtg6pbDwzOd7XQP+at0Ssg1/2E4h8=
-github.com/breml/rootcerts v0.2.10/go.mod h1:24FDtzYMpqIeYC7QzaE8VPRQaFZU5TIUDlyk8qwjD88=
+github.com/breml/rootcerts v0.2.3 h1:1vkYjKOiHVSyuz9Ue4AOrViEvUm8gk8phTg0vbcuU0A=
+github.com/breml/rootcerts v0.2.3/go.mod h1:24FDtzYMpqIeYC7QzaE8VPRQaFZU5TIUDlyk8qwjD88=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
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@@ -14,8 +14,8 @@ github.com/docker/go-units v0.3.3/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDD
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+golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.8.0 h1:57P1ETyNKtuIjB4SRd15iJxuhj8Gc416Y78H3qgMh68=
-golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
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@@ -205,12 +237,11 @@ golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224 h1:Ug9qvr1myri/zFN6xL17LSCBGFDnphBBhzmILHsM5TY=
-golang.zx2c4.com/wintun v0.0.0-20211104114900-415007cec224/go.mod h1:deeaetjYA+DHMHg+sMSMI58GrEteJUUzzw7en6TJQcI=
-golang.zx2c4.com/wireguard v0.0.0-20220703234212-c31a7b1ab478 h1:vDy//hdR+GnROE3OdYbQKt9rdtNdHkDtONvpRwmls/0=
-golang.zx2c4.com/wireguard v0.0.0-20220703234212-c31a7b1ab478/go.mod h1:bVQfyl2sCM/QIIGHpWbFGfHPuDvqnCNkT6MQLTCjO/U=
-golang.zx2c4.com/wireguard/wgctrl v0.0.0-20220504211119-3d4a969bb56b h1:9JncmKXcUwE918my+H6xmjBdhK2jM/UTUNXxhRG1BAk=
-golang.zx2c4.com/wireguard/wgctrl v0.0.0-20220504211119-3d4a969bb56b/go.mod h1:yp4gl6zOlnDGOZeWeDfMwQcsdOIQnMdhuPx9mwwWBL4=
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 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
--- a/internal/cli/formatservers.go
+++ b/internal/cli/formatservers.go
@@ -73,7 +73,7 @@ func (c *CLI) FormatServers(args []string) error {
 	logger := newNoopLogger()
 	storage, err := storage.New(logger, constants.ServersData)
 	if err != nil {
-		return fmt.Errorf("creating servers storage: %w", err)
+		return fmt.Errorf("cannot create servers storage: %w", err)
 	}

 	formatted := storage.FormatToMarkdown(providerToFormat)
@@ -81,18 +81,18 @@ func (c *CLI) FormatServers(args []string) error {
 	output = filepath.Clean(output)
 	file, err := os.OpenFile(output, os.O_TRUNC|os.O_WRONLY|os.O_CREATE, 0644)
 	if err != nil {
-		return fmt.Errorf("opening output file: %w", err)
+		return fmt.Errorf("cannot open output file: %w", err)
 	}

 	_, err = fmt.Fprint(file, formatted)
 	if err != nil {
 		_ = file.Close()
-		return fmt.Errorf("writing to output file: %w", err)
+		return fmt.Errorf("cannot write to output file: %w", err)
 	}

 	err = file.Close()
 	if err != nil {
-		return fmt.Errorf("closing output file: %w", err)
+		return fmt.Errorf("cannot close output file: %w", err)
 	}

 	return nil
--- a/internal/cli/healthcheck.go
+++ b/internal/cli/healthcheck.go
@@ -6,18 +6,17 @@ import (
 	"net/http"
 	"time"

+	"github.com/qdm12/gluetun/internal/configuration/sources"
 	"github.com/qdm12/gluetun/internal/healthcheck"
 )

-func (c *CLI) HealthCheck(ctx context.Context, source Source, warner Warner) error {
+func (c *CLI) HealthCheck(ctx context.Context, source sources.Source, warner Warner) error {
 	// Extract the health server port from the configuration.
 	config, err := source.ReadHealth()
 	if err != nil {
 		return err
 	}

-	config.SetDefaults()
-
 	err = config.Validate()
 	if err != nil {
 		return err
--- a/internal/cli/openvpnconfig.go
+++ b/internal/cli/openvpnconfig.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"

+	"github.com/qdm12/gluetun/internal/configuration/sources"
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/openvpn/extract"
 	"github.com/qdm12/gluetun/internal/provider"
@@ -35,12 +36,7 @@ type IPFetcher interface {
 	FetchMultiInfo(ctx context.Context, ips []net.IP) (data []ipinfo.Response, err error)
 }

-type IPv6Checker interface {
-	IsIPv6Supported() (supported bool, err error)
-}
-
-func (c *CLI) OpenvpnConfig(logger OpenvpnConfigLogger, source Source,
-	ipv6Checker IPv6Checker) error {
+func (c *CLI) OpenvpnConfig(logger OpenvpnConfigLogger, source sources.Source) error {
 	storage, err := storage.New(logger, constants.ServersData)
 	if err != nil {
 		return err
@@ -51,13 +47,8 @@ func (c *CLI) OpenvpnConfig(logger OpenvpnConfigLogger, source Source,
 		return err
 	}

-	ipv6Supported, err := ipv6Checker.IsIPv6Supported()
-	if err != nil {
-		return fmt.Errorf("checking for IPv6 support: %w", err)
-	}
-
-	if err = allSettings.Validate(storage, ipv6Supported); err != nil {
-		return fmt.Errorf("validating settings: %w", err)
+	if err = allSettings.Validate(storage); err != nil {
+		return err
 	}

 	// Unused by this CLI command
@@ -71,14 +62,12 @@ func (c *CLI) OpenvpnConfig(logger OpenvpnConfigLogger, source Source,
 	providers := provider.NewProviders(storage, time.Now, warner, client,
 		unzipper, parallelResolver, ipFetcher, openvpnFileExtractor)
 	providerConf := providers.Get(*allSettings.VPN.Provider.Name)
-	connection, err := providerConf.GetConnection(
-		allSettings.VPN.Provider.ServerSelection, ipv6Supported)
+	connection, err := providerConf.GetConnection(allSettings.VPN.Provider.ServerSelection)
 	if err != nil {
 		return err
 	}

-	lines := providerConf.OpenVPNConfig(connection,
-		allSettings.VPN.OpenVPN, ipv6Supported)
+	lines := providerConf.OpenVPNConfig(connection, allSettings.VPN.OpenVPN)

 	fmt.Println(strings.Join(lines, "\n"))
 	return nil
--- a/internal/cli/update.go
+++ b/internal/cli/update.go
@@ -72,7 +72,7 @@ func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) e

 	storage, err := storage.New(logger, constants.ServersData)
 	if err != nil {
-		return fmt.Errorf("creating servers storage: %w", err)
+		return fmt.Errorf("cannot create servers storage: %w", err)
 	}

 	const clientTimeout = 10 * time.Second
@@ -88,13 +88,13 @@ func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) e
 	updater := updater.New(httpClient, storage, providers, logger)
 	err = updater.UpdateServers(ctx, options.Providers, options.MinRatio)
 	if err != nil {
-		return fmt.Errorf("updating server information: %w", err)
+		return fmt.Errorf("cannot update server information: %w", err)
 	}

 	if maintainerMode {
 		err := storage.FlushToFile(c.repoServersPath)
 		if err != nil {
-			return fmt.Errorf("writing servers data to embedded JSON file: %w", err)
+			return fmt.Errorf("cannot write servers data to embedded JSON file: %w", err)
 		}
 	}

--- a/internal/configuration/settings/dns.go
+++ b/internal/configuration/settings/dns.go
@@ -31,7 +31,7 @@ type DNS struct {
 func (d DNS) validate() (err error) {
 	err = d.DoT.validate()
 	if err != nil {
-		return fmt.Errorf("validating DoT settings: %w", err)
+		return fmt.Errorf("failed validating DoT settings: %w", err)
 	}

 	return nil
--- a/internal/configuration/settings/dot.go
+++ b/internal/configuration/settings/dot.go
@@ -65,7 +65,7 @@ func (d *DoT) copy() (copied DoT) {
 // unset field of the receiver settings object.
 func (d *DoT) mergeWith(other DoT) {
 	d.Enabled = helpers.MergeWithBool(d.Enabled, other.Enabled)
-	d.UpdatePeriod = helpers.MergeWithDurationPtr(d.UpdatePeriod, other.UpdatePeriod)
+	d.UpdatePeriod = helpers.MergeWithDuration(d.UpdatePeriod, other.UpdatePeriod)
 	d.Unbound.mergeWith(other.Unbound)
 	d.Blacklist.mergeWith(other.Blacklist)
 }
@@ -75,7 +75,7 @@ func (d *DoT) mergeWith(other DoT) {
 // settings.
 func (d *DoT) overrideWith(other DoT) {
 	d.Enabled = helpers.OverrideWithBool(d.Enabled, other.Enabled)
-	d.UpdatePeriod = helpers.OverrideWithDurationPtr(d.UpdatePeriod, other.UpdatePeriod)
+	d.UpdatePeriod = helpers.OverrideWithDuration(d.UpdatePeriod, other.UpdatePeriod)
 	d.Unbound.overrideWith(other.Unbound)
 	d.Blacklist.overrideWith(other.Blacklist)
 }
@@ -83,7 +83,7 @@ func (d *DoT) overrideWith(other DoT) {
 func (d *DoT) setDefaults() {
 	d.Enabled = helpers.DefaultBool(d.Enabled, true)
 	const defaultUpdatePeriod = 24 * time.Hour
-	d.UpdatePeriod = helpers.DefaultDurationPtr(d.UpdatePeriod, defaultUpdatePeriod)
+	d.UpdatePeriod = helpers.DefaultDuration(d.UpdatePeriod, defaultUpdatePeriod)
 	d.Unbound.setDefaults()
 	d.Blacklist.setDefaults()
 }
--- a/internal/configuration/settings/errors.go
+++ b/internal/configuration/settings/errors.go
@@ -17,7 +17,6 @@ var (
 	ErrOpenVPNCustomPortNotAllowed     = errors.New("custom endpoint port is not allowed")
 	ErrOpenVPNEncryptionPresetNotValid = errors.New("PIA encryption preset is not valid")
 	ErrOpenVPNInterfaceNotValid        = errors.New("interface name is not valid")
-	ErrOpenVPNKeyPassphraseIsEmpty     = errors.New("key passphrase is empty")
 	ErrOpenVPNMSSFixIsTooHigh          = errors.New("mssfix option value is too high")
 	ErrOpenVPNPasswordIsEmpty          = errors.New("password is empty")
 	ErrOpenVPNTCPNotSupported          = errors.New("TCP protocol is not supported")
@@ -37,13 +36,10 @@ var (
 	ErrWireguardEndpointIPNotSet       = errors.New("endpoint IP is not set")
 	ErrWireguardEndpointPortNotAllowed = errors.New("endpoint port is not allowed")
 	ErrWireguardEndpointPortNotSet     = errors.New("endpoint port is not set")
-	ErrWireguardEndpointPortSet        = errors.New("endpoint port is set")
 	ErrWireguardInterfaceAddressNotSet = errors.New("interface address is not set")
-	ErrWireguardInterfaceAddressIPv6   = errors.New("interface address is IPv6 but IPv6 is not supported")
 	ErrWireguardInterfaceNotValid      = errors.New("interface name is not valid")
 	ErrWireguardPreSharedKeyNotSet     = errors.New("pre-shared key is not set")
 	ErrWireguardPrivateKeyNotSet       = errors.New("private key is not set")
 	ErrWireguardPublicKeyNotSet        = errors.New("public key is not set")
 	ErrWireguardPublicKeyNotValid      = errors.New("public key is not valid")
-	ErrWireguardImplementationNotValid = errors.New("implementation is not valid")
 )
--- a/internal/configuration/settings/firewall.go
+++ b/internal/configuration/settings/firewall.go
@@ -109,8 +109,7 @@ func (f Firewall) toLinesNode() (node *gotree.Node) {
 	if len(f.OutboundSubnets) > 0 {
 		outboundSubnets := node.Appendf("Outbound subnets:")
 		for _, subnet := range f.OutboundSubnets {
-			subnet := subnet
-			outboundSubnets.Appendf("%s", &subnet)
+			outboundSubnets.Appendf("%s", subnet)
 		}
 	}

--- a/internal/configuration/settings/health.go
+++ b/internal/configuration/settings/health.go
@@ -3,7 +3,6 @@ package settings
 import (
 	"fmt"
 	"os"
-	"time"

 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gotree"
@@ -16,12 +15,6 @@ type Health struct {
 	// for the health check server.
 	// It cannot be the empty string in the internal state.
 	ServerAddress string
-	// ReadHeaderTimeout is the HTTP server header read timeout
-	// duration of the HTTP server. It defaults to 100 milliseconds.
-	ReadHeaderTimeout time.Duration
-	// ReadTimeout is the HTTP read timeout duration of the
-	//  HTTP server. It defaults to 500 milliseconds.
-	ReadTimeout time.Duration
 	// TargetAddress is the address (host or host:port)
 	// to TCP dial to periodically for the health check.
 	// It cannot be the empty string in the internal state.
@@ -47,11 +40,9 @@ func (h Health) Validate() (err error) {

 func (h *Health) copy() (copied Health) {
 	return Health{
-		ServerAddress:     h.ServerAddress,
-		ReadHeaderTimeout: h.ReadHeaderTimeout,
-		ReadTimeout:       h.ReadTimeout,
-		TargetAddress:     h.TargetAddress,
-		VPN:               h.VPN.copy(),
+		ServerAddress: h.ServerAddress,
+		TargetAddress: h.TargetAddress,
+		VPN:           h.VPN.copy(),
 	}
 }

@@ -59,8 +50,6 @@ func (h *Health) copy() (copied Health) {
 // unset field of the receiver settings object.
 func (h *Health) MergeWith(other Health) {
 	h.ServerAddress = helpers.MergeWithString(h.ServerAddress, other.ServerAddress)
-	h.ReadHeaderTimeout = helpers.MergeWithDuration(h.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	h.ReadTimeout = helpers.MergeWithDuration(h.ReadTimeout, other.ReadTimeout)
 	h.TargetAddress = helpers.MergeWithString(h.TargetAddress, other.TargetAddress)
 	h.VPN.mergeWith(other.VPN)
 }
@@ -70,18 +59,12 @@ func (h *Health) MergeWith(other Health) {
 // settings.
 func (h *Health) OverrideWith(other Health) {
 	h.ServerAddress = helpers.OverrideWithString(h.ServerAddress, other.ServerAddress)
-	h.ReadHeaderTimeout = helpers.OverrideWithDuration(h.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	h.ReadTimeout = helpers.OverrideWithDuration(h.ReadTimeout, other.ReadTimeout)
 	h.TargetAddress = helpers.OverrideWithString(h.TargetAddress, other.TargetAddress)
 	h.VPN.overrideWith(other.VPN)
 }

 func (h *Health) SetDefaults() {
 	h.ServerAddress = helpers.DefaultString(h.ServerAddress, "127.0.0.1:9999")
-	const defaultReadHeaderTimeout = 100 * time.Millisecond
-	h.ReadHeaderTimeout = helpers.DefaultDuration(h.ReadHeaderTimeout, defaultReadHeaderTimeout)
-	const defaultReadTimeout = 500 * time.Millisecond
-	h.ReadTimeout = helpers.DefaultDuration(h.ReadTimeout, defaultReadTimeout)
 	h.TargetAddress = helpers.DefaultString(h.TargetAddress, "cloudflare.com:443")
 	h.VPN.setDefaults()
 }
@@ -94,8 +77,6 @@ func (h Health) toLinesNode() (node *gotree.Node) {
 	node = gotree.New("Health settings:")
 	node.Appendf("Server listening address: %s", h.ServerAddress)
 	node.Appendf("Target address: %s", h.TargetAddress)
-	node.Appendf("Read header timeout: %s", h.ReadHeaderTimeout)
-	node.Appendf("Read timeout: %s", h.ReadTimeout)
 	node.AppendNode(h.VPN.toLinesNode("VPN"))
 	return node
 }
--- a/internal/configuration/settings/healthywait.go
+++ b/internal/configuration/settings/healthywait.go
@@ -35,23 +35,23 @@ func (h *HealthyWait) copy() (copied HealthyWait) {
 // mergeWith merges the other settings into any
 // unset field of the receiver settings object.
 func (h *HealthyWait) mergeWith(other HealthyWait) {
-	h.Initial = helpers.MergeWithDurationPtr(h.Initial, other.Initial)
-	h.Addition = helpers.MergeWithDurationPtr(h.Addition, other.Addition)
+	h.Initial = helpers.MergeWithDuration(h.Initial, other.Initial)
+	h.Addition = helpers.MergeWithDuration(h.Addition, other.Addition)
 }

 // overrideWith overrides fields of the receiver
 // settings object with any field set in the other
 // settings.
 func (h *HealthyWait) overrideWith(other HealthyWait) {
-	h.Initial = helpers.OverrideWithDurationPtr(h.Initial, other.Initial)
-	h.Addition = helpers.OverrideWithDurationPtr(h.Addition, other.Addition)
+	h.Initial = helpers.OverrideWithDuration(h.Initial, other.Initial)
+	h.Addition = helpers.OverrideWithDuration(h.Addition, other.Addition)
 }

 func (h *HealthyWait) setDefaults() {
 	const initialDurationDefault = 6 * time.Second
 	const additionDurationDefault = 5 * time.Second
-	h.Initial = helpers.DefaultDurationPtr(h.Initial, initialDurationDefault)
-	h.Addition = helpers.DefaultDurationPtr(h.Addition, additionDurationDefault)
+	h.Initial = helpers.DefaultDuration(h.Initial, initialDurationDefault)
+	h.Addition = helpers.DefaultDuration(h.Addition, additionDurationDefault)
 }

 func (h HealthyWait) String() string {
--- a/internal/configuration/settings/helpers/default.go
+++ b/internal/configuration/settings/helpers/default.go
@@ -73,15 +73,7 @@ func DefaultStringPtr(existing *string, defaultValue string) (result *string) {
 	return result
 }

-func DefaultDuration(existing time.Duration,
-	defaultValue time.Duration) (result time.Duration) {
-	if existing != 0 {
-		return existing
-	}
-	return defaultValue
-}
-
-func DefaultDurationPtr(existing *time.Duration,
+func DefaultDuration(existing *time.Duration,
 	defaultValue time.Duration) (result *time.Duration) {
 	if existing != nil {
 		return existing
--- a/internal/configuration/settings/helpers/merge.go
+++ b/internal/configuration/settings/helpers/merge.go
@@ -107,14 +107,7 @@ func MergeWithIP(existing, other net.IP) (result net.IP) {
 	return result
 }

-func MergeWithDuration(existing, other time.Duration) (result time.Duration) {
-	if existing != 0 {
-		return existing
-	}
-	return other
-}
-
-func MergeWithDurationPtr(existing, other *time.Duration) (result *time.Duration) {
+func MergeWithDuration(existing, other *time.Duration) (result *time.Duration) {
 	if existing != nil {
 		return existing
 	}
--- a/internal/configuration/settings/helpers/override.go
+++ b/internal/configuration/settings/helpers/override.go
@@ -93,16 +93,7 @@ func OverrideWithIP(existing, other net.IP) (result net.IP) {
 	return result
 }

-func OverrideWithDuration(existing, other time.Duration) (
-	result time.Duration) {
-	if other == 0 {
-		return existing
-	}
-	return other
-}
-
-func OverrideWithDurationPtr(existing, other *time.Duration) (
-	result *time.Duration) {
+func OverrideWithDuration(existing, other *time.Duration) (result *time.Duration) {
 	if other == nil {
 		return existing
 	}
--- a/internal/configuration/settings/httpproxy.go
+++ b/internal/configuration/settings/httpproxy.go
@@ -3,7 +3,6 @@ package settings
 import (
 	"fmt"
 	"os"
-	"time"

 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gotree"
@@ -34,12 +33,6 @@ type HTTPProxy struct {
 	// each request/response. It cannot be nil in the
 	// internal state.
 	Log *bool
-	// ReadHeaderTimeout is the HTTP header read timeout duration
-	// of the HTTP server. It defaults to 1 second if left unset.
-	ReadHeaderTimeout time.Duration
-	// ReadTimeout is the HTTP read timeout duration
-	// of the HTTP server. It defaults to 3 seconds if left unset.
-	ReadTimeout time.Duration
 }

 func (h HTTPProxy) validate() (err error) {
@@ -56,14 +49,12 @@ func (h HTTPProxy) validate() (err error) {

 func (h *HTTPProxy) copy() (copied HTTPProxy) {
 	return HTTPProxy{
-		User:              helpers.CopyStringPtr(h.User),
-		Password:          helpers.CopyStringPtr(h.Password),
-		ListeningAddress:  h.ListeningAddress,
-		Enabled:           helpers.CopyBoolPtr(h.Enabled),
-		Stealth:           helpers.CopyBoolPtr(h.Stealth),
-		Log:               helpers.CopyBoolPtr(h.Log),
-		ReadHeaderTimeout: h.ReadHeaderTimeout,
-		ReadTimeout:       h.ReadTimeout,
+		User:             helpers.CopyStringPtr(h.User),
+		Password:         helpers.CopyStringPtr(h.Password),
+		ListeningAddress: h.ListeningAddress,
+		Enabled:          helpers.CopyBoolPtr(h.Enabled),
+		Stealth:          helpers.CopyBoolPtr(h.Stealth),
+		Log:              helpers.CopyBoolPtr(h.Log),
 	}
 }

@@ -76,8 +67,6 @@ func (h *HTTPProxy) mergeWith(other HTTPProxy) {
 	h.Enabled = helpers.MergeWithBool(h.Enabled, other.Enabled)
 	h.Stealth = helpers.MergeWithBool(h.Stealth, other.Stealth)
 	h.Log = helpers.MergeWithBool(h.Log, other.Log)
-	h.ReadHeaderTimeout = helpers.MergeWithDuration(h.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	h.ReadTimeout = helpers.MergeWithDuration(h.ReadTimeout, other.ReadTimeout)
 }

 // overrideWith overrides fields of the receiver
@@ -90,8 +79,6 @@ func (h *HTTPProxy) overrideWith(other HTTPProxy) {
 	h.Enabled = helpers.OverrideWithBool(h.Enabled, other.Enabled)
 	h.Stealth = helpers.OverrideWithBool(h.Stealth, other.Stealth)
 	h.Log = helpers.OverrideWithBool(h.Log, other.Log)
-	h.ReadHeaderTimeout = helpers.OverrideWithDuration(h.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	h.ReadTimeout = helpers.OverrideWithDuration(h.ReadTimeout, other.ReadTimeout)
 }

 func (h *HTTPProxy) setDefaults() {
@@ -101,10 +88,6 @@ func (h *HTTPProxy) setDefaults() {
 	h.Enabled = helpers.DefaultBool(h.Enabled, false)
 	h.Stealth = helpers.DefaultBool(h.Stealth, false)
 	h.Log = helpers.DefaultBool(h.Log, false)
-	const defaultReadHeaderTimeout = time.Second
-	h.ReadHeaderTimeout = helpers.DefaultDuration(h.ReadHeaderTimeout, defaultReadHeaderTimeout)
-	const defaultReadTimeout = 3 * time.Second
-	h.ReadTimeout = helpers.DefaultDuration(h.ReadTimeout, defaultReadTimeout)
 }

 func (h HTTPProxy) String() string {
@@ -123,8 +106,6 @@ func (h HTTPProxy) toLinesNode() (node *gotree.Node) {
 	node.Appendf("Password: %s", helpers.ObfuscatePassword(*h.Password))
 	node.Appendf("Stealth mode: %s", helpers.BoolPtrToYesNo(h.Stealth))
 	node.Appendf("Log: %s", helpers.BoolPtrToYesNo(h.Log))
-	node.Appendf("Read header timeout: %s", h.ReadHeaderTimeout)
-	node.Appendf("Read timeout: %s", h.ReadTimeout)

 	return node
 }
--- a/internal/configuration/settings/openvpn.go
+++ b/internal/configuration/settings/openvpn.go
@@ -20,15 +20,13 @@ type OpenVPN struct {
 	// It can only be "2.4" or "2.5".
 	Version string
 	// User is the OpenVPN authentication username.
-	// It cannot be nil in the internal state if OpenVPN is used.
-	// It is usually required but in some cases can be the empty string
-	// to indicate no user+password authentication is needed.
-	User *string
+	// It cannot be an empty string in the internal state
+	// if OpenVPN is used.
+	User string
 	// Password is the OpenVPN authentication password.
-	// It cannot be nil in the internal state if OpenVPN is used.
-	// It is usually required but in some cases can be the empty string
-	// to indicate no user+password authentication is needed.
-	Password *string
+	// It cannot be an empty string in the internal state
+	// if OpenVPN is used.
+	Password string
 	// ConfFile is a custom OpenVPN configuration file path.
 	// It can be set to the empty string for it to be ignored.
 	// It cannot be nil in the internal state.
@@ -42,29 +40,24 @@ type OpenVPN struct {
 	// It cannot be nil in the internal state.
 	// It is ignored if it is set to the empty string.
 	Auth *string
-	// Cert is the base64 encoded DER of an OpenVPN certificate for the <cert> block.
-	// This is notably used by Cyberghost and VPN secure.
+	// ClientCrt is the OpenVPN client certificate.
+	// This is notably used by Cyberghost.
 	// It can be set to the empty string to be ignored.
 	// It cannot be nil in the internal state.
-	Cert *string
-	// Key is the base64 encoded DER of an OpenVPN key.
+	ClientCrt *string
+	// ClientKey is the OpenVPN client key.
 	// This is used by Cyberghost and VPN Unlimited.
 	// It can be set to the empty string to be ignored.
 	// It cannot be nil in the internal state.
-	Key *string
-	// EncryptedKey is the base64 encoded DER of an encrypted key for OpenVPN.
-	// It is used by VPN secure.
-	// It defaults to the empty string meaning it is not
-	// to be used. KeyPassphrase must be set if this one is set.
-	EncryptedKey *string
-	// KeyPassphrase is the key passphrase to be used by OpenVPN
-	// to decrypt the EncryptedPrivateKey. It defaults to the
-	// empty string and must be set if EncryptedPrivateKey is set.
-	KeyPassphrase *string
+	ClientKey *string
 	// PIAEncPreset is the encryption preset for
 	// Private Internet Access. It can be set to an
 	// empty string for other providers.
 	PIAEncPreset *string
+	// IPv6 is set to true if IPv6 routing should be
+	// set to be tunnel in OpenVPN, and false otherwise.
+	// It cannot be nil in the internal state.
+	IPv6 *bool // TODO automate like with Wireguard
 	// MSSFix is the value (1 to 10000) to set for the
 	// mssfix option for OpenVPN. It is ignored if set to 0.
 	// It cannot be nil in the internal state.
@@ -95,18 +88,15 @@ func (o OpenVPN) validate(vpnProvider string) (err error) {
 	}

 	isCustom := vpnProvider == providers.Custom
-	isUserRequired := !isCustom &&
-		vpnProvider != providers.Airvpn &&
-		vpnProvider != providers.VPNSecure

-	if isUserRequired && *o.User == "" {
+	if !isCustom && o.User == "" {
 		return ErrOpenVPNUserIsEmpty
 	}

-	passwordRequired := isUserRequired &&
-		(vpnProvider != providers.Ivpn || !ivpnAccountID.MatchString(*o.User))
+	passwordRequired := !isCustom &&
+		(vpnProvider != providers.Ivpn || !ivpnAccountID.MatchString(o.User))

-	if passwordRequired && *o.Password == "" {
+	if passwordRequired && o.Password == "" {
 		return ErrOpenVPNPasswordIsEmpty
 	}

@@ -115,25 +105,16 @@ func (o OpenVPN) validate(vpnProvider string) (err error) {
 		return fmt.Errorf("custom configuration file: %w", err)
 	}

-	err = validateOpenVPNClientCertificate(vpnProvider, *o.Cert)
+	err = validateOpenVPNClientCertificate(vpnProvider, *o.ClientCrt)
 	if err != nil {
 		return fmt.Errorf("client certificate: %w", err)
 	}

-	err = validateOpenVPNClientKey(vpnProvider, *o.Key)
+	err = validateOpenVPNClientKey(vpnProvider, *o.ClientKey)
 	if err != nil {
 		return fmt.Errorf("client key: %w", err)
 	}

-	err = validateOpenVPNEncryptedKey(vpnProvider, *o.EncryptedKey)
-	if err != nil {
-		return fmt.Errorf("encrypted key: %w", err)
-	}
-
-	if *o.EncryptedKey != "" && *o.KeyPassphrase == "" {
-		return fmt.Errorf("%w", ErrOpenVPNKeyPassphraseIsEmpty)
-	}
-
 	const maxMSSFix = 10000
 	if *o.MSSFix > maxMSSFix {
 		return fmt.Errorf("%w: %d is over the maximum value of %d",
@@ -171,7 +152,7 @@ func validateOpenVPNConfigFilepath(isCustom bool,
 	extractor := extract.New()
 	_, _, err = extractor.Data(confFile)
 	if err != nil {
-		return fmt.Errorf("extracting information from custom configuration file: %w", err)
+		return fmt.Errorf("failed extracting information from custom configuration file: %w", err)
 	}

 	return nil
@@ -181,9 +162,7 @@ func validateOpenVPNClientCertificate(vpnProvider,
 	clientCert string) (err error) {
 	switch vpnProvider {
 	case
-		providers.Airvpn,
 		providers.Cyberghost,
-		providers.VPNSecure,
 		providers.VPNUnlimited:
 		if clientCert == "" {
 			return ErrMissingValue
@@ -204,7 +183,6 @@ func validateOpenVPNClientCertificate(vpnProvider,
 func validateOpenVPNClientKey(vpnProvider, clientKey string) (err error) {
 	switch vpnProvider {
 	case
-		providers.Airvpn,
 		providers.Cyberghost,
 		providers.VPNUnlimited,
 		providers.Wevpn:
@@ -224,41 +202,23 @@ func validateOpenVPNClientKey(vpnProvider, clientKey string) (err error) {
 	return nil
 }

-func validateOpenVPNEncryptedKey(vpnProvider,
-	encryptedPrivateKey string) (err error) {
-	if vpnProvider == providers.VPNSecure && encryptedPrivateKey == "" {
-		return ErrMissingValue
-	}
-
-	if encryptedPrivateKey == "" {
-		return nil
-	}
-
-	_, err = base64.StdEncoding.DecodeString(encryptedPrivateKey)
-	if err != nil {
-		return err
-	}
-	return nil
-}
-
 func (o *OpenVPN) copy() (copied OpenVPN) {
 	return OpenVPN{
-		Version:       o.Version,
-		User:          helpers.CopyStringPtr(o.User),
-		Password:      helpers.CopyStringPtr(o.Password),
-		ConfFile:      helpers.CopyStringPtr(o.ConfFile),
-		Ciphers:       helpers.CopyStringSlice(o.Ciphers),
-		Auth:          helpers.CopyStringPtr(o.Auth),
-		Cert:          helpers.CopyStringPtr(o.Cert),
-		Key:           helpers.CopyStringPtr(o.Key),
-		EncryptedKey:  helpers.CopyStringPtr(o.EncryptedKey),
-		KeyPassphrase: helpers.CopyStringPtr(o.KeyPassphrase),
-		PIAEncPreset:  helpers.CopyStringPtr(o.PIAEncPreset),
-		MSSFix:        helpers.CopyUint16Ptr(o.MSSFix),
-		Interface:     o.Interface,
-		ProcessUser:   o.ProcessUser,
-		Verbosity:     helpers.CopyIntPtr(o.Verbosity),
-		Flags:         helpers.CopyStringSlice(o.Flags),
+		Version:      o.Version,
+		User:         o.User,
+		Password:     o.Password,
+		ConfFile:     helpers.CopyStringPtr(o.ConfFile),
+		Ciphers:      helpers.CopyStringSlice(o.Ciphers),
+		Auth:         helpers.CopyStringPtr(o.Auth),
+		ClientCrt:    helpers.CopyStringPtr(o.ClientCrt),
+		ClientKey:    helpers.CopyStringPtr(o.ClientKey),
+		PIAEncPreset: helpers.CopyStringPtr(o.PIAEncPreset),
+		IPv6:         helpers.CopyBoolPtr(o.IPv6),
+		MSSFix:       helpers.CopyUint16Ptr(o.MSSFix),
+		Interface:    o.Interface,
+		ProcessUser:  o.ProcessUser,
+		Verbosity:    helpers.CopyIntPtr(o.Verbosity),
+		Flags:        helpers.CopyStringSlice(o.Flags),
 	}
 }

@@ -266,16 +226,15 @@ func (o *OpenVPN) copy() (copied OpenVPN) {
 // unset field of the receiver settings object.
 func (o *OpenVPN) mergeWith(other OpenVPN) {
 	o.Version = helpers.MergeWithString(o.Version, other.Version)
-	o.User = helpers.MergeWithStringPtr(o.User, other.User)
-	o.Password = helpers.MergeWithStringPtr(o.Password, other.Password)
+	o.User = helpers.MergeWithString(o.User, other.User)
+	o.Password = helpers.MergeWithString(o.Password, other.Password)
 	o.ConfFile = helpers.MergeWithStringPtr(o.ConfFile, other.ConfFile)
 	o.Ciphers = helpers.MergeStringSlices(o.Ciphers, other.Ciphers)
 	o.Auth = helpers.MergeWithStringPtr(o.Auth, other.Auth)
-	o.Cert = helpers.MergeWithStringPtr(o.Cert, other.Cert)
-	o.Key = helpers.MergeWithStringPtr(o.Key, other.Key)
-	o.EncryptedKey = helpers.MergeWithStringPtr(o.EncryptedKey, other.EncryptedKey)
-	o.KeyPassphrase = helpers.MergeWithStringPtr(o.KeyPassphrase, other.KeyPassphrase)
+	o.ClientCrt = helpers.MergeWithStringPtr(o.ClientCrt, other.ClientCrt)
+	o.ClientKey = helpers.MergeWithStringPtr(o.ClientKey, other.ClientKey)
 	o.PIAEncPreset = helpers.MergeWithStringPtr(o.PIAEncPreset, other.PIAEncPreset)
+	o.IPv6 = helpers.MergeWithBool(o.IPv6, other.IPv6)
 	o.MSSFix = helpers.MergeWithUint16(o.MSSFix, other.MSSFix)
 	o.Interface = helpers.MergeWithString(o.Interface, other.Interface)
 	o.ProcessUser = helpers.MergeWithString(o.ProcessUser, other.ProcessUser)
@@ -288,16 +247,15 @@ func (o *OpenVPN) mergeWith(other OpenVPN) {
 // settings.
 func (o *OpenVPN) overrideWith(other OpenVPN) {
 	o.Version = helpers.OverrideWithString(o.Version, other.Version)
-	o.User = helpers.OverrideWithStringPtr(o.User, other.User)
-	o.Password = helpers.OverrideWithStringPtr(o.Password, other.Password)
+	o.User = helpers.OverrideWithString(o.User, other.User)
+	o.Password = helpers.OverrideWithString(o.Password, other.Password)
 	o.ConfFile = helpers.OverrideWithStringPtr(o.ConfFile, other.ConfFile)
 	o.Ciphers = helpers.OverrideWithStringSlice(o.Ciphers, other.Ciphers)
 	o.Auth = helpers.OverrideWithStringPtr(o.Auth, other.Auth)
-	o.Cert = helpers.OverrideWithStringPtr(o.Cert, other.Cert)
-	o.Key = helpers.OverrideWithStringPtr(o.Key, other.Key)
-	o.EncryptedKey = helpers.OverrideWithStringPtr(o.EncryptedKey, other.EncryptedKey)
-	o.KeyPassphrase = helpers.OverrideWithStringPtr(o.KeyPassphrase, other.KeyPassphrase)
+	o.ClientCrt = helpers.OverrideWithStringPtr(o.ClientCrt, other.ClientCrt)
+	o.ClientKey = helpers.OverrideWithStringPtr(o.ClientKey, other.ClientKey)
 	o.PIAEncPreset = helpers.OverrideWithStringPtr(o.PIAEncPreset, other.PIAEncPreset)
+	o.IPv6 = helpers.OverrideWithBool(o.IPv6, other.IPv6)
 	o.MSSFix = helpers.OverrideWithUint16(o.MSSFix, other.MSSFix)
 	o.Interface = helpers.OverrideWithString(o.Interface, other.Interface)
 	o.ProcessUser = helpers.OverrideWithString(o.ProcessUser, other.ProcessUser)
@@ -307,25 +265,22 @@ func (o *OpenVPN) overrideWith(other OpenVPN) {

 func (o *OpenVPN) setDefaults(vpnProvider string) {
 	o.Version = helpers.DefaultString(o.Version, openvpn.Openvpn25)
-	o.User = helpers.DefaultStringPtr(o.User, "")
 	if vpnProvider == providers.Mullvad {
-		o.Password = helpers.DefaultStringPtr(o.Password, "m")
-	} else {
-		o.Password = helpers.DefaultStringPtr(o.Password, "")
+		o.Password = "m"
 	}

 	o.ConfFile = helpers.DefaultStringPtr(o.ConfFile, "")
 	o.Auth = helpers.DefaultStringPtr(o.Auth, "")
-	o.Cert = helpers.DefaultStringPtr(o.Cert, "")
-	o.Key = helpers.DefaultStringPtr(o.Key, "")
-	o.EncryptedKey = helpers.DefaultStringPtr(o.EncryptedKey, "")
-	o.KeyPassphrase = helpers.DefaultStringPtr(o.KeyPassphrase, "")
+	o.ClientCrt = helpers.DefaultStringPtr(o.ClientCrt, "")
+	o.ClientKey = helpers.DefaultStringPtr(o.ClientKey, "")

 	var defaultEncPreset string
 	if vpnProvider == providers.PrivateInternetAccess {
 		defaultEncPreset = presets.Strong
 	}
 	o.PIAEncPreset = helpers.DefaultStringPtr(o.PIAEncPreset, defaultEncPreset)
+
+	o.IPv6 = helpers.DefaultBool(o.IPv6, false)
 	o.MSSFix = helpers.DefaultUint16(o.MSSFix, 0)
 	o.Interface = helpers.DefaultString(o.Interface, "tun0")
 	o.ProcessUser = helpers.DefaultString(o.ProcessUser, "root")
@@ -339,8 +294,8 @@ func (o OpenVPN) String() string {
 func (o OpenVPN) toLinesNode() (node *gotree.Node) {
 	node = gotree.New("OpenVPN settings:")
 	node.Appendf("OpenVPN version: %s", o.Version)
-	node.Appendf("User: %s", helpers.ObfuscatePassword(*o.User))
-	node.Appendf("Password: %s", helpers.ObfuscatePassword(*o.Password))
+	node.Appendf("User: %s", helpers.ObfuscatePassword(o.User))
+	node.Appendf("Password: %s", helpers.ObfuscatePassword(o.Password))

 	if *o.ConfFile != "" {
 		node.Appendf("Custom configuration file: %s", *o.ConfFile)
@@ -354,23 +309,20 @@ func (o OpenVPN) toLinesNode() (node *gotree.Node) {
 		node.Appendf("Auth: %s", *o.Auth)
 	}

-	if *o.Cert != "" {
-		node.Appendf("Client crt: %s", helpers.ObfuscateData(*o.Cert))
+	if *o.ClientCrt != "" {
+		node.Appendf("Client crt: %s", helpers.ObfuscateData(*o.ClientCrt))
 	}

-	if *o.Key != "" {
-		node.Appendf("Client key: %s", helpers.ObfuscateData(*o.Key))
-	}
-
-	if *o.EncryptedKey != "" {
-		node.Appendf("Encrypted key: %s (key passhrapse %s)",
-			helpers.ObfuscateData(*o.EncryptedKey), helpers.ObfuscatePassword(*o.KeyPassphrase))
+	if *o.ClientKey != "" {
+		node.Appendf("Client key: %s", helpers.ObfuscateData(*o.ClientKey))
 	}

 	if *o.PIAEncPreset != "" {
 		node.Appendf("Private Internet Access encryption preset: %s", *o.PIAEncPreset)
 	}

+	node.Appendf("Tunnel IPv6: %s", helpers.BoolPtrToYesNo(o.IPv6))
+
 	if *o.MSSFix > 0 {
 		node.Appendf("MSS Fix: %d", *o.MSSFix)
 	}
--- a/internal/configuration/settings/openvpnselection.go
+++ b/internal/configuration/settings/openvpnselection.go
@@ -60,19 +60,13 @@ func (o OpenVPNSelection) validate(vpnProvider string) (err error) {
 		case providers.Expressvpn, providers.Fastestvpn,
 			providers.Ipvanish, providers.Nordvpn,
 			providers.Privado, providers.Purevpn,
-			providers.Surfshark, providers.VPNSecure,
-			providers.VPNUnlimited, providers.Vyprvpn:
+			providers.Surfshark, providers.VPNUnlimited,
+			providers.Vyprvpn:
 			return fmt.Errorf("%w: for VPN service provider %s",
 				ErrOpenVPNCustomPortNotAllowed, vpnProvider)
 		default:
 			var allowedTCP, allowedUDP []uint16
 			switch vpnProvider {
-			case providers.Airvpn:
-				allowedTCP = []uint16{
-					53, 80, 443, // IP in 1, 3
-					1194, 2018, 41185, // IP in 1, 2, 3, 4
-				}
-				allowedUDP = []uint16{53, 80, 443, 1194, 2018, 41185}
 			case providers.Ivpn:
 				allowedTCP = []uint16{80, 443, 1143}
 				allowedUDP = []uint16{53, 1194, 2049, 2050}
@@ -88,9 +82,6 @@ func (o OpenVPNSelection) validate(vpnProvider string) (err error) {
 			case providers.Protonvpn:
 				allowedTCP = []uint16{443, 5995, 8443}
 				allowedUDP = []uint16{80, 443, 1194, 4569, 5060}
-			case providers.SlickVPN:
-				allowedTCP = []uint16{443, 8080, 8888}
-				allowedUDP = []uint16{443, 8080, 8888}
 			case providers.Wevpn:
 				allowedTCP = []uint16{53, 1195, 1199, 2018}
 				allowedUDP = []uint16{80, 1194, 1198}
--- a/internal/configuration/settings/provider.go
+++ b/internal/configuration/settings/provider.go
@@ -30,11 +30,9 @@ func (p *Provider) validate(vpnType string, storage Storage) (err error) {
 		validNames = append(validNames, "pia") // Retro-compatibility
 	} else { // Wireguard
 		validNames = []string{
-			providers.Airvpn,
 			providers.Custom,
 			providers.Ivpn,
 			providers.Mullvad,
-			providers.Surfshark,
 			providers.Windscribe,
 		}
 	}
--- a/internal/configuration/settings/publicip.go
+++ b/internal/configuration/settings/publicip.go
@@ -48,18 +48,18 @@ func (p *PublicIP) copy() (copied PublicIP) {
 }

 func (p *PublicIP) mergeWith(other PublicIP) {
-	p.Period = helpers.MergeWithDurationPtr(p.Period, other.Period)
+	p.Period = helpers.MergeWithDuration(p.Period, other.Period)
 	p.IPFilepath = helpers.MergeWithStringPtr(p.IPFilepath, other.IPFilepath)
 }

 func (p *PublicIP) overrideWith(other PublicIP) {
-	p.Period = helpers.OverrideWithDurationPtr(p.Period, other.Period)
+	p.Period = helpers.OverrideWithDuration(p.Period, other.Period)
 	p.IPFilepath = helpers.OverrideWithStringPtr(p.IPFilepath, other.IPFilepath)
 }

 func (p *PublicIP) setDefaults() {
 	const defaultPeriod = 12 * time.Hour
-	p.Period = helpers.DefaultDurationPtr(p.Period, defaultPeriod)
+	p.Period = helpers.DefaultDuration(p.Period, defaultPeriod)
 	p.IPFilepath = helpers.DefaultStringPtr(p.IPFilepath, "/tmp/gluetun/ip")
 }

--- a/internal/configuration/settings/serverselection.go
+++ b/internal/configuration/settings/serverselection.go
@@ -45,10 +45,6 @@ type ServerSelection struct { //nolint:maligned
 	// FreeOnly is true if VPN servers that are not free should
 	// be filtered. This is used with ProtonVPN and VPN Unlimited.
 	FreeOnly *bool
-	// PremiumOnly is true if VPN servers that are not premium should
-	// be filtered. This is used with VPN Secure.
-	// TODO extend to providers using FreeOnly.
-	PremiumOnly *bool
 	// StreamOnly is true if VPN servers not for streaming should
 	// be filtered. This is used with VPNUnlimited.
 	StreamOnly *bool
@@ -67,10 +63,8 @@ type ServerSelection struct { //nolint:maligned
 var (
 	ErrOwnedOnlyNotSupported    = errors.New("owned only filter is not supported")
 	ErrFreeOnlyNotSupported     = errors.New("free only filter is not supported")
-	ErrPremiumOnlyNotSupported  = errors.New("premium only filter is not supported")
 	ErrStreamOnlyNotSupported   = errors.New("stream only filter is not supported")
 	ErrMultiHopOnlyNotSupported = errors.New("multi hop only filter is not supported")
-	ErrFreePremiumBothSet       = errors.New("free only and premium only filters are both set")
 )

 func (ss *ServerSelection) validate(vpnServiceProvider string,
@@ -109,18 +103,6 @@ func (ss *ServerSelection) validate(vpnServiceProvider string,
 			ErrFreeOnlyNotSupported, vpnServiceProvider)
 	}

-	if *ss.PremiumOnly &&
-		!helpers.IsOneOf(vpnServiceProvider,
-			providers.VPNSecure,
-		) {
-		return fmt.Errorf("%w: for VPN service provider %s",
-			ErrPremiumOnlyNotSupported, vpnServiceProvider)
-	}
-
-	if *ss.FreeOnly && *ss.PremiumOnly {
-		return ErrFreePremiumBothSet
-	}
-
 	if *ss.StreamOnly &&
 		!helpers.IsOneOf(vpnServiceProvider,
 			providers.Protonvpn,
@@ -212,7 +194,6 @@ func (ss *ServerSelection) copy() (copied ServerSelection) {
 		Numbers:      helpers.CopyUint16Slice(ss.Numbers),
 		OwnedOnly:    helpers.CopyBoolPtr(ss.OwnedOnly),
 		FreeOnly:     helpers.CopyBoolPtr(ss.FreeOnly),
-		PremiumOnly:  helpers.CopyBoolPtr(ss.PremiumOnly),
 		StreamOnly:   helpers.CopyBoolPtr(ss.StreamOnly),
 		MultiHopOnly: helpers.CopyBoolPtr(ss.MultiHopOnly),
 		OpenVPN:      ss.OpenVPN.copy(),
@@ -232,7 +213,6 @@ func (ss *ServerSelection) mergeWith(other ServerSelection) {
 	ss.Numbers = helpers.MergeUint16Slices(ss.Numbers, other.Numbers)
 	ss.OwnedOnly = helpers.MergeWithBool(ss.OwnedOnly, other.OwnedOnly)
 	ss.FreeOnly = helpers.MergeWithBool(ss.FreeOnly, other.FreeOnly)
-	ss.PremiumOnly = helpers.MergeWithBool(ss.PremiumOnly, other.PremiumOnly)
 	ss.StreamOnly = helpers.MergeWithBool(ss.StreamOnly, other.StreamOnly)
 	ss.MultiHopOnly = helpers.MergeWithBool(ss.MultiHopOnly, other.MultiHopOnly)

@@ -252,7 +232,6 @@ func (ss *ServerSelection) overrideWith(other ServerSelection) {
 	ss.Numbers = helpers.OverrideWithUint16Slice(ss.Numbers, other.Numbers)
 	ss.OwnedOnly = helpers.OverrideWithBool(ss.OwnedOnly, other.OwnedOnly)
 	ss.FreeOnly = helpers.OverrideWithBool(ss.FreeOnly, other.FreeOnly)
-	ss.PremiumOnly = helpers.OverrideWithBool(ss.PremiumOnly, other.PremiumOnly)
 	ss.StreamOnly = helpers.OverrideWithBool(ss.StreamOnly, other.StreamOnly)
 	ss.MultiHopOnly = helpers.OverrideWithBool(ss.MultiHopOnly, other.MultiHopOnly)
 	ss.OpenVPN.overrideWith(other.OpenVPN)
@@ -264,7 +243,6 @@ func (ss *ServerSelection) setDefaults(vpnProvider string) {
 	ss.TargetIP = helpers.DefaultIP(ss.TargetIP, net.IP{})
 	ss.OwnedOnly = helpers.DefaultBool(ss.OwnedOnly, false)
 	ss.FreeOnly = helpers.DefaultBool(ss.FreeOnly, false)
-	ss.PremiumOnly = helpers.DefaultBool(ss.PremiumOnly, false)
 	ss.StreamOnly = helpers.DefaultBool(ss.StreamOnly, false)
 	ss.MultiHopOnly = helpers.DefaultBool(ss.MultiHopOnly, false)
 	ss.OpenVPN.setDefaults(vpnProvider)
@@ -321,10 +299,6 @@ func (ss ServerSelection) toLinesNode() (node *gotree.Node) {
 		node.Appendf("Free only servers: yes")
 	}

-	if *ss.PremiumOnly {
-		node.Appendf("Premium only servers: yes")
-	}
-
 	if *ss.StreamOnly {
 		node.Appendf("Stream only servers: yes")
 	}
--- a/internal/configuration/settings/settings.go
+++ b/internal/configuration/settings/settings.go
@@ -3,10 +3,6 @@ package settings
 import (
 	"fmt"

-	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
-	"github.com/qdm12/gluetun/internal/constants/openvpn"
-	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/pprof"
 	"github.com/qdm12/gotree"
@@ -35,7 +31,7 @@ type Storage interface {
 // Validate validates all the settings and returns an error
 // if one of them is not valid.
 // TODO v4 remove pointer for receiver (because of Surfshark).
-func (s *Settings) Validate(storage Storage, ipv6Supported bool) (err error) {
+func (s *Settings) Validate(storage Storage) (err error) {
 	nameToValidation := map[string]func() error{
 		"control server":  s.ControlServer.validate,
 		"dns":             s.DNS.validate,
@@ -50,7 +46,7 @@ func (s *Settings) Validate(storage Storage, ipv6Supported bool) (err error) {
 		"version":         s.Version.validate,
 		// Pprof validation done in pprof constructor
 		"VPN": func() error {
-			return s.VPN.Validate(storage, ipv6Supported)
+			return s.VPN.validate(storage)
 		},
 	}

@@ -77,7 +73,7 @@ func (s *Settings) copy() (copied Settings) {
 		System:        s.System.copy(),
 		Updater:       s.Updater.copy(),
 		Version:       s.Version.copy(),
-		VPN:           s.VPN.Copy(),
+		VPN:           s.VPN.copy(),
 		Pprof:         s.Pprof.Copy(),
 	}
 }
@@ -99,7 +95,7 @@ func (s *Settings) MergeWith(other Settings) {
 }

 func (s *Settings) OverrideWith(other Settings,
-	storage Storage, ipv6Supported bool) (err error) {
+	storage Storage) (err error) {
 	patchedSettings := s.copy()
 	patchedSettings.ControlServer.overrideWith(other.ControlServer)
 	patchedSettings.DNS.overrideWith(other.DNS)
@@ -112,9 +108,9 @@ func (s *Settings) OverrideWith(other Settings,
 	patchedSettings.System.overrideWith(other.System)
 	patchedSettings.Updater.overrideWith(other.Updater)
 	patchedSettings.Version.overrideWith(other.Version)
-	patchedSettings.VPN.OverrideWith(other.VPN)
+	patchedSettings.VPN.overrideWith(other.VPN)
 	patchedSettings.Pprof.OverrideWith(other.Pprof)
-	err = patchedSettings.Validate(storage, ipv6Supported)
+	err = patchedSettings.Validate(storage)
 	if err != nil {
 		return err
 	}
@@ -161,37 +157,3 @@ func (s Settings) toLinesNode() (node *gotree.Node) {

 	return node
 }
-
-func (s Settings) Warnings() (warnings []string) {
-	if *s.VPN.Provider.Name == providers.HideMyAss {
-		warnings = append(warnings, "HideMyAss dropped support for Linux OpenVPN "+
-			" so this will likely not work anymore. See https://github.com/qdm12/gluetun/issues/1498.")
-	}
-
-	if helpers.IsOneOf(*s.VPN.Provider.Name, providers.SlickVPN) &&
-		s.VPN.Type == vpn.OpenVPN {
-		if s.VPN.OpenVPN.Version == openvpn.Openvpn24 {
-			warnings = append(warnings, "OpenVPN 2.4 uses OpenSSL 1.1.1 "+
-				"which allows the usage of weak security in today's standards. "+
-				"This can be ok if good security is enforced by the VPN provider. "+
-				"However, "+*s.VPN.Provider.Name+" uses weak security so you should use "+
-				"OpenVPN 2.5 to enforce good security practices.")
-		} else {
-			warnings = append(warnings, "OpenVPN 2.5 uses OpenSSL 3 "+
-				"which prohibits the usage of weak security in today's standards. "+
-				*s.VPN.Provider.Name+" uses weak security which is out "+
-				"of Gluetun's control so the only workaround is to allow such weaknesses "+
-				`using the OpenVPN option tls-cipher "DEFAULT:@SECLEVEL=0". `+
-				"You might want to reach to your provider so they upgrade their certificates. "+
-				"Once this is done, you will have to let the Gluetun maintainers know "+
-				"by creating an issue, attaching the new certificate and we will update Gluetun.")
-		}
-	}
-
-	if s.VPN.OpenVPN.Version == openvpn.Openvpn24 {
-		warnings = append(warnings, "OpenVPN 2.4 will be removed in release v3.34.0 (around June 2023). "+
-			"Please create an issue if you have a compelling reason to keep it.")
-	}
-
-	return warnings
-}
--- a/internal/configuration/settings/settings_test.go
+++ b/internal/configuration/settings/settings_test.go
@@ -34,6 +34,7 @@ func Test_Settings_String(t *testing.T) {
 |       ├── User: [not set]
 |       ├── Password: [not set]
 |       ├── Private Internet Access encryption preset: strong
+|       ├── Tunnel IPv6: no
 |       ├── Network interface: tun0
 |       ├── Run OpenVPN as: root
 |       └── Verbosity level: 1
@@ -66,8 +67,6 @@ func Test_Settings_String(t *testing.T) {
 ├── Health settings:
 |   ├── Server listening address: 127.0.0.1:9999
 |   ├── Target address: cloudflare.com:443
-|   ├── Read header timeout: 100ms
-|   ├── Read timeout: 500ms
 |   └── VPN wait durations:
 |       ├── Initial duration: 6s
 |       └── Additional duration: 5s
--- a/internal/configuration/settings/updater.go
+++ b/internal/configuration/settings/updater.go
@@ -73,7 +73,7 @@ func (u *Updater) copy() (copied Updater) {
 // mergeWith merges the other settings into any
 // unset field of the receiver settings object.
 func (u *Updater) mergeWith(other Updater) {
-	u.Period = helpers.MergeWithDurationPtr(u.Period, other.Period)
+	u.Period = helpers.MergeWithDuration(u.Period, other.Period)
 	u.DNSAddress = helpers.MergeWithString(u.DNSAddress, other.DNSAddress)
 	u.MinRatio = helpers.MergeWithFloat64(u.MinRatio, other.MinRatio)
 	u.Providers = helpers.MergeStringSlices(u.Providers, other.Providers)
@@ -83,14 +83,14 @@ func (u *Updater) mergeWith(other Updater) {
 // settings object with any field set in the other
 // settings.
 func (u *Updater) overrideWith(other Updater) {
-	u.Period = helpers.OverrideWithDurationPtr(u.Period, other.Period)
+	u.Period = helpers.OverrideWithDuration(u.Period, other.Period)
 	u.DNSAddress = helpers.OverrideWithString(u.DNSAddress, other.DNSAddress)
 	u.MinRatio = helpers.OverrideWithFloat64(u.MinRatio, other.MinRatio)
 	u.Providers = helpers.OverrideWithStringSlice(u.Providers, other.Providers)
 }

 func (u *Updater) SetDefaults(vpnProvider string) {
-	u.Period = helpers.DefaultDurationPtr(u.Period, 0)
+	u.Period = helpers.DefaultDuration(u.Period, 0)
 	u.DNSAddress = helpers.DefaultString(u.DNSAddress, "1.1.1.1:53")

 	if u.MinRatio == 0 {
--- a/internal/configuration/settings/vpn.go
+++ b/internal/configuration/settings/vpn.go
@@ -20,7 +20,7 @@ type VPN struct {
 }

 // TODO v4 remove pointer for receiver (because of Surfshark).
-func (v *VPN) Validate(storage Storage, ipv6Supported bool) (err error) {
+func (v *VPN) validate(storage Storage) (err error) {
 	// Validate Type
 	validVPNTypes := []string{vpn.OpenVPN, vpn.Wireguard}
 	if !helpers.IsOneOf(v.Type, validVPNTypes...) {
@@ -39,7 +39,7 @@ func (v *VPN) Validate(storage Storage, ipv6Supported bool) (err error) {
 			return fmt.Errorf("OpenVPN settings: %w", err)
 		}
 	} else {
-		err := v.Wireguard.validate(*v.Provider.Name, ipv6Supported)
+		err := v.Wireguard.validate(*v.Provider.Name)
 		if err != nil {
 			return fmt.Errorf("Wireguard settings: %w", err)
 		}
@@ -48,7 +48,7 @@ func (v *VPN) Validate(storage Storage, ipv6Supported bool) (err error) {
 	return nil
 }

-func (v *VPN) Copy() (copied VPN) {
+func (v *VPN) copy() (copied VPN) {
 	return VPN{
 		Type:      v.Type,
 		Provider:  v.Provider.copy(),
@@ -64,7 +64,7 @@ func (v *VPN) mergeWith(other VPN) {
 	v.Wireguard.mergeWith(other.Wireguard)
 }

-func (v *VPN) OverrideWith(other VPN) {
+func (v *VPN) overrideWith(other VPN) {
 	v.Type = helpers.OverrideWithString(v.Type, other.Type)
 	v.Provider.overrideWith(other.Provider)
 	v.OpenVPN.overrideWith(other.OpenVPN)
--- a/internal/configuration/settings/wireguard.go
+++ b/internal/configuration/settings/wireguard.go
@@ -27,23 +27,17 @@ type Wireguard struct {
 	// to create. It cannot be the empty string in the
 	// internal state.
 	Interface string
-	// Implementation is the Wireguard implementation to use.
-	// It can be "auto", "userspace" or "kernelspace".
-	// It defaults to "auto" and cannot be the empty string
-	// in the internal state.
-	Implementation string
 }

 var regexpInterfaceName = regexp.MustCompile(`^[a-zA-Z0-9_]+$`)

 // Validate validates Wireguard settings.
 // It should only be ran if the VPN type chosen is Wireguard.
-func (w Wireguard) validate(vpnProvider string, ipv6Supported bool) (err error) {
+func (w Wireguard) validate(vpnProvider string) (err error) {
 	if !helpers.IsOneOf(vpnProvider,
 		providers.Custom,
 		providers.Ivpn,
 		providers.Mullvad,
-		providers.Surfshark,
 		providers.Windscribe,
 	) {
 		// do not validate for VPN provider not supporting Wireguard
@@ -59,12 +53,6 @@ func (w Wireguard) validate(vpnProvider string, ipv6Supported bool) (err error)
 		return fmt.Errorf("private key is not valid: %w", err)
 	}

-	if vpnProvider == providers.Airvpn {
-		if *w.PreSharedKey == "" {
-			return fmt.Errorf("%w", ErrWireguardPreSharedKeyNotSet)
-		}
-	}
-
 	// Validate PreSharedKey
 	if *w.PreSharedKey != "" { // Note: this is optional
 		_, err = wgtypes.ParseKey(*w.PreSharedKey)
@@ -82,12 +70,6 @@ func (w Wireguard) validate(vpnProvider string, ipv6Supported bool) (err error)
 			return fmt.Errorf("%w: for address at index %d: %s",
 				ErrWireguardInterfaceAddressNotSet, i, ipNet.String())
 		}
-
-		ipv6Net := ipNet.IP.To4() == nil
-		if ipv6Net && !ipv6Supported {
-			return fmt.Errorf("%w: address %s",
-				ErrWireguardInterfaceAddressIPv6, ipNet)
-		}
 	}

 	// Validate interface
@@ -96,22 +78,15 @@ func (w Wireguard) validate(vpnProvider string, ipv6Supported bool) (err error)
 			ErrWireguardInterfaceNotValid, w.Interface, regexpInterfaceName)
 	}

-	validImplementations := []string{"auto", "userspace", "kernelspace"}
-	if !helpers.IsOneOf(w.Implementation, validImplementations...) {
-		return fmt.Errorf("%w: %s must be one of %s", ErrWireguardImplementationNotValid,
-			w.Implementation, helpers.ChoicesOrString(validImplementations))
-	}
-
 	return nil
 }

 func (w *Wireguard) copy() (copied Wireguard) {
 	return Wireguard{
-		PrivateKey:     helpers.CopyStringPtr(w.PrivateKey),
-		PreSharedKey:   helpers.CopyStringPtr(w.PreSharedKey),
-		Addresses:      helpers.CopyIPNetSlice(w.Addresses),
-		Interface:      w.Interface,
-		Implementation: w.Implementation,
+		PrivateKey:   helpers.CopyStringPtr(w.PrivateKey),
+		PreSharedKey: helpers.CopyStringPtr(w.PreSharedKey),
+		Addresses:    helpers.CopyIPNetSlice(w.Addresses),
+		Interface:    w.Interface,
 	}
 }

@@ -120,7 +95,6 @@ func (w *Wireguard) mergeWith(other Wireguard) {
 	w.PreSharedKey = helpers.MergeWithStringPtr(w.PreSharedKey, other.PreSharedKey)
 	w.Addresses = helpers.MergeIPNetsSlices(w.Addresses, other.Addresses)
 	w.Interface = helpers.MergeWithString(w.Interface, other.Interface)
-	w.Implementation = helpers.MergeWithString(w.Implementation, other.Implementation)
 }

 func (w *Wireguard) overrideWith(other Wireguard) {
@@ -128,14 +102,12 @@ func (w *Wireguard) overrideWith(other Wireguard) {
 	w.PreSharedKey = helpers.OverrideWithStringPtr(w.PreSharedKey, other.PreSharedKey)
 	w.Addresses = helpers.OverrideWithIPNetsSlice(w.Addresses, other.Addresses)
 	w.Interface = helpers.OverrideWithString(w.Interface, other.Interface)
-	w.Implementation = helpers.OverrideWithString(w.Implementation, other.Implementation)
 }

 func (w *Wireguard) setDefaults() {
 	w.PrivateKey = helpers.DefaultStringPtr(w.PrivateKey, "")
 	w.PreSharedKey = helpers.DefaultStringPtr(w.PreSharedKey, "")
 	w.Interface = helpers.DefaultString(w.Interface, "wg0")
-	w.Implementation = helpers.DefaultString(w.Implementation, "auto")
 }

 func (w Wireguard) String() string {
@@ -162,9 +134,5 @@ func (w Wireguard) toLinesNode() (node *gotree.Node) {

 	node.Appendf("Network interface: %s", w.Interface)

-	if w.Implementation != "auto" {
-		node.Appendf("Implementation: %s", w.Implementation)
-	}
-
 	return node
 }
--- a/internal/configuration/settings/wireguardselection.go
+++ b/internal/configuration/settings/wireguardselection.go
@@ -19,7 +19,7 @@ type WireguardSelection struct {
 	// in the internal state.
 	EndpointIP net.IP
 	// EndpointPort is a the server port to use for the VPN server.
-	// It is optional for VPN providers IVPN, Mullvad, Surfshark
+	// It is optional for VPN providers IVPN, Mullvad
 	// and Windscribe, and compulsory for the others.
 	// When optional, it can be set to 0 to indicate not use
 	// a custom endpoint port. It cannot be nil in the internal
@@ -36,9 +36,7 @@ type WireguardSelection struct {
 func (w WireguardSelection) validate(vpnProvider string) (err error) {
 	// Validate EndpointIP
 	switch vpnProvider {
-	case providers.Airvpn, providers.Ivpn, providers.Mullvad,
-		providers.Surfshark, providers.Windscribe:
-		// endpoint IP addresses are baked in
+	case providers.Ivpn, providers.Mullvad, providers.Windscribe: // endpoint IP addresses are baked in
 	case providers.Custom:
 		if len(w.EndpointIP) == 0 {
 			return ErrWireguardEndpointIPNotSet
@@ -53,12 +51,7 @@ func (w WireguardSelection) validate(vpnProvider string) (err error) {
 		if *w.EndpointPort == 0 {
 			return ErrWireguardEndpointPortNotSet
 		}
-	// EndpointPort cannot be set
-	case providers.Surfshark:
-		if *w.EndpointPort != 0 {
-			return ErrWireguardEndpointPortSet
-		}
-	case providers.Airvpn, providers.Ivpn, providers.Mullvad, providers.Windscribe:
+	case providers.Ivpn, providers.Mullvad, providers.Windscribe:
 		// EndpointPort is optional and can be 0
 		if *w.EndpointPort == 0 {
 			break // no custom endpoint port set
@@ -68,8 +61,6 @@ func (w WireguardSelection) validate(vpnProvider string) (err error) {
 		}
 		var allowed []uint16
 		switch vpnProvider {
-		case providers.Airvpn:
-			allowed = []uint16{1637, 47107}
 		case providers.Ivpn:
 			allowed = []uint16{2049, 2050, 53, 30587, 41893, 48574, 58237}
 		case providers.Windscribe:
@@ -87,9 +78,7 @@ func (w WireguardSelection) validate(vpnProvider string) (err error) {

 	// Validate PublicKey
 	switch vpnProvider {
-	case providers.Ivpn, providers.Mullvad,
-		providers.Surfshark, providers.Windscribe:
-		// public keys are baked in
+	case providers.Ivpn, providers.Mullvad, providers.Windscribe: // public keys are baked in
 	case providers.Custom:
 		if w.PublicKey == "" {
 			return ErrWireguardPublicKeyNotSet
--- a/internal/configuration/sources/env/dns.go
+++ b/internal/configuration/sources/env/dns.go
@@ -7,8 +7,8 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readDNS() (dns settings.DNS, err error) {
-	dns.ServerAddress, err = s.readDNSServerAddress()
+func (r *Reader) readDNS() (dns settings.DNS, err error) {
+	dns.ServerAddress, err = r.readDNSServerAddress()
 	if err != nil {
 		return dns, err
 	}
@@ -18,7 +18,7 @@ func (s *Source) readDNS() (dns settings.DNS, err error) {
 		return dns, fmt.Errorf("environment variable DNS_KEEP_NAMESERVER: %w", err)
 	}

-	dns.DoT, err = s.readDoT()
+	dns.DoT, err = r.readDoT()
 	if err != nil {
 		return dns, fmt.Errorf("DoT settings: %w", err)
 	}
@@ -26,22 +26,22 @@ func (s *Source) readDNS() (dns settings.DNS, err error) {
 	return dns, nil
 }

-func (s *Source) readDNSServerAddress() (address net.IP, err error) {
-	key, value := s.getEnvWithRetro("DNS_ADDRESS", "DNS_PLAINTEXT_ADDRESS")
-	if value == "" {
+func (r *Reader) readDNSServerAddress() (address net.IP, err error) {
+	key, s := r.getEnvWithRetro("DNS_ADDRESS", "DNS_PLAINTEXT_ADDRESS")
+	if s == "" {
 		return nil, nil
 	}

-	address = net.ParseIP(value)
+	address = net.ParseIP(s)
 	if address == nil {
-		return nil, fmt.Errorf("environment variable %s: %w: %s", key, ErrIPAddressParse, value)
+		return nil, fmt.Errorf("environment variable %s: %w: %s", key, ErrIPAddressParse, s)
 	}

 	// TODO remove in v4
 	if !address.Equal(net.IPv4(127, 0, 0, 1)) { //nolint:gomnd
-		s.warner.Warn(key + " is set to " + value +
+		r.warner.Warn(key + " is set to " + s +
 			" so the DNS over TLS (DoT) server will not be used." +
-			" The default value changed to 127.0.0.1 so it uses the internal DoT serves." +
+			" The default value changed to 127.0.0.1 so it uses the internal DoT server." +
 			" If the DoT server fails to start, the IPv4 address of the first plaintext DNS server" +
 			" corresponding to the first DoT provider chosen is used.")
 	}
--- a/internal/configuration/sources/env/dnsblacklist.go
+++ b/internal/configuration/sources/env/dnsblacklist.go
@@ -9,13 +9,13 @@ import (
 	"inet.af/netaddr"
 )

-func (s *Source) readDNSBlacklist() (blacklist settings.DNSBlacklist, err error) {
+func (r *Reader) readDNSBlacklist() (blacklist settings.DNSBlacklist, err error) {
 	blacklist.BlockMalicious, err = envToBoolPtr("BLOCK_MALICIOUS")
 	if err != nil {
 		return blacklist, fmt.Errorf("environment variable BLOCK_MALICIOUS: %w", err)
 	}

-	blacklist.BlockSurveillance, err = s.readBlockSurveillance()
+	blacklist.BlockSurveillance, err = r.readBlockSurveillance()
 	if err != nil {
 		return blacklist, err
 	}
@@ -36,8 +36,8 @@ func (s *Source) readDNSBlacklist() (blacklist settings.DNSBlacklist, err error)
 	return blacklist, nil
 }

-func (s *Source) readBlockSurveillance() (blocked *bool, err error) {
-	key, value := s.getEnvWithRetro("BLOCK_SURVEILLANCE", "BLOCK_NSA")
+func (r *Reader) readBlockSurveillance() (blocked *bool, err error) {
+	key, value := r.getEnvWithRetro("BLOCK_SURVEILLANCE", "BLOCK_NSA")
 	if value == "" {
 		return nil, nil //nolint:nilnil
 	}
--- a/internal/configuration/sources/env/dot.go
+++ b/internal/configuration/sources/env/dot.go
@@ -6,7 +6,7 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readDoT() (dot settings.DoT, err error) {
+func (r *Reader) readDoT() (dot settings.DoT, err error) {
 	dot.Enabled, err = envToBoolPtr("DOT")
 	if err != nil {
 		return dot, fmt.Errorf("environment variable DOT: %w", err)
@@ -22,7 +22,7 @@ func (s *Source) readDoT() (dot settings.DoT, err error) {
 		return dot, err
 	}

-	dot.Blacklist, err = s.readDNSBlacklist()
+	dot.Blacklist, err = r.readDNSBlacklist()
 	if err != nil {
 		return dot, err
 	}
--- a/internal/configuration/sources/env/firewall.go
+++ b/internal/configuration/sources/env/firewall.go
@@ -9,7 +9,7 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readFirewall() (firewall settings.Firewall, err error) {
+func (r *Reader) readFirewall() (firewall settings.Firewall, err error) {
 	vpnInputPortStrings := envToCSV("FIREWALL_VPN_INPUT_PORTS")
 	firewall.VPNInputPorts, err = stringsToPorts(vpnInputPortStrings)
 	if err != nil {
@@ -22,7 +22,7 @@ func (s *Source) readFirewall() (firewall settings.Firewall, err error) {
 		return firewall, fmt.Errorf("environment variable FIREWALL_INPUT_PORTS: %w", err)
 	}

-	outboundSubnetsKey, _ := s.getEnvWithRetro("FIREWALL_OUTBOUND_SUBNETS", "EXTRA_SUBNETS")
+	outboundSubnetsKey, _ := r.getEnvWithRetro("FIREWALL_OUTBOUND_SUBNETS", "EXTRA_SUBNETS")
 	outboundSubnetStrings := envToCSV(outboundSubnetsKey)
 	firewall.OutboundSubnets, err = stringsToIPNets(outboundSubnetStrings)
 	if err != nil {
@@ -73,7 +73,7 @@ func stringsToIPNets(ss []string) (ipNets []net.IPNet, err error) {
 	for i, s := range ss {
 		ip, ipNet, err := net.ParseCIDR(s)
 		if err != nil {
-			return nil, fmt.Errorf("parsing IP network %q: %w", s, err)
+			return nil, fmt.Errorf("cannot parse IP network %q: %w", s, err)
 		}
 		ipNet.IP = ip
 		ipNets[i] = *ipNet
--- a/internal/configuration/sources/env/health.go
+++ b/internal/configuration/sources/env/health.go
@@ -7,18 +7,18 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) ReadHealth() (health settings.Health, err error) {
+func (r *Reader) ReadHealth() (health settings.Health, err error) {
 	health.ServerAddress = getCleanedEnv("HEALTH_SERVER_ADDRESS")
-	_, health.TargetAddress = s.getEnvWithRetro("HEALTH_TARGET_ADDRESS", "HEALTH_ADDRESS_TO_PING")
+	_, health.TargetAddress = r.getEnvWithRetro("HEALTH_TARGET_ADDRESS", "HEALTH_ADDRESS_TO_PING")

-	health.VPN.Initial, err = s.readDurationWithRetro(
+	health.VPN.Initial, err = r.readDurationWithRetro(
 		"HEALTH_VPN_DURATION_INITIAL",
 		"HEALTH_OPENVPN_DURATION_INITIAL")
 	if err != nil {
 		return health, err
 	}

-	health.VPN.Addition, err = s.readDurationWithRetro(
+	health.VPN.Addition, err = r.readDurationWithRetro(
 		"HEALTH_VPN_DURATION_ADDITION",
 		"HEALTH_OPENVPN_DURATION_ADDITION")
 	if err != nil {
@@ -28,14 +28,14 @@ func (s *Source) ReadHealth() (health settings.Health, err error) {
 	return health, nil
 }

-func (s *Source) readDurationWithRetro(envKey, retroEnvKey string) (d *time.Duration, err error) {
-	envKey, value := s.getEnvWithRetro(envKey, retroEnvKey)
-	if value == "" {
+func (r *Reader) readDurationWithRetro(envKey, retroEnvKey string) (d *time.Duration, err error) {
+	envKey, s := r.getEnvWithRetro(envKey, retroEnvKey)
+	if s == "" {
 		return nil, nil //nolint:nilnil
 	}

 	d = new(time.Duration)
-	*d, err = time.ParseDuration(value)
+	*d, err = time.ParseDuration(s)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", envKey, err)
 	}
--- a/internal/configuration/sources/env/helpers.go
+++ b/internal/configuration/sources/env/helpers.go
@@ -137,7 +137,7 @@ func unsetEnvKeys(envKeys []string, err error) (newErr error) {
 	for _, envKey := range envKeys {
 		unsetErr := os.Unsetenv(envKey)
 		if unsetErr != nil && newErr == nil {
-			newErr = fmt.Errorf("unsetting environment variable %s: %w", envKey, unsetErr)
+			newErr = fmt.Errorf("cannot unset environment variable %s: %w", envKey, unsetErr)
 		}
 	}
 	return newErr
--- a/internal/configuration/sources/env/httproxy.go
+++ b/internal/configuration/sources/env/httproxy.go
@@ -7,12 +7,12 @@ import (
 	"github.com/qdm12/govalid/binary"
 )

-func (s *Source) readHTTPProxy() (httpProxy settings.HTTPProxy, err error) {
-	httpProxy.User = s.readHTTProxyUser()
-	httpProxy.Password = s.readHTTProxyPassword()
-	httpProxy.ListeningAddress = s.readHTTProxyListeningAddress()
+func (r *Reader) readHTTPProxy() (httpProxy settings.HTTPProxy, err error) {
+	httpProxy.User = r.readHTTProxyUser()
+	httpProxy.Password = r.readHTTProxyPassword()
+	httpProxy.ListeningAddress = r.readHTTProxyListeningAddress()

-	httpProxy.Enabled, err = s.readHTTProxyEnabled()
+	httpProxy.Enabled, err = r.readHTTProxyEnabled()
 	if err != nil {
 		return httpProxy, err
 	}
@@ -22,7 +22,7 @@ func (s *Source) readHTTPProxy() (httpProxy settings.HTTPProxy, err error) {
 		return httpProxy, fmt.Errorf("environment variable HTTPPROXY_STEALTH: %w", err)
 	}

-	httpProxy.Log, err = s.readHTTProxyLog()
+	httpProxy.Log, err = r.readHTTProxyLog()
 	if err != nil {
 		return httpProxy, err
 	}
@@ -30,38 +30,38 @@ func (s *Source) readHTTPProxy() (httpProxy settings.HTTPProxy, err error) {
 	return httpProxy, nil
 }

-func (s *Source) readHTTProxyUser() (user *string) {
-	_, value := s.getEnvWithRetro("HTTPPROXY_USER", "PROXY_USER", "TINYPROXY_USER")
-	if value != "" {
-		return &value
+func (r *Reader) readHTTProxyUser() (user *string) {
+	_, s := r.getEnvWithRetro("HTTPPROXY_USER", "PROXY_USER", "TINYPROXY_USER")
+	if s != "" {
+		return &s
 	}
 	return nil
 }

-func (s *Source) readHTTProxyPassword() (user *string) {
-	_, value := s.getEnvWithRetro("HTTPPROXY_PASSWORD", "PROXY_PASSWORD", "TINYPROXY_PASSWORD")
-	if value != "" {
-		return &value
+func (r *Reader) readHTTProxyPassword() (user *string) {
+	_, s := r.getEnvWithRetro("HTTPPROXY_PASSWORD", "PROXY_PASSWORD", "TINYPROXY_PASSWORD")
+	if s != "" {
+		return &s
 	}
 	return nil
 }

-func (s *Source) readHTTProxyListeningAddress() (listeningAddress string) {
-	key, value := s.getEnvWithRetro("HTTPPROXY_LISTENING_ADDRESS", "PROXY_PORT", "TINYPROXY_PORT", "HTTPPROXY_PORT")
+func (r *Reader) readHTTProxyListeningAddress() (listeningAddress string) {
+	key, value := r.getEnvWithRetro("HTTPPROXY_LISTENING_ADDRESS", "PROXY_PORT", "TINYPROXY_PORT", "HTTPPROXY_PORT")
 	if key == "HTTPPROXY_LISTENING_ADDRESS" {
 		return value
 	}
 	return ":" + value
 }

-func (s *Source) readHTTProxyEnabled() (enabled *bool, err error) {
-	key, value := s.getEnvWithRetro("HTTPPROXY", "PROXY", "TINYPROXY")
-	if value == "" {
+func (r *Reader) readHTTProxyEnabled() (enabled *bool, err error) {
+	key, s := r.getEnvWithRetro("HTTPPROXY", "PROXY", "TINYPROXY")
+	if s == "" {
 		return nil, nil //nolint:nilnil
 	}

 	enabled = new(bool)
-	*enabled, err = binary.Validate(value)
+	*enabled, err = binary.Validate(s)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
 	}
@@ -69,9 +69,9 @@ func (s *Source) readHTTProxyEnabled() (enabled *bool, err error) {
 	return enabled, nil
 }

-func (s *Source) readHTTProxyLog() (enabled *bool, err error) {
-	key, value := s.getEnvWithRetro("HTTPPROXY_LOG", "PROXY_LOG_LEVEL", "TINYPROXY_LOG")
-	if value == "" {
+func (r *Reader) readHTTProxyLog() (enabled *bool, err error) {
+	key, s := r.getEnvWithRetro("HTTPPROXY_LOG", "PROXY_LOG_LEVEL", "TINYPROXY_LOG")
+	if s == "" {
 		return nil, nil //nolint:nilnil
 	}

@@ -82,7 +82,7 @@ func (s *Source) readHTTProxyLog() (enabled *bool, err error) {
 	}

 	enabled = new(bool)
-	*enabled, err = binary.Validate(value, binaryOptions...)
+	*enabled, err = binary.Validate(s, binaryOptions...)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
 	}
--- a/internal/configuration/sources/env/openvpn.go
+++ b/internal/configuration/sources/env/openvpn.go
@@ -8,22 +8,21 @@ import (
 	"github.com/qdm12/govalid/binary"
 )

-func (s *Source) readOpenVPN() (
+func (r *Reader) readOpenVPN() (
 	openVPN settings.OpenVPN, err error) {
 	defer func() {
-		err = unsetEnvKeys([]string{"OPENVPN_KEY", "OPENVPN_CERT",
-			"OPENVPN_KEY_PASSPHRASE", "OPENVPN_ENCRYPTED_KEY"}, err)
+		err = unsetEnvKeys([]string{"OPENVPN_CLIENTKEY", "OPENVPN_CLIENTCRT"}, err)
 	}()

 	openVPN.Version = getCleanedEnv("OPENVPN_VERSION")
-	openVPN.User = s.readOpenVPNUser()
-	openVPN.Password = s.readOpenVPNPassword()
+	openVPN.User = r.readOpenVPNUser()
+	openVPN.Password = r.readOpenVPNPassword()
 	confFile := getCleanedEnv("OPENVPN_CUSTOM_CONFIG")
 	if confFile != "" {
 		openVPN.ConfFile = &confFile
 	}

-	ciphersKey, _ := s.getEnvWithRetro("OPENVPN_CIPHERS", "OPENVPN_CIPHER")
+	ciphersKey, _ := r.getEnvWithRetro("OPENVPN_CIPHERS", "OPENVPN_CIPHER")
 	openVPN.Ciphers = envToCSV(ciphersKey)

 	auth := getCleanedEnv("OPENVPN_AUTH")
@@ -31,22 +30,24 @@ func (s *Source) readOpenVPN() (
 		openVPN.Auth = &auth
 	}

-	openVPN.Cert = envToStringPtr("OPENVPN_CERT")
-	openVPN.Key = envToStringPtr("OPENVPN_KEY")
-	openVPN.EncryptedKey = envToStringPtr("OPENVPN_ENCRYPTED_KEY")
+	openVPN.ClientCrt = envToStringPtr("OPENVPN_CLIENTCRT")
+	openVPN.ClientKey = envToStringPtr("OPENVPN_CLIENTKEY")

-	openVPN.KeyPassphrase = s.readOpenVPNKeyPassphrase()
+	openVPN.PIAEncPreset = r.readPIAEncryptionPreset()

-	openVPN.PIAEncPreset = s.readPIAEncryptionPreset()
+	openVPN.IPv6, err = envToBoolPtr("OPENVPN_IPV6")
+	if err != nil {
+		return openVPN, fmt.Errorf("environment variable OPENVPN_IPV6: %w", err)
+	}

 	openVPN.MSSFix, err = envToUint16Ptr("OPENVPN_MSSFIX")
 	if err != nil {
 		return openVPN, fmt.Errorf("environment variable OPENVPN_MSSFIX: %w", err)
 	}

-	_, openVPN.Interface = s.getEnvWithRetro("VPN_INTERFACE", "OPENVPN_INTERFACE")
+	_, openVPN.Interface = r.getEnvWithRetro("VPN_INTERFACE", "OPENVPN_INTERFACE")

-	openVPN.ProcessUser, err = s.readOpenVPNProcessUser()
+	openVPN.ProcessUser, err = r.readOpenVPNProcessUser()
 	if err != nil {
 		return openVPN, err
 	}
@@ -64,39 +65,19 @@ func (s *Source) readOpenVPN() (
 	return openVPN, nil
 }

-func (s *Source) readOpenVPNUser() (user *string) {
-	user = new(string)
-	_, *user = s.getEnvWithRetro("OPENVPN_USER", "USER")
-	if *user == "" {
-		return nil
-	}
-
+func (r *Reader) readOpenVPNUser() (user string) {
+	_, user = r.getEnvWithRetro("OPENVPN_USER", "USER")
 	// Remove spaces in user ID to simplify user's life, thanks @JeordyR
-	*user = strings.ReplaceAll(*user, " ", "")
-	return user
+	return strings.ReplaceAll(user, " ", "")
 }

-func (s *Source) readOpenVPNPassword() (password *string) {
-	password = new(string)
-	_, *password = s.getEnvWithRetro("OPENVPN_PASSWORD", "PASSWORD")
-	if *password == "" {
-		return nil
-	}
-
+func (r *Reader) readOpenVPNPassword() (password string) {
+	_, password = r.getEnvWithRetro("OPENVPN_PASSWORD", "PASSWORD")
 	return password
 }

-func (s *Source) readOpenVPNKeyPassphrase() (passphrase *string) {
-	passphrase = new(string)
-	*passphrase = getCleanedEnv("OPENVPN_KEY_PASSPHRASE")
-	if *passphrase == "" {
-		return nil
-	}
-	return passphrase
-}
-
-func (s *Source) readPIAEncryptionPreset() (presetPtr *string) {
-	_, preset := s.getEnvWithRetro(
+func (r *Reader) readPIAEncryptionPreset() (presetPtr *string) {
+	_, preset := r.getEnvWithRetro(
 		"PRIVATE_INTERNET_ACCESS_OPENVPN_ENCRYPTION_PRESET",
 		"PIA_ENCRYPTION", "ENCRYPTION")
 	if preset != "" {
@@ -105,8 +86,8 @@ func (s *Source) readPIAEncryptionPreset() (presetPtr *string) {
 	return nil
 }

-func (s *Source) readOpenVPNProcessUser() (processUser string, err error) {
-	key, value := s.getEnvWithRetro("OPENVPN_PROCESS_USER", "OPENVPN_ROOT")
+func (r *Reader) readOpenVPNProcessUser() (processUser string, err error) {
+	key, value := r.getEnvWithRetro("OPENVPN_PROCESS_USER", "OPENVPN_ROOT")
 	if key == "OPENVPN_PROCESS_USER" {
 		return value, nil
 	}
--- a/internal/configuration/sources/env/openvpnselection.go
+++ b/internal/configuration/sources/env/openvpnselection.go
@@ -10,32 +10,32 @@ import (
 	"github.com/qdm12/govalid/port"
 )

-func (s *Source) readOpenVPNSelection() (
+func (r *Reader) readOpenVPNSelection() (
 	selection settings.OpenVPNSelection, err error) {
 	confFile := getCleanedEnv("OPENVPN_CUSTOM_CONFIG")
 	if confFile != "" {
 		selection.ConfFile = &confFile
 	}

-	selection.TCP, err = s.readOpenVPNProtocol()
+	selection.TCP, err = r.readOpenVPNProtocol()
 	if err != nil {
 		return selection, err
 	}

-	selection.CustomPort, err = s.readOpenVPNCustomPort()
+	selection.CustomPort, err = r.readOpenVPNCustomPort()
 	if err != nil {
 		return selection, err
 	}

-	selection.PIAEncPreset = s.readPIAEncryptionPreset()
+	selection.PIAEncPreset = r.readPIAEncryptionPreset()

 	return selection, nil
 }

 var ErrOpenVPNProtocolNotValid = errors.New("OpenVPN protocol is not valid")

-func (s *Source) readOpenVPNProtocol() (tcp *bool, err error) {
-	envKey, protocol := s.getEnvWithRetro("OPENVPN_PROTOCOL", "PROTOCOL")
+func (r *Reader) readOpenVPNProtocol() (tcp *bool, err error) {
+	envKey, protocol := r.getEnvWithRetro("OPENVPN_PROTOCOL", "PROTOCOL")

 	switch strings.ToLower(protocol) {
 	case "":
@@ -50,14 +50,14 @@ func (s *Source) readOpenVPNProtocol() (tcp *bool, err error) {
 	}
 }

-func (s *Source) readOpenVPNCustomPort() (customPort *uint16, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", "PORT", "OPENVPN_PORT")
-	if value == "" {
+func (r *Reader) readOpenVPNCustomPort() (customPort *uint16, err error) {
+	key, s := r.getEnvWithRetro("VPN_ENDPOINT_PORT", "PORT", "OPENVPN_PORT")
+	if s == "" {
 		return nil, nil //nolint:nilnil
 	}

 	customPort = new(uint16)
-	*customPort, err = port.Validate(value)
+	*customPort, err = port.Validate(s)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
 	}
--- a/internal/configuration/sources/env/portforward.go
+++ b/internal/configuration/sources/env/portforward.go
@@ -6,9 +6,9 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readPortForward() (
+func (r *Reader) readPortForward() (
 	portForwarding settings.PortForwarding, err error) {
-	key, _ := s.getEnvWithRetro(
+	key, _ := r.getEnvWithRetro(
 		"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING",
 		"PORT_FORWARDING")
 	portForwarding.Enabled, err = envToBoolPtr(key)
@@ -16,7 +16,7 @@ func (s *Source) readPortForward() (
 		return portForwarding, fmt.Errorf("environment variable %s: %w", key, err)
 	}

-	_, value := s.getEnvWithRetro(
+	_, value := r.getEnvWithRetro(
 		"PRIVATE_INTERNET_ACCESS_VPN_PORT_FORWARDING_STATUS_FILE",
 		"PORT_FORWARDING_STATUS_FILE")
 	if value != "" {
--- a/internal/configuration/sources/env/provider.go
+++ b/internal/configuration/sources/env/provider.go
@@ -9,19 +9,19 @@ import (
 	"github.com/qdm12/gluetun/internal/constants/vpn"
 )

-func (s *Source) readProvider(vpnType string) (provider settings.Provider, err error) {
-	provider.Name = s.readVPNServiceProvider(vpnType)
+func (r *Reader) readProvider(vpnType string) (provider settings.Provider, err error) {
+	provider.Name = r.readVPNServiceProvider(vpnType)
 	var providerName string
 	if provider.Name != nil {
 		providerName = *provider.Name
 	}

-	provider.ServerSelection, err = s.readServerSelection(providerName, vpnType)
+	provider.ServerSelection, err = r.readServerSelection(providerName, vpnType)
 	if err != nil {
 		return provider, fmt.Errorf("server selection: %w", err)
 	}

-	provider.PortForwarding, err = s.readPortForward()
+	provider.PortForwarding, err = r.readPortForward()
 	if err != nil {
 		return provider, fmt.Errorf("port forwarding: %w", err)
 	}
@@ -29,20 +29,17 @@ func (s *Source) readProvider(vpnType string) (provider settings.Provider, err e
 	return provider, nil
 }

-func (s *Source) readVPNServiceProvider(vpnType string) (vpnProviderPtr *string) {
-	_, value := s.getEnvWithRetro("VPN_SERVICE_PROVIDER", "VPNSP")
-	if value == "" {
-		if vpnType != vpn.Wireguard && getCleanedEnv("OPENVPN_CUSTOM_CONFIG") != "" {
-			// retro compatibility
-			return stringPtr(providers.Custom)
-		}
+func (r *Reader) readVPNServiceProvider(vpnType string) (vpnProviderPtr *string) {
+	_, s := r.getEnvWithRetro("VPN_SERVICE_PROVIDER", "VPNSP")
+	s = strings.ToLower(s)
+	switch {
+	case vpnType != vpn.Wireguard &&
+		getCleanedEnv("OPENVPN_CUSTOM_CONFIG") != "": // retro compatibility
+		return stringPtr(providers.Custom)
+	case s == "":
 		return nil
-	}
-
-	value = strings.ToLower(value)
-	if value == "pia" { // retro compatibility
+	case s == "pia": // retro compatibility
 		return stringPtr(providers.PrivateInternetAccess)
 	}
-
-	return stringPtr(value)
+	return stringPtr(s)
 }
--- a/internal/configuration/sources/env/publicip.go
+++ b/internal/configuration/sources/env/publicip.go
@@ -7,13 +7,13 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readPublicIP() (publicIP settings.PublicIP, err error) {
+func (r *Reader) readPublicIP() (publicIP settings.PublicIP, err error) {
 	publicIP.Period, err = readPublicIPPeriod()
 	if err != nil {
 		return publicIP, err
 	}

-	publicIP.IPFilepath = s.readPublicIPFilepath()
+	publicIP.IPFilepath = r.readPublicIPFilepath()

 	return publicIP, nil
 }
@@ -33,10 +33,10 @@ func readPublicIPPeriod() (period *time.Duration, err error) {
 	return period, nil
 }

-func (s *Source) readPublicIPFilepath() (filepath *string) {
-	_, value := s.getEnvWithRetro("PUBLICIP_FILE", "IP_STATUS_FILE")
-	if value != "" {
-		return &value
+func (r *Reader) readPublicIPFilepath() (filepath *string) {
+	_, s := r.getEnvWithRetro("PUBLICIP_FILE", "IP_STATUS_FILE")
+	if s != "" {
+		return &s
 	}
 	return nil
 }
--- a/internal/configuration/sources/env/reader.go
+++ b/internal/configuration/sources/env/reader.go
@@ -2,9 +2,12 @@ package env

 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/configuration/sources"
 )

-type Source struct {
+var _ sources.Source = (*Reader)(nil)
+
+type Reader struct {
 	warner Warner
 }

@@ -12,36 +15,36 @@ type Warner interface {
 	Warn(s string)
 }

-func New(warner Warner) *Source {
-	return &Source{
+func New(warner Warner) *Reader {
+	return &Reader{
 		warner: warner,
 	}
 }

-func (s *Source) String() string { return "environment variables" }
+func (r *Reader) String() string { return "environment variables" }

-func (s *Source) Read() (settings settings.Settings, err error) {
-	settings.VPN, err = s.readVPN()
+func (r *Reader) Read() (settings settings.Settings, err error) {
+	settings.VPN, err = r.readVPN()
 	if err != nil {
 		return settings, err
 	}

-	settings.Firewall, err = s.readFirewall()
+	settings.Firewall, err = r.readFirewall()
 	if err != nil {
 		return settings, err
 	}

-	settings.System, err = s.readSystem()
+	settings.System, err = r.readSystem()
 	if err != nil {
 		return settings, err
 	}

-	settings.Health, err = s.ReadHealth()
+	settings.Health, err = r.ReadHealth()
 	if err != nil {
 		return settings, err
 	}

-	settings.HTTPProxy, err = s.readHTTPProxy()
+	settings.HTTPProxy, err = r.readHTTPProxy()
 	if err != nil {
 		return settings, err
 	}
@@ -51,7 +54,7 @@ func (s *Source) Read() (settings settings.Settings, err error) {
 		return settings, err
 	}

-	settings.PublicIP, err = s.readPublicIP()
+	settings.PublicIP, err = r.readPublicIP()
 	if err != nil {
 		return settings, err
 	}
@@ -66,17 +69,17 @@ func (s *Source) Read() (settings settings.Settings, err error) {
 		return settings, err
 	}

-	settings.Shadowsocks, err = s.readShadowsocks()
+	settings.Shadowsocks, err = r.readShadowsocks()
 	if err != nil {
 		return settings, err
 	}

-	settings.DNS, err = s.readDNS()
+	settings.DNS, err = r.readDNS()
 	if err != nil {
 		return settings, err
 	}

-	settings.ControlServer, err = s.readControlServer()
+	settings.ControlServer, err = r.readControlServer()
 	if err != nil {
 		return settings, err
 	}
@@ -89,8 +92,8 @@ func (s *Source) Read() (settings settings.Settings, err error) {
 	return settings, nil
 }

-func (s *Source) onRetroActive(oldKey, newKey string) {
-	s.warner.Warn(
+func (r *Reader) onRetroActive(oldKey, newKey string) {
+	r.warner.Warn(
 		"You are using the old environment variable " + oldKey +
 			", please consider changing it to " + newKey)
 }
@@ -101,14 +104,14 @@ func (s *Source) onRetroActive(oldKey, newKey string) {
 // and end on returning the value corresponding to the currentKey.
 // Note retroKeys should be in order from oldest to most
 // recent retro-compatibility key.
-func (s *Source) getEnvWithRetro(currentKey string,
+func (r *Reader) getEnvWithRetro(currentKey string,
 	retroKeys ...string) (key, value string) {
 	// We check retro-compatibility keys first since
 	// the current key might be set in the Dockerfile.
 	for _, key = range retroKeys {
 		value = getCleanedEnv(key)
 		if value != "" {
-			s.onRetroActive(key, currentKey)
+			r.onRetroActive(key, currentKey)
 			return key, value
 		}
 	}
--- a/internal/configuration/sources/env/server.go
+++ b/internal/configuration/sources/env/server.go
@@ -7,13 +7,13 @@ import (
 	"github.com/qdm12/govalid/binary"
 )

-func (s *Source) readControlServer() (controlServer settings.ControlServer, err error) {
+func (r *Reader) readControlServer() (controlServer settings.ControlServer, err error) {
 	controlServer.Log, err = readControlServerLog()
 	if err != nil {
 		return controlServer, err
 	}

-	controlServer.Address = s.readControlServerAddress()
+	controlServer.Address = r.readControlServerAddress()

 	return controlServer, nil
 }
@@ -32,17 +32,17 @@ func readControlServerLog() (enabled *bool, err error) {
 	return &log, nil
 }

-func (s *Source) readControlServerAddress() (address *string) {
-	key, value := s.getEnvWithRetro("HTTP_CONTROL_SERVER_ADDRESS", "HTTP_CONTROL_SERVER_PORT")
-	if value == "" {
+func (r *Reader) readControlServerAddress() (address *string) {
+	key, s := r.getEnvWithRetro("HTTP_CONTROL_SERVER_ADDRESS", "HTTP_CONTROL_SERVER_PORT")
+	if s == "" {
 		return nil
 	}

 	if key == "HTTP_CONTROL_SERVER_ADDRESS" {
-		return &value
+		return &s
 	}

 	address = new(string)
-	*address = ":" + value
+	*address = ":" + s
 	return address
 }
--- a/internal/configuration/sources/env/serverselection.go
+++ b/internal/configuration/sources/env/serverselection.go
@@ -15,45 +15,44 @@ var (
 	ErrServerNumberNotValid = errors.New("server number is not valid")
 )

-func (s *Source) readServerSelection(vpnProvider, vpnType string) (
+func (r *Reader) readServerSelection(vpnProvider, vpnType string) (
 	ss settings.ServerSelection, err error) {
 	ss.VPN = vpnType

-	ss.TargetIP, err = s.readOpenVPNTargetIP()
+	ss.TargetIP, err = r.readOpenVPNTargetIP()
 	if err != nil {
 		return ss, err
 	}

-	countriesKey, _ := s.getEnvWithRetro("SERVER_COUNTRIES", "COUNTRY")
+	countriesKey, _ := r.getEnvWithRetro("SERVER_COUNTRIES", "COUNTRY")
 	ss.Countries = envToCSV(countriesKey)
 	if vpnProvider == providers.Cyberghost && len(ss.Countries) == 0 {
 		// Retro-compatibility for Cyberghost using the REGION variable
 		ss.Countries = envToCSV("REGION")
 		if len(ss.Countries) > 0 {
-			s.onRetroActive("REGION", "SERVER_COUNTRIES")
+			r.onRetroActive("REGION", "SERVER_COUNTRIES")
 		}
 	}

-	regionsKey, _ := s.getEnvWithRetro("SERVER_REGIONS", "REGION")
+	regionsKey, _ := r.getEnvWithRetro("SERVER_REGIONS", "REGION")
 	ss.Regions = envToCSV(regionsKey)

-	citiesKey, _ := s.getEnvWithRetro("SERVER_CITIES", "CITY")
+	citiesKey, _ := r.getEnvWithRetro("SERVER_CITIES", "CITY")
 	ss.Cities = envToCSV(citiesKey)

 	ss.ISPs = envToCSV("ISP")

-	hostnamesKey, _ := s.getEnvWithRetro("SERVER_HOSTNAMES", "SERVER_HOSTNAME")
+	hostnamesKey, _ := r.getEnvWithRetro("SERVER_HOSTNAMES", "SERVER_HOSTNAME")
 	ss.Hostnames = envToCSV(hostnamesKey)

-	serverNamesKey, _ := s.getEnvWithRetro("SERVER_NAMES", "SERVER_NAME")
+	serverNamesKey, _ := r.getEnvWithRetro("SERVER_NAMES", "SERVER_NAME")
 	ss.Names = envToCSV(serverNamesKey)

 	if csv := getCleanedEnv("SERVER_NUMBER"); csv != "" {
 		numbersStrings := strings.Split(csv, ",")
 		numbers := make([]uint16, len(numbersStrings))
 		for i, numberString := range numbersStrings {
-			const base, bitSize = 10, 16
-			number, err := strconv.ParseInt(numberString, base, bitSize)
+			number, err := strconv.Atoi(numberString)
 			if err != nil {
 				return ss, fmt.Errorf("%w: %s",
 					ErrServerNumberNotValid, numberString)
@@ -67,7 +66,7 @@ func (s *Source) readServerSelection(vpnProvider, vpnType string) (
 	}

 	// Mullvad only
-	ss.OwnedOnly, err = s.readOwnedOnly()
+	ss.OwnedOnly, err = r.readOwnedOnly()
 	if err != nil {
 		return ss, err
 	}
@@ -78,12 +77,6 @@ func (s *Source) readServerSelection(vpnProvider, vpnType string) (
 		return ss, fmt.Errorf("environment variable FREE_ONLY: %w", err)
 	}

-	// VPNSecure only
-	ss.PremiumOnly, err = envToBoolPtr("PREMIUM_ONLY")
-	if err != nil {
-		return ss, fmt.Errorf("environment variable PREMIUM_ONLY: %w", err)
-	}
-
 	// VPNUnlimited only
 	ss.MultiHopOnly, err = envToBoolPtr("MULTIHOP_ONLY")
 	if err != nil {
@@ -96,12 +89,12 @@ func (s *Source) readServerSelection(vpnProvider, vpnType string) (
 		return ss, fmt.Errorf("environment variable STREAM_ONLY: %w", err)
 	}

-	ss.OpenVPN, err = s.readOpenVPNSelection()
+	ss.OpenVPN, err = r.readOpenVPNSelection()
 	if err != nil {
 		return ss, err
 	}

-	ss.Wireguard, err = s.readWireguardSelection()
+	ss.Wireguard, err = r.readWireguardSelection()
 	if err != nil {
 		return ss, err
 	}
@@ -113,23 +106,23 @@ var (
 	ErrInvalidIP = errors.New("invalid IP address")
 )

-func (s *Source) readOpenVPNTargetIP() (ip net.IP, err error) {
-	envKey, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", "OPENVPN_TARGET_IP")
-	if value == "" {
+func (r *Reader) readOpenVPNTargetIP() (ip net.IP, err error) {
+	envKey, s := r.getEnvWithRetro("VPN_ENDPOINT_IP", "OPENVPN_TARGET_IP")
+	if s == "" {
 		return nil, nil
 	}

-	ip = net.ParseIP(value)
+	ip = net.ParseIP(s)
 	if ip == nil {
 		return nil, fmt.Errorf("environment variable %s: %w: %s",
-			envKey, ErrInvalidIP, value)
+			envKey, ErrInvalidIP, s)
 	}

 	return ip, nil
 }

-func (s *Source) readOwnedOnly() (ownedOnly *bool, err error) {
-	envKey, _ := s.getEnvWithRetro("OWNED_ONLY", "OWNED")
+func (r *Reader) readOwnedOnly() (ownedOnly *bool, err error) {
+	envKey, _ := r.getEnvWithRetro("OWNED_ONLY", "OWNED")
 	ownedOnly, err = envToBoolPtr(envKey)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", envKey, err)
--- a/internal/configuration/sources/env/shadowsocks.go
+++ b/internal/configuration/sources/env/shadowsocks.go
@@ -7,25 +7,25 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readShadowsocks() (shadowsocks settings.Shadowsocks, err error) {
+func (r *Reader) readShadowsocks() (shadowsocks settings.Shadowsocks, err error) {
 	shadowsocks.Enabled, err = envToBoolPtr("SHADOWSOCKS")
 	if err != nil {
 		return shadowsocks, fmt.Errorf("environment variable SHADOWSOCKS: %w", err)
 	}

-	shadowsocks.Address = s.readShadowsocksAddress()
+	shadowsocks.Address = r.readShadowsocksAddress()
 	shadowsocks.LogAddresses, err = envToBoolPtr("SHADOWSOCKS_LOG")
 	if err != nil {
 		return shadowsocks, fmt.Errorf("environment variable SHADOWSOCKS_LOG: %w", err)
 	}
-	shadowsocks.CipherName = s.readShadowsocksCipher()
+	shadowsocks.CipherName = r.readShadowsocksCipher()
 	shadowsocks.Password = envToStringPtr("SHADOWSOCKS_PASSWORD")

 	return shadowsocks, nil
 }

-func (s *Source) readShadowsocksAddress() (address string) {
-	key, value := s.getEnvWithRetro("SHADOWSOCKS_LISTENING_ADDRESS", "SHADOWSOCKS_PORT")
+func (r *Reader) readShadowsocksAddress() (address string) {
+	key, value := r.getEnvWithRetro("SHADOWSOCKS_LISTENING_ADDRESS", "SHADOWSOCKS_PORT")
 	if value == "" {
 		return ""
 	}
@@ -38,7 +38,7 @@ func (s *Source) readShadowsocksAddress() (address string) {
 	return ":" + value
 }

-func (s *Source) readShadowsocksCipher() (cipher string) {
-	_, cipher = s.getEnvWithRetro("SHADOWSOCKS_CIPHER", "SHADOWSOCKS_METHOD")
+func (r *Reader) readShadowsocksCipher() (cipher string) {
+	_, cipher = r.getEnvWithRetro("SHADOWSOCKS_CIPHER", "SHADOWSOCKS_METHOD")
 	return strings.ToLower(cipher)
 }
--- a/internal/configuration/sources/env/system.go
+++ b/internal/configuration/sources/env/system.go
@@ -14,13 +14,13 @@ var (
 	ErrSystemTimezoneNotValid = errors.New("timezone is not valid")
 )

-func (s *Source) readSystem() (system settings.System, err error) {
-	system.PUID, err = s.readID("PUID", "UID")
+func (r *Reader) readSystem() (system settings.System, err error) {
+	system.PUID, err = r.readID("PUID", "UID")
 	if err != nil {
 		return system, err
 	}

-	system.PGID, err = s.readID("PGID", "GID")
+	system.PGID, err = r.readID("PGID", "GID")
 	if err != nil {
 		return system, err
 	}
@@ -32,9 +32,9 @@ func (s *Source) readSystem() (system settings.System, err error) {

 var ErrSystemIDNotValid = errors.New("system ID is not valid")

-func (s *Source) readID(key, retroKey string) (
+func (r *Reader) readID(key, retroKey string) (
 	id *uint32, err error) {
-	idEnvKey, idString := s.getEnvWithRetro(key, retroKey)
+	idEnvKey, idString := r.getEnvWithRetro(key, retroKey)
 	if idString == "" {
 		return nil, nil //nolint:nilnil
 	}
--- a/internal/configuration/sources/env/system_test.go
+++ b/internal/configuration/sources/env/system_test.go
@@ -74,8 +74,8 @@ func Test_Reader_readID(t *testing.T) {
 			setTestEnv(t, key, testCase.keyValue)
 			setTestEnv(t, retroKey, testCase.retroValue)

-			source := &Source{}
-			id, err := source.readID(key, retroKey)
+			reader := &Reader{}
+			id, err := reader.readID(key, retroKey)

 			assert.ErrorIs(t, err, testCase.errWrapped)
 			if err != nil {
--- a/internal/configuration/sources/env/vpn.go
+++ b/internal/configuration/sources/env/vpn.go
@@ -7,20 +7,20 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readVPN() (vpn settings.VPN, err error) {
+func (r *Reader) readVPN() (vpn settings.VPN, err error) {
 	vpn.Type = strings.ToLower(getCleanedEnv("VPN_TYPE"))

-	vpn.Provider, err = s.readProvider(vpn.Type)
+	vpn.Provider, err = r.readProvider(vpn.Type)
 	if err != nil {
 		return vpn, fmt.Errorf("VPN provider: %w", err)
 	}

-	vpn.OpenVPN, err = s.readOpenVPN()
+	vpn.OpenVPN, err = r.readOpenVPN()
 	if err != nil {
 		return vpn, fmt.Errorf("OpenVPN: %w", err)
 	}

-	vpn.Wireguard, err = s.readWireguard()
+	vpn.Wireguard, err = r.readWireguard()
 	if err != nil {
 		return vpn, fmt.Errorf("wireguard: %w", err)
 	}
--- a/internal/configuration/sources/env/wireguard.go
+++ b/internal/configuration/sources/env/wireguard.go
@@ -3,29 +3,27 @@ package env
 import (
 	"fmt"
 	"net"
-	"os"
 	"strings"

 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readWireguard() (wireguard settings.Wireguard, err error) {
+func (r *Reader) readWireguard() (wireguard settings.Wireguard, err error) {
 	defer func() {
 		err = unsetEnvKeys([]string{"WIREGUARD_PRIVATE_KEY", "WIREGUARD_PRESHARED_KEY"}, err)
 	}()
 	wireguard.PrivateKey = envToStringPtr("WIREGUARD_PRIVATE_KEY")
 	wireguard.PreSharedKey = envToStringPtr("WIREGUARD_PRESHARED_KEY")
-	_, wireguard.Interface = s.getEnvWithRetro("VPN_INTERFACE", "WIREGUARD_INTERFACE")
-	wireguard.Implementation = os.Getenv("WIREGUARD_IMPLEMENTATION")
-	wireguard.Addresses, err = s.readWireguardAddresses()
+	_, wireguard.Interface = r.getEnvWithRetro("VPN_INTERFACE", "WIREGUARD_INTERFACE")
+	wireguard.Addresses, err = r.readWireguardAddresses()
 	if err != nil {
 		return wireguard, err // already wrapped
 	}
 	return wireguard, nil
 }

-func (s *Source) readWireguardAddresses() (addresses []net.IPNet, err error) {
-	key, addressesCSV := s.getEnvWithRetro("WIREGUARD_ADDRESSES", "WIREGUARD_ADDRESS")
+func (r *Reader) readWireguardAddresses() (addresses []net.IPNet, err error) {
+	key, addressesCSV := r.getEnvWithRetro("WIREGUARD_ADDRESSES", "WIREGUARD_ADDRESS")
 	if addressesCSV == "" {
 		return nil, nil
 	}
@@ -33,7 +31,6 @@ func (s *Source) readWireguardAddresses() (addresses []net.IPNet, err error) {
 	addressStrings := strings.Split(addressesCSV, ",")
 	addresses = make([]net.IPNet, len(addressStrings))
 	for i, addressString := range addressStrings {
-		addressString = strings.TrimSpace(addressString)
 		ip, ipNet, err := net.ParseCIDR(addressString)
 		if err != nil {
 			return nil, fmt.Errorf("environment variable %s: %w", key, err)
--- a/internal/configuration/sources/env/wireguardselection.go
+++ b/internal/configuration/sources/env/wireguardselection.go
@@ -9,14 +9,14 @@ import (
 	"github.com/qdm12/govalid/port"
 )

-func (s *Source) readWireguardSelection() (
+func (r *Reader) readWireguardSelection() (
 	selection settings.WireguardSelection, err error) {
-	selection.EndpointIP, err = s.readWireguardEndpointIP()
+	selection.EndpointIP, err = r.readWireguardEndpointIP()
 	if err != nil {
 		return selection, err
 	}

-	selection.EndpointPort, err = s.readWireguardCustomPort()
+	selection.EndpointPort, err = r.readWireguardCustomPort()
 	if err != nil {
 		return selection, err
 	}
@@ -28,29 +28,29 @@ func (s *Source) readWireguardSelection() (

 var ErrIPAddressParse = errors.New("cannot parse IP address")

-func (s *Source) readWireguardEndpointIP() (endpointIP net.IP, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_IP", "WIREGUARD_ENDPOINT_IP")
-	if value == "" {
+func (r *Reader) readWireguardEndpointIP() (endpointIP net.IP, err error) {
+	key, s := r.getEnvWithRetro("VPN_ENDPOINT_IP", "WIREGUARD_ENDPOINT_IP")
+	if s == "" {
 		return nil, nil
 	}

-	endpointIP = net.ParseIP(value)
+	endpointIP = net.ParseIP(s)
 	if endpointIP == nil {
 		return nil, fmt.Errorf("environment variable %s: %w: %s",
-			key, ErrIPAddressParse, value)
+			key, ErrIPAddressParse, s)
 	}

 	return endpointIP, nil
 }

-func (s *Source) readWireguardCustomPort() (customPort *uint16, err error) {
-	key, value := s.getEnvWithRetro("VPN_ENDPOINT_PORT", "WIREGUARD_ENDPOINT_PORT")
-	if value == "" {
+func (r *Reader) readWireguardCustomPort() (customPort *uint16, err error) {
+	key, s := r.getEnvWithRetro("VPN_ENDPOINT_PORT", "WIREGUARD_ENDPOINT_PORT")
+	if s == "" {
 		return nil, nil //nolint:nilnil
 	}

 	customPort = new(uint16)
-	*customPort, err = port.Validate(value)
+	*customPort, err = port.Validate(s)
 	if err != nil {
 		return nil, fmt.Errorf("environment variable %s: %w", key, err)
 	}
--- a/internal/configuration/sources/files/health.go
+++ b/internal/configuration/sources/files/health.go
@@ -2,4 +2,4 @@ package files

 import "github.com/qdm12/gluetun/internal/configuration/settings"

-func (s *Source) ReadHealth() (settings settings.Health, err error) { return settings, nil }
+func (r *Reader) ReadHealth() (settings settings.Health, err error) { return settings, nil }
--- a/internal/configuration/sources/files/openvpn.go
+++ b/internal/configuration/sources/files/openvpn.go
@@ -11,23 +11,18 @@ const (
 	OpenVPNClientKeyPath = "/gluetun/client.key"
 	// OpenVPNClientCertificatePath is the OpenVPN client certificate filepath.
 	OpenVPNClientCertificatePath = "/gluetun/client.crt"
-	openVPNEncryptedKey          = "/gluetun/openvpn_encrypted_key"
 )

-func (s *Source) readOpenVPN() (settings settings.OpenVPN, err error) {
-	settings.Key, err = readPEMFile(OpenVPNClientKeyPath)
+func (r *Reader) readOpenVPN() (settings settings.OpenVPN, err error) {
+	settings.ClientKey, err = readPEMFile(OpenVPNClientKeyPath)
 	if err != nil {
 		return settings, fmt.Errorf("client key: %w", err)
 	}

-	settings.Cert, err = readPEMFile(OpenVPNClientCertificatePath)
+	settings.ClientCrt, err = readPEMFile(OpenVPNClientCertificatePath)
 	if err != nil {
 		return settings, fmt.Errorf("client certificate: %w", err)
 	}
-	settings.EncryptedKey, err = readPEMFile(openVPNEncryptedKey)
-	if err != nil {
-		return settings, fmt.Errorf("reading encrypted key file: %w", err)
-	}

 	return settings, nil
 }
--- a/internal/configuration/sources/files/reader.go
+++ b/internal/configuration/sources/files/reader.go
@@ -2,23 +2,26 @@ package files

 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/configuration/sources"
 )

-type Source struct{}
+var _ sources.Source = (*Reader)(nil)

-func New() *Source {
-	return &Source{}
+type Reader struct{}
+
+func New() *Reader {
+	return &Reader{}
 }

-func (s *Source) String() string { return "files" }
+func (r *Reader) String() string { return "files" }

-func (s *Source) Read() (settings settings.Settings, err error) {
-	settings.VPN, err = s.readVPN()
+func (r *Reader) Read() (settings settings.Settings, err error) {
+	settings.VPN, err = r.readVPN()
 	if err != nil {
 		return settings, err
 	}

-	settings.System, err = s.readSystem()
+	settings.System, err = r.readSystem()
 	if err != nil {
 		return settings, err
 	}
--- a/internal/configuration/sources/files/system.go
+++ b/internal/configuration/sources/files/system.go
@@ -4,7 +4,7 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readSystem() (system settings.System, err error) {
+func (r *Reader) readSystem() (system settings.System, err error) {
 	// TODO timezone from /etc/localtime
 	return system, nil
 }
--- a/internal/configuration/sources/files/vpn.go
+++ b/internal/configuration/sources/files/vpn.go
@@ -6,8 +6,8 @@ import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 )

-func (s *Source) readVPN() (vpn settings.VPN, err error) {
-	vpn.OpenVPN, err = s.readOpenVPN()
+func (r *Reader) readVPN() (vpn settings.VPN, err error) {
+	vpn.OpenVPN, err = r.readOpenVPN()
 	if err != nil {
 		return vpn, fmt.Errorf("OpenVPN: %w", err)
 	}
--- a/internal/configuration/sources/merge/reader.go
+++ b/internal/configuration/sources/merge/reader.go
@@ -1,32 +1,29 @@
-package merge
+package mux

 import (
 	"fmt"
 	"strings"

 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/configuration/sources"
 )

-type ConfigSource interface {
-	Read() (settings settings.Settings, err error)
-	ReadHealth() (settings settings.Health, err error)
-	String() string
+var _ sources.Source = (*Reader)(nil)
+
+type Reader struct {
+	sources []sources.Source
 }

-type Source struct {
-	sources []ConfigSource
-}
-
-func New(sources ...ConfigSource) *Source {
-	return &Source{
+func New(sources ...sources.Source) *Reader {
+	return &Reader{
 		sources: sources,
 	}
 }

-func (s *Source) String() string {
-	sources := make([]string, len(s.sources))
-	for i := range s.sources {
-		sources[i] = s.sources[i].String()
+func (r *Reader) String() string {
+	sources := make([]string, len(r.sources))
+	for i := range r.sources {
+		sources[i] = r.sources[i].String()
 	}
 	return strings.Join(sources, ", ")
 }
@@ -34,8 +31,8 @@ func (s *Source) String() string {
 // Read reads the settings for each source, merging unset fields
 // with field set by the next source.
 // It then set defaults to remaining unset fields.
-func (s *Source) Read() (settings settings.Settings, err error) {
-	for _, source := range s.sources {
+func (r *Reader) Read() (settings settings.Settings, err error) {
+	for _, source := range r.sources {
 		settingsFromSource, err := source.Read()
 		if err != nil {
 			return settings, fmt.Errorf("reading from %s: %w", source, err)
@@ -50,8 +47,8 @@ func (s *Source) Read() (settings settings.Settings, err error) {
 // with field set by the next source.
 // It then set defaults to remaining unset fields, and validate
 // all the fields.
-func (s *Source) ReadHealth() (settings settings.Health, err error) {
-	for _, source := range s.sources {
+func (r *Reader) ReadHealth() (settings settings.Health, err error) {
+	for _, source := range r.sources {
 		settingsFromSource, err := source.ReadHealth()
 		if err != nil {
 			return settings, fmt.Errorf("reading from %s: %w", source, err)
--- a/internal/configuration/sources/secrets/health.go
+++ b/internal/configuration/sources/secrets/health.go
@@ -2,4 +2,4 @@ package secrets

 import "github.com/qdm12/gluetun/internal/configuration/settings"

-func (s *Source) ReadHealth() (settings settings.Health, err error) { return settings, nil }
+func (r *Reader) ReadHealth() (settings settings.Health, err error) { return settings, nil }
--- a/internal/configuration/sources/secrets/helpers.go
+++ b/internal/configuration/sources/secrets/helpers.go
@@ -28,6 +28,21 @@ func readSecretFileAsStringPtr(secretPathEnvKey, defaultSecretPath string) (
 	return files.ReadFromFile(path)
 }

+func readSecretFileAsString(secretPathEnvKey, defaultSecretPath string) (
+	s string, err error) {
+	path := getCleanedEnv(secretPathEnvKey)
+	if path == "" {
+		path = defaultSecretPath
+	}
+	stringPtr, err := files.ReadFromFile(path)
+	if err != nil {
+		return "", err
+	} else if stringPtr == nil {
+		return "", nil
+	}
+	return *stringPtr, nil
+}
+
 func readPEMSecretFile(secretPathEnvKey, defaultSecretPath string) (
 	base64Ptr *string, err error) {
 	pemData, err := readSecretFileAsStringPtr(secretPathEnvKey, defaultSecretPath)
--- a/internal/configuration/sources/secrets/httpproxy.go
+++ b/internal/configuration/sources/secrets/httpproxy.go
@@ -12,7 +12,7 @@ func readHTTPProxy() (settings settings.HTTPProxy, err error) {
 		"/run/secrets/httpproxy_user",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading HTTP proxy user secret file: %w", err)
+		return settings, fmt.Errorf("cannot read HTTP proxy user secret file: %w", err)
 	}

 	settings.Password, err = readSecretFileAsStringPtr(
@@ -20,7 +20,7 @@ func readHTTPProxy() (settings settings.HTTPProxy, err error) {
 		"/run/secrets/httpproxy_password",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading OpenVPN password secret file: %w", err)
+		return settings, fmt.Errorf("cannot read OpenVPN password secret file: %w", err)
 	}

 	return settings, nil
--- a/internal/configuration/sources/secrets/openvpn.go
+++ b/internal/configuration/sources/secrets/openvpn.go
@@ -8,52 +8,36 @@ import (

 func readOpenVPN() (
 	settings settings.OpenVPN, err error) {
-	settings.User, err = readSecretFileAsStringPtr(
+	settings.User, err = readSecretFileAsString(
 		"OPENVPN_USER_SECRETFILE",
 		"/run/secrets/openvpn_user",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading user file: %w", err)
+		return settings, fmt.Errorf("cannot read user file: %w", err)
 	}

-	settings.Password, err = readSecretFileAsStringPtr(
+	settings.Password, err = readSecretFileAsString(
 		"OPENVPN_PASSWORD_SECRETFILE",
 		"/run/secrets/openvpn_password",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading password file: %w", err)
+		return settings, fmt.Errorf("cannot read password file: %w", err)
 	}

-	settings.Key, err = readPEMSecretFile(
+	settings.ClientKey, err = readPEMSecretFile(
 		"OPENVPN_CLIENTKEY_SECRETFILE",
 		"/run/secrets/openvpn_clientkey",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading client key file: %w", err)
+		return settings, fmt.Errorf("cannot read client key file: %w", err)
 	}

-	settings.EncryptedKey, err = readPEMSecretFile(
-		"OPENVPN_ENCRYPTED_KEY_SECRETFILE",
-		"/run/secrets/openvpn_encrypted_key",
-	)
-	if err != nil {
-		return settings, fmt.Errorf("reading encrypted key file: %w", err)
-	}
-
-	settings.KeyPassphrase, err = readSecretFileAsStringPtr(
-		"OPENVPN_KEY_PASSPHRASE_SECRETFILE",
-		"/run/secrets/openvpn_key_passphrase",
-	)
-	if err != nil {
-		return settings, fmt.Errorf("reading key passphrase file: %w", err)
-	}
-
-	settings.Cert, err = readPEMSecretFile(
+	settings.ClientCrt, err = readPEMSecretFile(
 		"OPENVPN_CLIENTCRT_SECRETFILE",
 		"/run/secrets/openvpn_clientcrt",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading client certificate file: %w", err)
+		return settings, fmt.Errorf("cannot read client certificate file: %w", err)
 	}

 	return settings, nil
--- a/internal/configuration/sources/secrets/reader.go
+++ b/internal/configuration/sources/secrets/reader.go
@@ -2,17 +2,21 @@ package secrets

 import (
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/configuration/sources"
 )

-type Source struct{}
+var _ sources.Source = (*Reader)(nil)

-func New() *Source {
-	return &Source{}
+type Reader struct {
 }

-func (s *Source) String() string { return "secret files" }
+func New() *Reader {
+	return &Reader{}
+}

-func (s *Source) Read() (settings settings.Settings, err error) {
+func (r *Reader) String() string { return "secret files" }
+
+func (r *Reader) Read() (settings settings.Settings, err error) {
 	settings.VPN, err = readVPN()
 	if err != nil {
 		return settings, err
--- a/internal/configuration/sources/secrets/shadowsocks.go
+++ b/internal/configuration/sources/secrets/shadowsocks.go
@@ -12,7 +12,7 @@ func readShadowsocks() (settings settings.Shadowsocks, err error) {
 		"/run/secrets/shadowsocks_password",
 	)
 	if err != nil {
-		return settings, fmt.Errorf("reading Shadowsocks password secret file: %w", err)
+		return settings, fmt.Errorf("cannot read Shadowsocks password secret file: %w", err)
 	}

 	return settings, nil
--- a/internal/configuration/sources/secrets/vpn.go
+++ b/internal/configuration/sources/secrets/vpn.go
@@ -9,7 +9,7 @@ import (
 func readVPN() (vpn settings.VPN, err error) {
 	vpn.OpenVPN, err = readOpenVPN()
 	if err != nil {
-		return vpn, fmt.Errorf("reading OpenVPN settings: %w", err)
+		return vpn, fmt.Errorf("cannot read OpenVPN settings: %w", err)
 	}

 	return vpn, nil
--- a/internal/configuration/sources/source.go
+++ b/internal/configuration/sources/source.go
@@ -1,9 +1,9 @@
-package cli
+package sources

 import "github.com/qdm12/gluetun/internal/configuration/settings"

 type Source interface {
 	Read() (settings settings.Settings, err error)
-	ReadHealth() (health settings.Health, err error)
+	ReadHealth() (settings settings.Health, err error)
 	String() string
 }
--- a/internal/constants/openvpn/ciphers.go
+++ b/internal/constants/openvpn/ciphers.go
@@ -1,11 +1,8 @@
 package openvpn

 const (
-	AES128cbc        = "aes-128-cbc"
-	AES192cbc        = "aes-192-cbc"
-	AES256cbc        = "aes-256-cbc"
-	AES128gcm        = "aes-128-gcm"
-	AES192gcm        = "aes-192-gcm"
-	AES256gcm        = "aes-256-gcm"
-	Chacha20Poly1305 = "chacha20-poly1305"
+	AES128cbc = "aes-128-cbc"
+	AES256cbc = "aes-256-cbc"
+	AES128gcm = "aes-128-gcm"
+	AES256gcm = "aes-256-gcm"
 )
--- a/internal/constants/openvpn/paths.go
+++ b/internal/constants/openvpn/paths.go
@@ -3,7 +3,4 @@ package openvpn
 const (
 	// AuthConf is the file path to the OpenVPN auth file.
 	AuthConf = "/etc/openvpn/auth.conf"
-	// AskPassPath is the file path to the decryption passphrase for
-	// and encrypted private key, which is pointed by `askpass`.
-	AskPassPath = "/etc/openvpn/askpass" //nolint:gosec
 )
--- a/internal/constants/providers/providers.go
+++ b/internal/constants/providers/providers.go
@@ -3,7 +3,6 @@ package providers
 const (
 	// Custom is the VPN provider name for custom
 	// VPN configurations.
-	Airvpn                = "airvpn"
 	Custom                = "custom"
 	Cyberghost            = "cyberghost"
 	Example               = "example"
@@ -20,10 +19,8 @@ const (
 	Privatevpn            = "privatevpn"
 	Protonvpn             = "protonvpn"
 	Purevpn               = "purevpn"
-	SlickVPN              = "slickvpn"
 	Surfshark             = "surfshark"
 	Torguard              = "torguard"
-	VPNSecure             = "vpnsecure"
 	VPNUnlimited          = "vpn unlimited"
 	Vyprvpn               = "vyprvpn"
 	Wevpn                 = "wevpn"
@@ -33,7 +30,6 @@ const (
 // All returns all the providers except the custom provider.
 func All() []string {
 	return []string{
-		Airvpn,
 		Cyberghost,
 		Expressvpn,
 		Fastestvpn,
@@ -48,10 +44,8 @@ func All() []string {
 		Privatevpn,
 		Protonvpn,
 		Purevpn,
-		SlickVPN,
 		Surfshark,
 		Torguard,
-		VPNSecure,
 		VPNUnlimited,
 		Vyprvpn,
 		Wevpn,
--- a/internal/firewall/cmd_matcher_test.go
+++ b/internal/firewall/cmd_matcher_test.go
@@ -48,7 +48,7 @@ func (cm *cmdMatcher) String() string {
 	return fmt.Sprintf("path %s, argument regular expressions %v", cm.path, cm.argsRegex)
 }

-func newCmdMatcher(path string, argsRegex ...string) *cmdMatcher {
+func newCmdMatcher(path string, argsRegex ...string) *cmdMatcher { //nolint:unparam
 	argsRegexp := make([]*regexp.Regexp, len(argsRegex))
 	for i, argRegex := range argsRegex {
 		argsRegexp[i] = regexp.MustCompile(argRegex)
--- a/internal/firewall/enable.go
+++ b/internal/firewall/enable.go
@@ -21,7 +21,7 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {
 	if !enabled {
 		c.logger.Info("disabling...")
 		if err = c.disable(ctx); err != nil {
-			return fmt.Errorf("disabling firewall: %w", err)
+			return fmt.Errorf("cannot disable firewall: %w", err)
 		}
 		c.enabled = false
 		c.logger.Info("disabled successfully")
@@ -31,7 +31,7 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {
 	c.logger.Info("enabling...")

 	if err := c.enable(ctx); err != nil {
-		return fmt.Errorf("enabling firewall: %w", err)
+		return fmt.Errorf("cannot enable firewall: %w", err)
 	}
 	c.enabled = true
 	c.logger.Info("enabled successfully")
@@ -41,13 +41,13 @@ func (c *Config) SetEnabled(ctx context.Context, enabled bool) (err error) {

 func (c *Config) disable(ctx context.Context) (err error) {
 	if err = c.clearAllRules(ctx); err != nil {
-		return fmt.Errorf("clearing all rules: %w", err)
+		return fmt.Errorf("cannot clear all rules: %w", err)
 	}
 	if err = c.setIPv4AllPolicies(ctx, "ACCEPT"); err != nil {
-		return fmt.Errorf("setting ipv4 policies: %w", err)
+		return fmt.Errorf("cannot set ipv4 policies: %w", err)
 	}
 	if err = c.setIPv6AllPolicies(ctx, "ACCEPT"); err != nil {
-		return fmt.Errorf("setting ipv6 policies: %w", err)
+		return fmt.Errorf("cannot set ipv6 policies: %w", err)
 	}
 	return nil
 }
@@ -101,9 +101,6 @@ func (c *Config) enable(ctx context.Context) (err error) {
 		if err := c.acceptOutputFromIPToSubnet(ctx, network.InterfaceName, network.IP, *network.IPNet, remove); err != nil {
 			return err
 		}
-		if err = c.acceptIpv6MulticastOutput(ctx, network.InterfaceName, remove); err != nil {
-			return err
-		}
 	}

 	if err = c.allowOutboundSubnets(ctx); err != nil {
@@ -123,7 +120,7 @@ func (c *Config) enable(ctx context.Context) (err error) {
 	}

 	if err := c.runUserPostRules(ctx, c.customRulesPath, remove); err != nil {
-		return fmt.Errorf("running user defined post firewall rules: %w", err)
+		return fmt.Errorf("cannot run user defined post firewall rules: %w", err)
 	}

 	return nil
@@ -138,7 +135,7 @@ func (c *Config) allowVPNIP(ctx context.Context) (err error) {
 	for _, defaultRoute := range c.defaultRoutes {
 		err = c.acceptOutputTrafficToVPN(ctx, defaultRoute.NetInterface, c.vpnConnection, remove)
 		if err != nil {
-			return fmt.Errorf("accepting output traffic through VPN: %w", err)
+			return fmt.Errorf("cannot accept output traffic through VPN: %w", err)
 		}
 	}

@@ -165,7 +162,7 @@ func (c *Config) allowInputPorts(ctx context.Context) (err error) {
 			const remove = false
 			err = c.acceptInputToPort(ctx, netInterface, port, remove)
 			if err != nil {
-				return fmt.Errorf("accepting input port %d on interface %s: %w",
+				return fmt.Errorf("cannot accept input port %d on interface %s: %w",
 					port, netInterface, err)
 			}
 		}
--- a/internal/firewall/iptables.go
+++ b/internal/firewall/iptables.go
@@ -179,18 +179,6 @@ func (c *Config) acceptOutputFromIPToSubnet(ctx context.Context,
 	return c.runIP6tablesInstruction(ctx, instruction)
 }

-// NDP uses multicast address (theres no broadcast in IPv6 like ARP uses in IPv4).
-func (c *Config) acceptIpv6MulticastOutput(ctx context.Context,
-	intf string, remove bool) error {
-	interfaceFlag := "-o " + intf
-	if intf == "*" { // all interfaces
-		interfaceFlag = ""
-	}
-	instruction := fmt.Sprintf("%s OUTPUT %s -d ff02::1:ff/104 -j ACCEPT",
-		appendOrDelete(remove), interfaceFlag)
-	return c.runIP6tablesInstruction(ctx, instruction)
-}
-
 // Used for port forwarding, with intf set to tun.
 func (c *Config) acceptInputToPort(ctx context.Context, intf string, port uint16, remove bool) error {
 	interfaceFlag := "-i " + intf
@@ -257,7 +245,7 @@ func (c *Config) runUserPostRules(ctx context.Context, filepath string, remove b
 		case ipv4:
 			err = c.runIptablesInstruction(ctx, rule)
 		case c.ip6Tables == "":
-			err = fmt.Errorf("running user ip6tables rule: %w", ErrNeedIP6Tables)
+			err = fmt.Errorf("cannot run user ip6tables rule: %w", ErrNeedIP6Tables)
 		default: // ipv6
 			err = c.runIP6tablesInstruction(ctx, rule)
 		}
--- a/internal/firewall/outboundsubnets.go
+++ b/internal/firewall/outboundsubnets.go
@@ -28,7 +28,7 @@ func (c *Config) SetOutboundSubnets(ctx context.Context, subnets []net.IPNet) (e

 	c.removeOutboundSubnets(ctx, subnetsToRemove)
 	if err := c.addOutboundSubnets(ctx, subnetsToAdd); err != nil {
-		return fmt.Errorf("setting allowed outbound subnets: %w", err)
+		return fmt.Errorf("cannot set allowed outbound subnets: %w", err)
 	}

 	return nil
--- a/internal/firewall/ports.go
+++ b/internal/firewall/ports.go
@@ -36,11 +36,10 @@ func (c *Config) SetAllowedPort(ctx context.Context, port uint16, intf string) (

 	const remove = false
 	if err := c.acceptInputToPort(ctx, intf, port, remove); err != nil {
-		return fmt.Errorf("allowing input to port %d through interface %s: %w",
+		return fmt.Errorf("cannot allow input to port %d through interface %s: %w",
 			port, intf, err)
 	}
 	netInterfaces[intf] = struct{}{}
-	c.allowedInputPorts[port] = netInterfaces

 	return nil
 }
@@ -70,7 +69,7 @@ func (c *Config) RemoveAllowedPort(ctx context.Context, port uint16) (err error)
 	for netInterface := range interfacesSet {
 		err := c.acceptInputToPort(ctx, netInterface, port, remove)
 		if err != nil {
-			return fmt.Errorf("removing allowed port %d on interface %s: %w",
+			return fmt.Errorf("cannot remove allowed port %d on interface %s: %w",
 				port, netInterface, err)
 		}
 		delete(interfacesSet, netInterface)
--- a/internal/firewall/support.go
+++ b/internal/firewall/support.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"math/rand"
 	"os/exec"
-	"sort"
 	"strings"

 	"github.com/qdm12/golibs/command"
@@ -21,7 +20,7 @@ var (

 func checkIptablesSupport(ctx context.Context, runner command.Runner,
 	iptablesPathsToTry ...string) (iptablesPath string, err error) {
-	iptablesPathToUnsupportedMessage := make(map[string]string, len(iptablesPathsToTry))
+	var lastUnsupportedMessage string
 	for _, pathToTest := range iptablesPathsToTry {
 		ok, unsupportedMessage, err := testIptablesPath(ctx, pathToTest, runner)
 		if err != nil {
@@ -30,35 +29,17 @@ func checkIptablesSupport(ctx context.Context, runner command.Runner,
 			iptablesPath = pathToTest
 			break
 		}
-		iptablesPathToUnsupportedMessage[pathToTest] = unsupportedMessage
+
+		lastUnsupportedMessage = unsupportedMessage
 	}

-	if iptablesPath != "" {
-		// some paths may be unsupported but that does not matter
-		// since we found one working.
-		return iptablesPath, nil
+	if iptablesPath == "" { // all iptables to try failed
+		return "", fmt.Errorf("%w: from %s: last error is: %s",
+			ErrIPTablesNotSupported, strings.Join(iptablesPathsToTry, ", "),
+			lastUnsupportedMessage)
 	}

-	allArePermissionDenied := true
-	allUnsupportedMessages := make(sort.StringSlice, 0, len(iptablesPathToUnsupportedMessage))
-	for iptablesPath, unsupportedMessage := range iptablesPathToUnsupportedMessage {
-		if !isPermissionDenied(unsupportedMessage) {
-			allArePermissionDenied = false
-		}
-		unsupportedMessage = iptablesPath + ": " + unsupportedMessage
-		allUnsupportedMessages = append(allUnsupportedMessages, unsupportedMessage)
-	}
-
-	allUnsupportedMessages.Sort() // predictable order for tests
-
-	if allArePermissionDenied {
-		// If the error is related to a denied permission for all iptables path,
-		// return an error describing what to do from an end-user perspective.
-		return "", fmt.Errorf("%w: %s", ErrNetAdminMissing, strings.Join(allUnsupportedMessages, "; "))
-	}
-
-	return "", fmt.Errorf("%w: errors encountered are: %s",
-		ErrIPTablesNotSupported, strings.Join(allUnsupportedMessages, "; "))
+	return iptablesPath, nil
 }

 func testIptablesPath(ctx context.Context, path string,
@@ -75,6 +56,14 @@ func testIptablesPath(ctx context.Context, path string,
 		"-A", "OUTPUT", "-o", testInterfaceName, "-j", "DROP")
 	output, err := runner.Run(cmd)
 	if err != nil {
+		if isPermissionDenied(output) {
+			// If the error is related to a denied permission,
+			// return an error describing what to do from an end-user
+			// perspective. This is a critical error and likely
+			// applies to all iptables.
+			criticalErr = fmt.Errorf("%w: %s", ErrNetAdminMissing, output)
+			return false, "", criticalErr
+		}
 		unsupportedMessage = fmt.Sprintf("%s (%s)", output, err)
 		return false, unsupportedMessage, nil
 	}
@@ -95,6 +84,10 @@ func testIptablesPath(ctx context.Context, path string,
 	cmd = exec.CommandContext(ctx, path, "-L", "INPUT")
 	output, err = runner.Run(cmd)
 	if err != nil {
+		if isPermissionDenied(output) {
+			criticalErr = fmt.Errorf("%w: %s", ErrNetAdminMissing, output)
+			return false, "", criticalErr
+		}
 		unsupportedMessage = fmt.Sprintf("%s (%s)", output, err)
 		return false, unsupportedMessage, nil
 	}
@@ -116,6 +109,10 @@ func testIptablesPath(ctx context.Context, path string,
 	cmd = exec.CommandContext(ctx, path, "--policy", "INPUT", inputPolicy)
 	output, err = runner.Run(cmd)
 	if err != nil {
+		if isPermissionDenied(output) {
+			criticalErr = fmt.Errorf("%w: %s", ErrNetAdminMissing, output)
+			return false, "", criticalErr
+		}
 		unsupportedMessage = fmt.Sprintf("%s (%s)", output, err)
 		return false, unsupportedMessage, nil
 	}
--- a/internal/firewall/support_test.go
+++ b/internal/firewall/support_test.go
@@ -8,130 +8,10 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/qdm12/golibs/command"
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )

 //go:generate mockgen -destination=runner_mock_test.go -package $GOPACKAGE github.com/qdm12/golibs/command Runner

-func newAppendTestRuleMatcher(path string) *cmdMatcher {
-	return newCmdMatcher(path,
-		"^-A$", "^OUTPUT$", "^-o$", "^[a-z0-9]{15}$",
-		"^-j$", "^DROP$")
-}
-
-func newDeleteTestRuleMatcher(path string) *cmdMatcher {
-	return newCmdMatcher(path,
-		"^-D$", "^OUTPUT$", "^-o$", "^[a-z0-9]{15}$",
-		"^-j$", "^DROP$")
-}
-
-func newListInputRulesMatcher(path string) *cmdMatcher {
-	return newCmdMatcher(path,
-		"^-L$", "^INPUT$")
-}
-
-func newSetPolicyMatcher(path, inputPolicy string) *cmdMatcher { //nolint:unparam
-	return newCmdMatcher(path,
-		"^--policy$", "^INPUT$", "^"+inputPolicy+"$")
-}
-
-func Test_checkIptablesSupport(t *testing.T) {
-	t.Parallel()
-
-	ctx := context.Background()
-	errDummy := errors.New("exit code 4")
-	const inputPolicy = "ACCEPT"
-
-	testCases := map[string]struct {
-		buildRunner        func(ctrl *gomock.Controller) command.Runner
-		iptablesPathsToTry []string
-		iptablesPath       string
-		errSentinel        error
-		errMessage         string
-	}{
-		"critical error when checking": {
-			buildRunner: func(ctrl *gomock.Controller) command.Runner {
-				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path1")).
-					Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher("path1")).
-					Return("output", errDummy)
-				return runner
-			},
-			iptablesPathsToTry: []string{"path1", "path2"},
-			errSentinel:        ErrTestRuleCleanup,
-			errMessage: "for path1: failed cleaning up test rule: " +
-				"output (exit code 4)",
-		},
-		"found valid path": {
-			buildRunner: func(ctrl *gomock.Controller) command.Runner {
-				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path1")).
-					Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher("path1")).
-					Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher("path1")).
-					Return("Chain INPUT (policy "+inputPolicy+")", nil)
-				runner.EXPECT().Run(newSetPolicyMatcher("path1", inputPolicy)).
-					Return("", nil)
-				return runner
-			},
-			iptablesPathsToTry: []string{"path1", "path2"},
-			iptablesPath:       "path1",
-		},
-		"all permission denied": {
-			buildRunner: func(ctrl *gomock.Controller) command.Runner {
-				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path1")).
-					Return("Permission denied (you must be root) more context", errDummy)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path2")).
-					Return("context: Permission denied (you must be root)", errDummy)
-				return runner
-			},
-			iptablesPathsToTry: []string{"path1", "path2"},
-			errSentinel:        ErrNetAdminMissing,
-			errMessage: "NET_ADMIN capability is missing: " +
-				"path1: Permission denied (you must be root) more context (exit code 4); " +
-				"path2: context: Permission denied (you must be root) (exit code 4)",
-		},
-		"no valid path": {
-			buildRunner: func(ctrl *gomock.Controller) command.Runner {
-				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path1")).
-					Return("output 1", errDummy)
-				runner.EXPECT().Run(newAppendTestRuleMatcher("path2")).
-					Return("output 2", errDummy)
-				return runner
-			},
-			iptablesPathsToTry: []string{"path1", "path2"},
-			errSentinel:        ErrIPTablesNotSupported,
-			errMessage: "no iptables supported found: " +
-				"errors encountered are: " +
-				"path1: output 1 (exit code 4); " +
-				"path2: output 2 (exit code 4)",
-		},
-	}
-
-	for name, testCase := range testCases {
-		testCase := testCase
-		t.Run(name, func(t *testing.T) {
-			t.Parallel()
-			ctrl := gomock.NewController(t)
-
-			runner := testCase.buildRunner(ctrl)
-
-			iptablesPath, err :=
-				checkIptablesSupport(ctx, runner, testCase.iptablesPathsToTry...)
-
-			require.ErrorIs(t, err, testCase.errSentinel)
-			if testCase.errSentinel != nil {
-				assert.EqualError(t, err, testCase.errMessage)
-			}
-			assert.Equal(t, testCase.iptablesPath, iptablesPath)
-		})
-	}
-}
-
 func Test_testIptablesPath(t *testing.T) {
 	t.Parallel()

@@ -140,6 +20,17 @@ func Test_testIptablesPath(t *testing.T) {
 	errDummy := errors.New("exit code 4")
 	const inputPolicy = "ACCEPT"

+	appendTestRuleMatcher := newCmdMatcher(path,
+		"^-A$", "^OUTPUT$", "^-o$", "^[a-z0-9]{15}$",
+		"^-j$", "^DROP$")
+	deleteTestRuleMatcher := newCmdMatcher(path,
+		"^-D$", "^OUTPUT$", "^-o$", "^[a-z0-9]{15}$",
+		"^-j$", "^DROP$")
+	listInputRulesMatcher := newCmdMatcher(path,
+		"^-L$", "^INPUT$")
+	setPolicyMatcher := newCmdMatcher(path,
+		"^--policy$", "^INPUT$", "^"+inputPolicy+"$")
+
 	testCases := map[string]struct {
 		buildRunner        func(ctrl *gomock.Controller) command.Runner
 		ok                 bool
@@ -150,16 +41,18 @@ func Test_testIptablesPath(t *testing.T) {
 		"append test rule permission denied": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).
 					Return("Permission denied (you must be root)", errDummy)
 				return runner
 			},
-			unsupportedMessage: "Permission denied (you must be root) (exit code 4)",
+			criticalErrWrapped: ErrNetAdminMissing,
+			criticalErrMessage: "NET_ADMIN capability is missing: " +
+				"Permission denied (you must be root)",
 		},
 		"append test rule unsupported": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).
 					Return("some output", errDummy)
 				return runner
 			},
@@ -168,8 +61,8 @@ func Test_testIptablesPath(t *testing.T) {
 		"remove test rule error": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).
 					Return("some output", errDummy)
 				return runner
 			},
@@ -179,20 +72,22 @@ func Test_testIptablesPath(t *testing.T) {
 		"list input rules permission denied": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("Permission denied (you must be root)", errDummy)
 				return runner
 			},
-			unsupportedMessage: "Permission denied (you must be root) (exit code 4)",
+			criticalErrWrapped: ErrNetAdminMissing,
+			criticalErrMessage: "NET_ADMIN capability is missing: " +
+				"Permission denied (you must be root)",
 		},
 		"list input rules unsupported": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("some output", errDummy)
 				return runner
 			},
@@ -201,9 +96,9 @@ func Test_testIptablesPath(t *testing.T) {
 		"list input rules no policy": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("some\noutput", nil)
 				return runner
 			},
@@ -213,24 +108,26 @@ func Test_testIptablesPath(t *testing.T) {
 		"set policy permission denied": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("\nChain INPUT (policy "+inputPolicy+")\nxx\n", nil)
-				runner.EXPECT().Run(newSetPolicyMatcher(path, inputPolicy)).
+				runner.EXPECT().Run(setPolicyMatcher).
 					Return("Permission denied (you must be root)", errDummy)
 				return runner
 			},
-			unsupportedMessage: "Permission denied (you must be root) (exit code 4)",
+			criticalErrWrapped: ErrNetAdminMissing,
+			criticalErrMessage: "NET_ADMIN capability is missing: " +
+				"Permission denied (you must be root)",
 		},
 		"set policy unsupported": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("\nChain INPUT (policy "+inputPolicy+")\nxx\n", nil)
-				runner.EXPECT().Run(newSetPolicyMatcher(path, inputPolicy)).
+				runner.EXPECT().Run(setPolicyMatcher).
 					Return("some output", errDummy)
 				return runner
 			},
@@ -239,12 +136,11 @@ func Test_testIptablesPath(t *testing.T) {
 		"success": {
 			buildRunner: func(ctrl *gomock.Controller) command.Runner {
 				runner := NewMockRunner(ctrl)
-				runner.EXPECT().Run(newAppendTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newDeleteTestRuleMatcher(path)).Return("", nil)
-				runner.EXPECT().Run(newListInputRulesMatcher(path)).
+				runner.EXPECT().Run(appendTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(deleteTestRuleMatcher).Return("", nil)
+				runner.EXPECT().Run(listInputRulesMatcher).
 					Return("\nChain INPUT (policy "+inputPolicy+")\nxx\n", nil)
-				runner.EXPECT().Run(newSetPolicyMatcher(path, inputPolicy)).
-					Return("some output", nil)
+				runner.EXPECT().Run(setPolicyMatcher).Return("some output", nil)
 				return runner
 			},
 			ok: true,
--- a/internal/firewall/vpn.go
+++ b/internal/firewall/vpn.go
@@ -45,13 +45,13 @@ func (c *Config) SetVPNConnection(ctx context.Context,

 	for _, defaultRoute := range c.defaultRoutes {
 		if err := c.acceptOutputTrafficToVPN(ctx, defaultRoute.NetInterface, connection, remove); err != nil {
-			return fmt.Errorf("allowing output traffic through VPN connection: %w", err)
+			return fmt.Errorf("cannot allow output traffic through VPN connection: %w", err)
 		}
 	}
 	c.vpnConnection = connection

 	if err = c.acceptOutputThroughInterface(ctx, vpnIntf, remove); err != nil {
-		return fmt.Errorf("accepting output traffic through interface %s: %w", vpnIntf, err)
+		return fmt.Errorf("cannot accept output traffic through interface %s: %w", vpnIntf, err)
 	}
 	c.vpnIntf = vpnIntf

--- a/internal/healthcheck/health.go
+++ b/internal/healthcheck/health.go
@@ -74,12 +74,12 @@ func (s *Server) healthCheck(ctx context.Context) (err error) {
 	const dialNetwork = "tcp4"
 	connection, err := s.dialer.DialContext(ctx, dialNetwork, address)
 	if err != nil {
-		return fmt.Errorf("dialing: %w", err)
+		return fmt.Errorf("cannot dial: %w", err)
 	}

 	err = connection.Close()
 	if err != nil {
-		return fmt.Errorf("closing connection: %w", err)
+		return fmt.Errorf("cannot close connection: %w", err)
 	}

 	return nil
@@ -91,7 +91,7 @@ func makeAddressToDial(address string) (addressToDial string, err error) {
 		addrErr := new(net.AddrError)
 		ok := errors.As(err, &addrErr)
 		if !ok || addrErr.Err != "missing port in address" {
-			return "", fmt.Errorf("splitting host and port from address: %w", err)
+			return "", fmt.Errorf("cannot split host and port from address: %w", err)
 		}
 		host = address
 		const defaultPort = "443"
--- a/internal/healthcheck/health_test.go
+++ b/internal/healthcheck/health_test.go
@@ -85,7 +85,7 @@ func Test_makeAddressToDial(t *testing.T) {
 		},
 		"bad address": {
 			address: "test.com::",
-			err:     fmt.Errorf("splitting host and port from address: address test.com::: too many colons in address"), //nolint:lll
+			err:     fmt.Errorf("cannot split host and port from address: address test.com::: too many colons in address"), //nolint:lll
 		},
 	}

--- a/internal/healthcheck/openvpn.go
+++ b/internal/healthcheck/openvpn.go
@@ -15,8 +15,7 @@ type vpnHealth struct {

 func (s *Server) onUnhealthyVPN(ctx context.Context) {
 	s.logger.Info("program has been unhealthy for " +
-		s.vpn.healthyWait.String() + ": restarting VPN " +
-		"(see https://github.com/qdm12/gluetun/wiki/Healthcheck)")
+		s.vpn.healthyWait.String() + ": restarting VPN")
 	_, _ = s.vpn.loop.ApplyStatus(ctx, constants.Stopped)
 	_, _ = s.vpn.loop.ApplyStatus(ctx, constants.Running)
 	s.vpn.healthyWait += *s.config.VPN.Addition
--- a/internal/healthcheck/run.go
+++ b/internal/healthcheck/run.go
@@ -14,10 +14,8 @@ func (s *Server) Run(ctx context.Context, done chan<- struct{}) {
 	go s.runHealthcheckLoop(ctx, loopDone)

 	server := http.Server{
-		Addr:              s.config.ServerAddress,
-		Handler:           s.handler,
-		ReadHeaderTimeout: s.config.ReadHeaderTimeout,
-		ReadTimeout:       s.config.ReadTimeout,
+		Addr:    s.config.ServerAddress,
+		Handler: s.handler,
 	}
 	serverDone := make(chan struct{})
 	go func() {
--- a/internal/httpproxy/auth.go
+++ b/internal/httpproxy/auth.go
@@ -2,7 +2,6 @@ package httpproxy

 import (
 	"encoding/base64"
-	"fmt"
 	"net/http"
 	"strings"
 )
@@ -33,8 +32,7 @@ func (h *handler) isAuthorized(responseWriter http.ResponseWriter, request *http
 		return false
 	}
 	if h.username != usernamePassword[0] || h.password != usernamePassword[1] {
-		h.logger.Info(fmt.Sprintf("Username (%q) or password (%q) mismatch from %s",
-			usernamePassword[0], usernamePassword[1], request.RemoteAddr))
+		h.logger.Info("Username or password mismatch from " + request.RemoteAddr)
 		h.logger.Debug("username provided \"" + usernamePassword[0] +
 			"\" and password provided \"" + usernamePassword[1] + "\"")
 		responseWriter.WriteHeader(http.StatusUnauthorized)
--- a/internal/httpproxy/run.go
+++ b/internal/httpproxy/run.go
@@ -23,7 +23,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 		settings := l.state.GetSettings()
 		server := New(runCtx, settings.ListeningAddress, l.logger,
 			*settings.Stealth, *settings.Log, *settings.User,
-			*settings.Password, settings.ReadHeaderTimeout, settings.ReadTimeout)
+			*settings.Password)

 		errorCh := make(chan error)
 		go server.Run(runCtx, errorCh)
--- a/internal/httpproxy/server.go
+++ b/internal/httpproxy/server.go
@@ -8,38 +8,28 @@ import (
 )

 type Server struct {
-	address           string
-	handler           http.Handler
-	logger            infoErrorer
-	internalWG        *sync.WaitGroup
-	readHeaderTimeout time.Duration
-	readTimeout       time.Duration
+	address    string
+	handler    http.Handler
+	logger     infoErrorer
+	internalWG *sync.WaitGroup
 }

 func New(ctx context.Context, address string, logger Logger,
-	stealth, verbose bool, username, password string,
-	readHeaderTimeout, readTimeout time.Duration) *Server {
+	stealth, verbose bool, username, password string) *Server {
 	wg := &sync.WaitGroup{}
 	return &Server{
-		address:           address,
-		handler:           newHandler(ctx, wg, logger, stealth, verbose, username, password),
-		logger:            logger,
-		internalWG:        wg,
-		readHeaderTimeout: readHeaderTimeout,
-		readTimeout:       readTimeout,
+		address:    address,
+		handler:    newHandler(ctx, wg, logger, stealth, verbose, username, password),
+		logger:     logger,
+		internalWG: wg,
 	}
 }

 func (s *Server) Run(ctx context.Context, errorCh chan<- error) {
-	server := http.Server{
-		Addr:              s.address,
-		Handler:           s.handler,
-		ReadHeaderTimeout: s.readHeaderTimeout,
-		ReadTimeout:       s.readTimeout,
-	}
+	server := http.Server{Addr: s.address, Handler: s.handler}
 	go func() {
 		<-ctx.Done()
-		const shutdownGraceDuration = 100 * time.Millisecond
+		const shutdownGraceDuration = 2 * time.Second
 		shutdownCtx, cancel := context.WithTimeout(context.Background(), shutdownGraceDuration)
 		defer cancel()
 		if err := server.Shutdown(shutdownCtx); err != nil {
--- a/internal/httpserver/helpers_test.go
+++ b/internal/httpserver/helpers_test.go
@@ -2,10 +2,13 @@ package httpserver

 import (
 	"regexp"
+	"time"

 	gomock "github.com/golang/mock/gomock"
 )

+func durationPtr(d time.Duration) *time.Duration { return &d }
+
 var _ Logger = (*testLogger)(nil)

 type testLogger struct{}
--- a/internal/httpserver/run.go
+++ b/internal/httpserver/run.go
@@ -11,12 +11,7 @@ import (
 // The done channel has an error written to when the HTTP server
 // is terminated, and can be nil or not nil.
 func (s *Server) Run(ctx context.Context, ready chan<- struct{}, done chan<- struct{}) {
-	server := http.Server{
-		Addr:              s.address,
-		Handler:           s.handler,
-		ReadHeaderTimeout: s.readHeaderTimeout,
-		ReadTimeout:       s.readTimeout,
-	}
+	server := http.Server{Addr: s.address, Handler: s.handler}

 	crashed := make(chan struct{})
 	shutdownDone := make(chan struct{})
--- a/internal/httpserver/server.go
+++ b/internal/httpserver/server.go
@@ -9,13 +9,11 @@ import (
 // Server is an HTTP server implementation, which uses
 // the HTTP handler provided.
 type Server struct {
-	address           string
-	addressSet        chan struct{}
-	handler           http.Handler
-	logger            Logger
-	readHeaderTimeout time.Duration
-	readTimeout       time.Duration
-	shutdownTimeout   time.Duration
+	address         string
+	addressSet      chan struct{}
+	handler         http.Handler
+	logger          Logger
+	shutdownTimeout time.Duration
 }

 // New creates a new HTTP server with the given settings.
@@ -28,12 +26,10 @@ func New(settings Settings) (s *Server, err error) {
 	}

 	return &Server{
-		address:           settings.Address,
-		addressSet:        make(chan struct{}),
-		handler:           settings.Handler,
-		logger:            settings.Logger,
-		readHeaderTimeout: settings.ReadHeaderTimeout,
-		readTimeout:       settings.ReadTimeout,
-		shutdownTimeout:   settings.ShutdownTimeout,
+		address:         settings.Address,
+		addressSet:      make(chan struct{}),
+		handler:         settings.Handler,
+		logger:          settings.Logger,
+		shutdownTimeout: *settings.ShutdownTimeout,
 	}, nil
 }
--- a/internal/httpserver/server_test.go
+++ b/internal/httpserver/server_test.go
@@ -29,20 +29,16 @@ func Test_New(t *testing.T) {
 		},
 		"filled settings": {
 			settings: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: &Server{
-				address:           ":8001",
-				handler:           someHandler,
-				logger:            someLogger,
-				readHeaderTimeout: time.Second,
-				readTimeout:       time.Second,
-				shutdownTimeout:   time.Second,
+				address:         ":8001",
+				handler:         someHandler,
+				logger:          someLogger,
+				shutdownTimeout: time.Second,
 			},
 		},
 	}
--- a/internal/httpserver/settings.go
+++ b/internal/httpserver/settings.go
@@ -22,34 +22,23 @@ type Settings struct {
 	// Logger is the logger to use.
 	// It must be set and cannot be left to nil.
 	Logger Logger
-	// ReadHeaderTimeout is the HTTP header read timeout duration
-	// of the HTTP server. It defaults to 3 seconds if left unset.
-	ReadHeaderTimeout time.Duration
-	// ReadTimeout is the HTTP read timeout duration
-	// of the HTTP server. It defaults to 3 seconds if left unset.
-	ReadTimeout time.Duration
 	// ShutdownTimeout is the shutdown timeout duration
-	// of the HTTP server. It defaults to 3 seconds if left unset.
-	ShutdownTimeout time.Duration
+	// of the HTTP server. It defaults to 3 seconds.
+	ShutdownTimeout *time.Duration
 }

 func (s *Settings) SetDefaults() {
 	s.Address = helpers.DefaultString(s.Address, ":8000")
-	const defaultReadTimeout = 3 * time.Second
-	s.ReadHeaderTimeout = helpers.DefaultDuration(s.ReadHeaderTimeout, defaultReadTimeout)
-	s.ReadTimeout = helpers.DefaultDuration(s.ReadTimeout, defaultReadTimeout)
 	const defaultShutdownTimeout = 3 * time.Second
 	s.ShutdownTimeout = helpers.DefaultDuration(s.ShutdownTimeout, defaultShutdownTimeout)
 }

 func (s Settings) Copy() Settings {
 	return Settings{
-		Address:           s.Address,
-		Handler:           s.Handler,
-		Logger:            s.Logger,
-		ReadHeaderTimeout: s.ReadHeaderTimeout,
-		ReadTimeout:       s.ReadTimeout,
-		ShutdownTimeout:   s.ShutdownTimeout,
+		Address:         s.Address,
+		Handler:         s.Handler,
+		Logger:          s.Logger,
+		ShutdownTimeout: helpers.CopyDurationPtr(s.ShutdownTimeout),
 	}
 }

@@ -59,8 +48,6 @@ func (s *Settings) MergeWith(other Settings) {
 	if s.Logger == nil {
 		s.Logger = other.Logger
 	}
-	s.ReadHeaderTimeout = helpers.MergeWithDuration(s.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	s.ReadTimeout = helpers.MergeWithDuration(s.ReadTimeout, other.ReadTimeout)
 	s.ShutdownTimeout = helpers.MergeWithDuration(s.ShutdownTimeout, other.ShutdownTimeout)
 }

@@ -70,17 +57,13 @@ func (s *Settings) OverrideWith(other Settings) {
 	if other.Logger != nil {
 		s.Logger = other.Logger
 	}
-	s.ReadHeaderTimeout = helpers.OverrideWithDuration(s.ReadHeaderTimeout, other.ReadHeaderTimeout)
-	s.ReadTimeout = helpers.OverrideWithDuration(s.ReadTimeout, other.ReadTimeout)
 	s.ShutdownTimeout = helpers.OverrideWithDuration(s.ShutdownTimeout, other.ShutdownTimeout)
 }

 var (
-	ErrHandlerIsNotSet           = errors.New("HTTP handler cannot be left unset")
-	ErrLoggerIsNotSet            = errors.New("logger cannot be left unset")
-	ErrReadHeaderTimeoutTooSmall = errors.New("read header timeout is too small")
-	ErrReadTimeoutTooSmall       = errors.New("read timeout is too small")
-	ErrShutdownTimeoutTooSmall   = errors.New("shutdown timeout is too small")
+	ErrHandlerIsNotSet         = errors.New("HTTP handler cannot be left unset")
+	ErrLoggerIsNotSet          = errors.New("logger cannot be left unset")
+	ErrShutdownTimeoutTooSmall = errors.New("shutdown timeout is too small")
 )

 func (s Settings) Validate() (err error) {
@@ -98,24 +81,11 @@ func (s Settings) Validate() (err error) {
 		return ErrLoggerIsNotSet
 	}

-	const minReadTimeout = time.Millisecond
-	if s.ReadHeaderTimeout < minReadTimeout {
-		return fmt.Errorf("%w: %s must be at least %s",
-			ErrReadHeaderTimeoutTooSmall,
-			s.ReadHeaderTimeout, minReadTimeout)
-	}
-
-	if s.ReadTimeout < minReadTimeout {
-		return fmt.Errorf("%w: %s must be at least %s",
-			ErrReadTimeoutTooSmall,
-			s.ReadTimeout, minReadTimeout)
-	}
-
 	const minShutdownTimeout = 5 * time.Millisecond
-	if s.ShutdownTimeout < minShutdownTimeout {
+	if *s.ShutdownTimeout < minShutdownTimeout {
 		return fmt.Errorf("%w: %s must be at least %s",
 			ErrShutdownTimeoutTooSmall,
-			s.ShutdownTimeout, minShutdownTimeout)
+			*s.ShutdownTimeout, minShutdownTimeout)
 	}

 	return nil
@@ -124,9 +94,7 @@ func (s Settings) Validate() (err error) {
 func (s Settings) ToLinesNode() (node *gotree.Node) {
 	node = gotree.New("HTTP server settings:")
 	node.Appendf("Listening address: %s", s.Address)
-	node.Appendf("Read header timeout: %s", s.ReadHeaderTimeout)
-	node.Appendf("Read timeout: %s", s.ReadTimeout)
-	node.Appendf("Shutdown timeout: %s", s.ShutdownTimeout)
+	node.Appendf("Shutdown timeout: %s", *s.ShutdownTimeout)
 	return node
 }

--- a/internal/httpserver/settings_test.go
+++ b/internal/httpserver/settings_test.go
@@ -21,24 +21,18 @@ func Test_Settings_SetDefaults(t *testing.T) {
 		"empty settings": {
 			settings: Settings{},
 			expected: Settings{
-				Address:           ":8000",
-				ReadHeaderTimeout: defaultTimeout,
-				ReadTimeout:       defaultTimeout,
-				ShutdownTimeout:   defaultTimeout,
+				Address:         ":8000",
+				ShutdownTimeout: durationPtr(defaultTimeout),
 			},
 		},
 		"filled settings": {
 			settings: Settings{
-				Address:           ":8001",
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 	}
@@ -68,20 +62,16 @@ func Test_Settings_Copy(t *testing.T) {
 		"empty settings": {},
 		"filled settings": {
 			settings: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 	}
@@ -112,38 +102,30 @@ func Test_Settings_MergeWith(t *testing.T) {
 		"merge empty with empty": {},
 		"merge empty with filled": {
 			other: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 		"merge filled with empty": {
 			settings: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 	}
@@ -174,62 +156,48 @@ func Test_Settings_OverrideWith(t *testing.T) {
 		"override empty with empty": {},
 		"override empty with filled": {
 			other: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 		"override filled with empty": {
 			settings: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			expected: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 		"override filled with filled": {
 			settings: Settings{
-				Address:           ":8001",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Second,
-				ReadTimeout:       time.Second,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8001",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			other: Settings{
-				Address:           ":8002",
-				ReadHeaderTimeout: time.Hour,
-				ReadTimeout:       time.Hour,
-				ShutdownTimeout:   time.Hour,
+				Address:         ":8002",
+				ShutdownTimeout: durationPtr(time.Hour),
 			},
 			expected: Settings{
-				Address:           ":8002",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Hour,
-				ReadTimeout:       time.Hour,
-				ShutdownTimeout:   time.Hour,
+				Address:         ":8002",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Hour),
 			},
 		},
 	}
@@ -279,47 +247,22 @@ func Test_Settings_Validate(t *testing.T) {
 			errWrapped: ErrLoggerIsNotSet,
 			errMessage: ErrLoggerIsNotSet.Error(),
 		},
-		"read header timeout too small": {
-			settings: Settings{
-				Address:           ":8000",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Nanosecond,
-			},
-			errWrapped: ErrReadHeaderTimeoutTooSmall,
-			errMessage: "read header timeout is too small: 1ns must be at least 1ms",
-		},
-		"read timeout too small": {
-			settings: Settings{
-				Address:           ":8000",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Millisecond,
-				ReadTimeout:       time.Nanosecond,
-			},
-			errWrapped: ErrReadTimeoutTooSmall,
-			errMessage: "read timeout is too small: 1ns must be at least 1ms",
-		},
 		"shutdown timeout too small": {
 			settings: Settings{
-				Address:           ":8000",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Millisecond,
-				ReadTimeout:       time.Millisecond,
-				ShutdownTimeout:   time.Millisecond,
+				Address:         ":8000",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Millisecond),
 			},
 			errWrapped: ErrShutdownTimeoutTooSmall,
 			errMessage: "shutdown timeout is too small: 1ms must be at least 5ms",
 		},
 		"valid settings": {
 			settings: Settings{
-				Address:           ":8000",
-				Handler:           someHandler,
-				Logger:            someLogger,
-				ReadHeaderTimeout: time.Millisecond,
-				ReadTimeout:       time.Millisecond,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8000",
+				Handler:         someHandler,
+				Logger:          someLogger,
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 		},
 	}
@@ -348,15 +291,11 @@ func Test_Settings_String(t *testing.T) {
 	}{
 		"all values": {
 			settings: Settings{
-				Address:           ":8000",
-				ReadHeaderTimeout: time.Millisecond,
-				ReadTimeout:       time.Millisecond,
-				ShutdownTimeout:   time.Second,
+				Address:         ":8000",
+				ShutdownTimeout: durationPtr(time.Second),
 			},
 			s: `HTTP server settings:
 ├── Listening address: :8000
-├── Read header timeout: 1ms
-├── Read timeout: 1ms
 └── Shutdown timeout: 1s`,
 		},
 	}
--- a/internal/models/markdown.go
+++ b/internal/models/markdown.go
@@ -5,7 +5,6 @@ import (
 	"strings"

 	"github.com/qdm12/gluetun/internal/constants/providers"
-	"github.com/qdm12/gluetun/internal/constants/vpn"
 )

 func boolToMarkdown(b bool) string {
@@ -27,11 +26,9 @@ const (
 	hostnameHeader    = "Hostname"
 	ispHeader         = "ISP"
 	multiHopHeader    = "MultiHop"
-	nameHeader        = "Name"
 	numberHeader      = "Number"
 	ownedHeader       = "Owned"
 	portForwardHeader = "Port forwarding"
-	premiumHeader     = "Premium"
 	regionHeader      = "Region"
 	streamHeader      = "Stream"
 	tcpHeader         = "TCP"
@@ -59,16 +56,12 @@ func (s *Server) ToMarkdown(headers ...string) (markdown string) {
 			fields[i] = s.ISP
 		case multiHopHeader:
 			fields[i] = boolToMarkdown(s.MultiHop)
-		case nameHeader:
-			fields[i] = s.ServerName
 		case numberHeader:
 			fields[i] = fmt.Sprint(s.Number)
 		case ownedHeader:
 			fields[i] = boolToMarkdown(s.Owned)
 		case portForwardHeader:
 			fields[i] = boolToMarkdown(s.PortForward)
-		case premiumHeader:
-			fields[i] = boolToMarkdown(s.Premium)
 		case regionHeader:
 			fields[i] = s.Region
 		case streamHeader:
@@ -76,7 +69,7 @@ func (s *Server) ToMarkdown(headers ...string) (markdown string) {
 		case tcpHeader:
 			fields[i] = boolToMarkdown(s.TCP)
 		case udpHeader:
-			fields[i] = boolToMarkdown(s.UDP || s.VPN == vpn.Wireguard)
+			fields[i] = boolToMarkdown(s.UDP)
 		case vpnHeader:
 			fields[i] = s.VPN
 		}
@@ -102,9 +95,6 @@ func (s *Servers) ToMarkdown(vpnProvider string) (markdown string) {

 func getMarkdownHeaders(vpnProvider string) (headers []string) {
 	switch vpnProvider {
-	case providers.Airvpn:
-		return []string{regionHeader, countryHeader, cityHeader, vpnHeader,
-			udpHeader, tcpHeader, hostnameHeader, nameHeader}
 	case providers.Cyberghost:
 		return []string{countryHeader, hostnameHeader, tcpHeader, udpHeader}
 	case providers.Expressvpn:
@@ -133,14 +123,10 @@ func getMarkdownHeaders(vpnProvider string) (headers []string) {
 		return []string{countryHeader, regionHeader, cityHeader, hostnameHeader, freeHeader}
 	case providers.Purevpn:
 		return []string{countryHeader, regionHeader, cityHeader, hostnameHeader, tcpHeader, udpHeader}
-	case providers.SlickVPN:
-		return []string{regionHeader, countryHeader, cityHeader, hostnameHeader}
 	case providers.Surfshark:
 		return []string{regionHeader, countryHeader, cityHeader, hostnameHeader, multiHopHeader, tcpHeader, udpHeader}
 	case providers.Torguard:
 		return []string{countryHeader, cityHeader, hostnameHeader, tcpHeader, udpHeader}
-	case providers.VPNSecure:
-		return []string{regionHeader, cityHeader, hostnameHeader, premiumHeader}
 	case providers.VPNUnlimited:
 		return []string{countryHeader, cityHeader, hostnameHeader, freeHeader, streamHeader, tcpHeader, udpHeader}
 	case providers.Vyprvpn:
--- a/internal/models/server.go
+++ b/internal/models/server.go
@@ -29,7 +29,6 @@ type Server struct {
 	WgPubKey    string   `json:"wgpubkey,omitempty"`
 	Free        bool     `json:"free,omitempty"`
 	Stream      bool     `json:"stream,omitempty"`
-	Premium     bool     `json:"premium,omitempty"`
 	PortForward bool     `json:"port_forward,omitempty"`
 	Keep        bool     `json:"keep,omitempty"`
 	IPs         []net.IP `json:"ips,omitempty"`
@@ -39,8 +38,7 @@ var (
 	ErrVPNFieldEmpty           = errors.New("vpn field is empty")
 	ErrHostnameFieldEmpty      = errors.New("hostname field is empty")
 	ErrIPsFieldEmpty           = errors.New("ips field is empty")
-	ErrNoNetworkProtocol       = errors.New("both TCP and UDP fields are false for OpenVPN")
-	ErrNetworkProtocolSet      = errors.New("no network protocol should be set")
+	ErrNoNetworkProtocol       = errors.New("both TCP and UDP fields are false")
 	ErrWireguardPublicKeyEmpty = errors.New("wireguard public key field is empty")
 )

@@ -52,9 +50,7 @@ func (s *Server) HasMinimumInformation() (err error) {
 		return ErrHostnameFieldEmpty
 	case len(s.IPs) == 0:
 		return ErrIPsFieldEmpty
-	case s.VPN == vpn.Wireguard && (s.TCP || s.UDP):
-		return ErrNetworkProtocolSet
-	case s.VPN == vpn.OpenVPN && !s.TCP && !s.UDP:
+	case !s.TCP && !s.UDP:
 		return ErrNoNetworkProtocol
 	case s.VPN == vpn.Wireguard && s.WgPubKey == "":
 		return ErrWireguardPublicKeyEmpty
--- a/internal/models/servers.go
+++ b/internal/models/servers.go
@@ -27,13 +27,13 @@ func (a *AllServers) MarshalJSON() (data []byte, err error) {

 	_, err = buffer.WriteString("{")
 	if err != nil {
-		return nil, fmt.Errorf("writing opening bracket: %w", err)
+		return nil, fmt.Errorf("cannot write opening bracket: %w", err)
 	}

 	versionString := fmt.Sprintf(`"version":%d`, a.Version)
 	_, err = buffer.WriteString(versionString)
 	if err != nil {
-		return nil, fmt.Errorf("writing schema version string: %w", err)
+		return nil, fmt.Errorf("cannot write schema version string: %w", err)
 	}

 	sortedProviders := make(sort.StringSlice, 0, len(a.ProviderToServers))
@@ -46,26 +46,26 @@ func (a *AllServers) MarshalJSON() (data []byte, err error) {
 		providerKey := fmt.Sprintf(`,"%s":`, provider)
 		_, err = buffer.WriteString(providerKey)
 		if err != nil {
-			return nil, fmt.Errorf("writing provider key %s: %w",
+			return nil, fmt.Errorf("cannot write provider key %s: %w",
 				providerKey, err)
 		}

 		servers := a.ProviderToServers[provider]
 		serversJSON, err := json.Marshal(servers)
 		if err != nil {
-			return nil, fmt.Errorf("encoding servers for provider %s: %w",
+			return nil, fmt.Errorf("failed encoding servers for provider %s: %w",
 				provider, err)
 		}
 		_, err = buffer.Write(serversJSON)
 		if err != nil {
-			return nil, fmt.Errorf("writing JSON servers data for provider %s: %w",
+			return nil, fmt.Errorf("cannot write JSON servers data for provider %s: %w",
 				provider, err)
 		}
 	}

 	_, err = buffer.WriteString("}")
 	if err != nil {
-		return nil, fmt.Errorf("writing closing bracket: %w", err)
+		return nil, fmt.Errorf("cannot write closing bracket: %w", err)
 	}

 	return buffer.Bytes(), nil
@@ -127,14 +127,14 @@ func (a *AllServers) UnmarshalJSON(data []byte) (err error) {

 		jsonValue, err := json.Marshal(value)
 		if err != nil {
-			return fmt.Errorf("encoding %s servers: %w",
+			return fmt.Errorf("cannot marshal %s servers: %w",
 				key, err)
 		}

 		var servers Servers
 		err = json.Unmarshal(jsonValue, &servers)
 		if err != nil {
-			return fmt.Errorf("decoding %s servers: %w",
+			return fmt.Errorf("cannot unmarshal %s servers: %w",
 				key, err)
 		}

--- a/Show More
+++ b/Show More