Chore(deps): Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -37,7 +37,7 @@ jobs:
     env:
       DOCKER_BUILDKIT: "1"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: reviewdog/action-misspell@v1
         with:
@@ -78,7 +78,7 @@ jobs:
     runs-on: ubuntu-latest
     environment: secrets
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - run: docker build -t qmcgaw/gluetun .
 
@@ -93,6 +93,9 @@ jobs:
       - name: Run Gluetun container with Mullvad configuration
         run: echo -e "${{ secrets.MULLVAD_WIREGUARD_PRIVATE_KEY }}\n${{ secrets.MULLVAD_WIREGUARD_ADDRESS }}" | ./ci/runner mullvad
 
+      - name: Run Gluetun container with ProtonVPN configuration
+        run: echo -e "${{ secrets.PROTONVPN_WIREGUARD_PRIVATE_KEY }}" | ./ci/runner protonvpn
+
   codeql:
     runs-on: ubuntu-latest
     permissions:
@@ -100,7 +103,7 @@ jobs:
       contents: read
       security-events: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-go@v6
         with:
           go-version-file: go.mod
@@ -118,14 +121,14 @@ jobs:
         github.event_name == 'release' ||
         (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository && github.actor != 'dependabot[bot]')
       )
-    needs: [verify, codeql]
+    needs: [verify, verify-private, codeql]
     permissions:
       actions: read
       contents: read
       packages: write
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       # extract metadata (tags, labels) for Docker
       # https://github.com/docker/metadata-action

.github/workflows/labels.yml

@@ -11,7 +11,7 @@ jobs:
       issues: write
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: crazy-max/ghaction-github-labeler@v5
         with:
           yaml-file: .github/labels.yml

.github/workflows/markdown.yml

@@ -18,7 +18,7 @@ jobs:
       actions: read
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: DavidAnson/markdownlint-cli2-action@v21
         with:

Dockerfile

@@ -163,8 +163,9 @@ ENV VPN_SERVICE_PROVIDER=pia \
     LOG_LEVEL=info \
     # Health
     HEALTH_SERVER_ADDRESS=127.0.0.1:9999 \
-    HEALTH_TARGET_ADDRESS=cloudflare.com:443 \
+    HEALTH_TARGET_ADDRESSES=cloudflare.com:443,github.com:443 \
-    HEALTH_ICMP_TARGET_IP=1.1.1.1 \
+    HEALTH_ICMP_TARGET_IPS=1.1.1.1,8.8.8.8 \
+    HEALTH_SMALL_CHECK_TYPE=icmp \
     HEALTH_RESTART_VPN=on \
     # DNS
     DNS_SERVER=on \
@@ -207,7 +208,7 @@ ENV VPN_SERVICE_PROVIDER=pia \
     UPDATER_PERIOD=0 \
     UPDATER_MIN_RATIO=0.8 \
     UPDATER_VPN_SERVICE_PROVIDERS= \
-    UPDATER_PROTONVPN_USERNAME= \
+    UPDATER_PROTONVPN_EMAIL= \
     UPDATER_PROTONVPN_PASSWORD= \
     # Public IP
     PUBLICIP_FILE="/tmp/gluetun/ip" \

ci/cmd/main.go

@@ -21,6 +21,8 @@ func main() {
 	switch os.Args[1] {
 	case "mullvad":
 		err = internal.MullvadTest(ctx)
+	case "protonvpn":
+		err = internal.ProtonVPNTest(ctx)
 	default:
 		err = fmt.Errorf("unknown command: %s", os.Args[1])
 	}

ci/internal/mullvad.go

@@ -1,193 +1,27 @@
 package internal
 
 import (
-	"bufio"
 	"context"
 	"fmt"
-	"io"
-	"os"
-	"regexp"
-	"strings"
-	"time"
-
-	"github.com/docker/docker/api/types/container"
-	"github.com/docker/docker/api/types/network"
-	"github.com/docker/docker/client"
-	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 func MullvadTest(ctx context.Context) error {
-	secrets, err := readSecrets(ctx)
+	expectedSecrets := []string{
+		"Wireguard private key",
+		"Wireguard address",
+	}
+	secrets, err := readSecrets(ctx, expectedSecrets)
 	if err != nil {
 		return fmt.Errorf("reading secrets: %w", err)
 	}
 
-	const timeout = 15 * time.Second
+	env := []string{
-	ctx, cancel := context.WithTimeout(ctx, timeout)
+		"VPN_SERVICE_PROVIDER=mullvad",
-	defer cancel()
+		"VPN_TYPE=wireguard",
-
+		"LOG_LEVEL=debug",
-	client, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+		"SERVER_COUNTRIES=USA",
-	if err != nil {
+		"WIREGUARD_PRIVATE_KEY=" + secrets[0],
-		return fmt.Errorf("creating Docker client: %w", err)
+		"WIREGUARD_ADDRESSES=" + secrets[1],
-	}
-	defer client.Close()
-
-	config := &container.Config{
-		Image:       "qmcgaw/gluetun",
-		StopTimeout: ptrTo(3),
-		Env: []string{
-			"VPN_SERVICE_PROVIDER=mullvad",
-			"VPN_TYPE=wireguard",
-			"LOG_LEVEL=debug",
-			"SERVER_COUNTRIES=USA",
-			"WIREGUARD_PRIVATE_KEY=" + secrets.mullvadWireguardPrivateKey,
-			"WIREGUARD_ADDRESSES=" + secrets.mullvadWireguardAddress,
-		},
-	}
-	hostConfig := &container.HostConfig{
-		AutoRemove: true,
-		CapAdd:     []string{"NET_ADMIN", "NET_RAW"},
-	}
-	networkConfig := (*network.NetworkingConfig)(nil)
-	platform := (*v1.Platform)(nil)
-	const containerName = "" // auto-generated name
-
-	response, err := client.ContainerCreate(ctx, config, hostConfig, networkConfig, platform, containerName)
-	if err != nil {
-		return fmt.Errorf("creating container: %w", err)
-	}
-	for _, warning := range response.Warnings {
-		fmt.Println("Warning during container creation:", warning)
-	}
-	containerID := response.ID
-	defer stopContainer(client, containerID)
-
-	beforeStartTime := time.Now()
-
-	err = client.ContainerStart(ctx, containerID, container.StartOptions{})
-	if err != nil {
-		return fmt.Errorf("starting container: %w", err)
-	}
-
-	return waitForLogLine(ctx, client, containerID, beforeStartTime)
-}
-
-func ptrTo[T any](v T) *T { return &v }
-
-type secrets struct {
-	mullvadWireguardPrivateKey string
-	mullvadWireguardAddress    string
-}
-
-func readSecrets(ctx context.Context) (secrets, error) {
-	expectedSecrets := [...]string{
-		"Mullvad Wireguard private key",
-		"Mullvad Wireguard address",
-	}
-
-	scanner := bufio.NewScanner(os.Stdin)
-	lines := make([]string, 0, len(expectedSecrets))
-
-	for i := range expectedSecrets {
-		fmt.Println("🤫 reading", expectedSecrets[i], "from Stdin...")
-		if !scanner.Scan() {
-			break
-		}
-		lines = append(lines, strings.TrimSpace(scanner.Text()))
-		if ctx.Err() != nil {
-			return secrets{}, ctx.Err()
-		}
-	}
-
-	if err := scanner.Err(); err != nil {
-		return secrets{}, fmt.Errorf("reading secrets from stdin: %w", err)
-	}
-
-	if len(lines) < len(expectedSecrets) {
-		return secrets{}, fmt.Errorf("expected %d secrets via Stdin, but only received %d",
-			len(expectedSecrets), len(lines))
-	}
-	for i, line := range lines {
-		if line == "" {
-			return secrets{}, fmt.Errorf("secret on line %d/%d was empty", i+1, len(lines))
-		}
-	}
-
-	return secrets{
-		mullvadWireguardPrivateKey: lines[0],
-		mullvadWireguardAddress:    lines[1],
-	}, nil
-}
-
-func stopContainer(client *client.Client, containerID string) {
-	const stopTimeout = 5 * time.Second // must be higher than 3s, see above [container.Config]'s StopTimeout field
-	stopCtx, stopCancel := context.WithTimeout(context.Background(), stopTimeout)
-	defer stopCancel()
-
-	err := client.ContainerStop(stopCtx, containerID, container.StopOptions{})
-	if err != nil {
-		fmt.Println("failed to stop container:", err)
-	}
-}
-
-var successRegexp = regexp.MustCompile(`^.+Public IP address is .+$`)
-
-func waitForLogLine(ctx context.Context, client *client.Client, containerID string,
-	beforeStartTime time.Time,
-) error {
-	logOptions := container.LogsOptions{
-		ShowStdout: true,
-		Follow:     true,
-		Since:      beforeStartTime.Format(time.RFC3339Nano),
-	}
-
-	reader, err := client.ContainerLogs(ctx, containerID, logOptions)
-	if err != nil {
-		return fmt.Errorf("error getting container logs: %w", err)
-	}
-	defer reader.Close()
-
-	var linesSeen []string
-	scanner := bufio.NewScanner(reader)
-	for ctx.Err() == nil {
-		if scanner.Scan() {
-			line := scanner.Text()
-			if len(line) > 8 { // remove Docker log prefix
-				line = line[8:]
-			}
-			linesSeen = append(linesSeen, line)
-			if successRegexp.MatchString(line) {
-				fmt.Println("✅ Success line logged")
-				return nil
-			}
-			continue
-		}
-		err := scanner.Err()
-		if err != nil && err != io.EOF {
-			logSeenLines(linesSeen)
-			return fmt.Errorf("reading log stream: %w", err)
-		}
-
-		// The scanner is either done or cannot read because of EOF
-		fmt.Println("The log scanner stopped")
-		logSeenLines(linesSeen)
-
-		// Check if the container is still running
-		inspect, err := client.ContainerInspect(ctx, containerID)
-		if err != nil {
-			return fmt.Errorf("inspecting container: %w", err)
-		}
-		if !inspect.State.Running {
-			return fmt.Errorf("container stopped unexpectedly while waiting for log line. Exit code: %d", inspect.State.ExitCode)
-		}
-	}
-
-	return ctx.Err()
-}
-
-func logSeenLines(lines []string) {
-	fmt.Println("Logs seen so far:")
-	for _, line := range lines {
-		fmt.Println("  " + line)
 	}
+	return simpleTest(ctx, env)
 }

ci/internal/protonvpn.go

@@ -0,0 +1,25 @@
+package internal
+
+import (
+	"context"
+	"fmt"
+)
+
+func ProtonVPNTest(ctx context.Context) error {
+	expectedSecrets := []string{
+		"Wireguard private key",
+	}
+	secrets, err := readSecrets(ctx, expectedSecrets)
+	if err != nil {
+		return fmt.Errorf("reading secrets: %w", err)
+	}
+
+	env := []string{
+		"VPN_SERVICE_PROVIDER=protonvpn",
+		"VPN_TYPE=wireguard",
+		"LOG_LEVEL=debug",
+		"SERVER_COUNTRIES=United States",
+		"WIREGUARD_PRIVATE_KEY=" + secrets[0],
+	}
+	return simpleTest(ctx, env)
+}

ci/internal/secrets.go

@@ -0,0 +1,42 @@
+package internal
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func readSecrets(ctx context.Context, expectedSecrets []string) (lines []string, err error) {
+	scanner := bufio.NewScanner(os.Stdin)
+	lines = make([]string, 0, len(expectedSecrets))
+
+	for i := range expectedSecrets {
+		fmt.Println("🤫 reading", expectedSecrets[i], "from Stdin...")
+		if !scanner.Scan() {
+			break
+		}
+		lines = append(lines, strings.TrimSpace(scanner.Text()))
+		fmt.Println("🤫 "+expectedSecrets[i], "secret read successfully")
+		if ctx.Err() != nil {
+			return nil, ctx.Err()
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("reading secrets from stdin: %w", err)
+	}
+
+	if len(lines) < len(expectedSecrets) {
+		return nil, fmt.Errorf("expected %d secrets via Stdin, but only received %d",
+			len(expectedSecrets), len(lines))
+	}
+	for i, line := range lines {
+		if line == "" {
+			return nil, fmt.Errorf("secret on line %d/%d was empty", i+1, len(lines))
+		}
+	}
+
+	return lines, nil
+}

ci/internal/simple.go

@@ -0,0 +1,134 @@
+package internal
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"regexp"
+	"time"
+
+	"github.com/docker/docker/api/types/container"
+	"github.com/docker/docker/api/types/network"
+	"github.com/docker/docker/client"
+	v1 "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func ptrTo[T any](v T) *T { return &v }
+
+func simpleTest(ctx context.Context, env []string) error {
+	const timeout = 30 * time.Second
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	client, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	if err != nil {
+		return fmt.Errorf("creating Docker client: %w", err)
+	}
+	defer client.Close()
+
+	config := &container.Config{
+		Image:       "qmcgaw/gluetun",
+		StopTimeout: ptrTo(3),
+		Env:         env,
+	}
+	hostConfig := &container.HostConfig{
+		AutoRemove: true,
+		CapAdd:     []string{"NET_ADMIN", "NET_RAW"},
+	}
+	networkConfig := (*network.NetworkingConfig)(nil)
+	platform := (*v1.Platform)(nil)
+	const containerName = "" // auto-generated name
+
+	response, err := client.ContainerCreate(ctx, config, hostConfig, networkConfig, platform, containerName)
+	if err != nil {
+		return fmt.Errorf("creating container: %w", err)
+	}
+	for _, warning := range response.Warnings {
+		fmt.Println("Warning during container creation:", warning)
+	}
+	containerID := response.ID
+	defer stopContainer(client, containerID)
+
+	beforeStartTime := time.Now()
+
+	err = client.ContainerStart(ctx, containerID, container.StartOptions{})
+	if err != nil {
+		return fmt.Errorf("starting container: %w", err)
+	}
+
+	return waitForLogLine(ctx, client, containerID, beforeStartTime)
+}
+
+func stopContainer(client *client.Client, containerID string) {
+	const stopTimeout = 5 * time.Second // must be higher than 3s, see above [container.Config]'s StopTimeout field
+	stopCtx, stopCancel := context.WithTimeout(context.Background(), stopTimeout)
+	defer stopCancel()
+
+	err := client.ContainerStop(stopCtx, containerID, container.StopOptions{})
+	if err != nil {
+		fmt.Println("failed to stop container:", err)
+	}
+}
+
+var successRegexp = regexp.MustCompile(`^.+Public IP address is .+$`)
+
+func waitForLogLine(ctx context.Context, client *client.Client, containerID string,
+	beforeStartTime time.Time,
+) error {
+	logOptions := container.LogsOptions{
+		ShowStdout: true,
+		Follow:     true,
+		Since:      beforeStartTime.Format(time.RFC3339Nano),
+	}
+
+	reader, err := client.ContainerLogs(ctx, containerID, logOptions)
+	if err != nil {
+		return fmt.Errorf("error getting container logs: %w", err)
+	}
+	defer reader.Close()
+
+	var linesSeen []string
+	scanner := bufio.NewScanner(reader)
+	for ctx.Err() == nil {
+		if scanner.Scan() {
+			line := scanner.Text()
+			if len(line) > 8 { // remove Docker log prefix
+				line = line[8:]
+			}
+			linesSeen = append(linesSeen, line)
+			if successRegexp.MatchString(line) {
+				fmt.Println("✅ Success line logged")
+				return nil
+			}
+			continue
+		}
+		err := scanner.Err()
+		if err != nil && err != io.EOF {
+			logSeenLines(linesSeen)
+			return fmt.Errorf("reading log stream: %w", err)
+		}
+
+		// The scanner is either done or cannot read because of EOF
+		fmt.Println("The log scanner stopped")
+		logSeenLines(linesSeen)
+
+		// Check if the container is still running
+		inspect, err := client.ContainerInspect(ctx, containerID)
+		if err != nil {
+			return fmt.Errorf("inspecting container: %w", err)
+		}
+		if !inspect.State.Running {
+			return fmt.Errorf("container stopped unexpectedly while waiting for log line. Exit code: %d", inspect.State.ExitCode)
+		}
+	}
+
+	return ctx.Err()
+}
+
+func logSeenLines(lines []string) {
+	fmt.Println("Logs seen so far:")
+	for _, line := range lines {
+		fmt.Println("  " + line)
+	}
+}

cmd/gluetun/main.go

@@ -164,6 +164,8 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		}
 	}
 
+	defer fmt.Println(gluetunLogo)
+
 	announcementExp, err := time.Parse(time.RFC3339, "2024-12-01T00:00:00Z")
 	if err != nil {
 		return err
@@ -600,3 +602,34 @@ type RunStarter interface {
 	Start(cmd *exec.Cmd) (stdoutLines, stderrLines <-chan string,
 		waitError <-chan error, err error)
 }
+
+const gluetunLogo = `                         @@@
+                         @@@@
+                        @@@@@@
+                       @@@@.@@                       @@@@@@@@@@
+                       @@@@.@@@                   @@@@@@@@==@@@@
+                      @@@.@..@@                @@@@@@@=@..==@@@@
+            @@@@      @@@.@@.@@              @@@@@@===@@@@.=@@@
+           @...-@@   @@@@.@@.@@@  @@@     @@@@@@=======@@@=@@@@
+           @@@@@@@@  @@@.-%@.+@@@@@@@@  @@@@@%============@@@@
+                     @@@.--@..@@@@.-@@@@@@@==============@@@@
+              @@@@  @@@-@--@@.@@.---@@@@@==============#@@@@@
+              @@@   @@@.@@-@@.@@--@@@@@===============@@@@@@
+                   @@@@.@--@@@@@@@@@@================@@@@@@@
+                   @@@..--@@*@@@@@@================@@@@+*@@
+                   @@@.---@@.@@@@=================@@@@--@@
+                  @@@-.---@@@@@@================@@@@*--@@@
+                  @@@.:-#@@@@@@===============*@@@@.---@@
+                  @@@.-------.@@@============@@@@@@.--@@@
+                 @@@..--------:@@@=========@@@@@@@@.--@@@
+                 @@@.-@@@@@@@@@@@========@@@@@  @@@.--@@
+                 @@.@@@@===============@@@@@ @@@@@@---@@@@@@
+                @@@@@@@==============@@@@@@@@@@@@*@---@@@@@@@@
+                @@@@@@=============@@@@@ @@@...------------.*@@@
+                @@@@%===========@@@@@@ @@@..------@@@@.-----.-@@@
+                @@@@@@.=======@@@@@@  @@@.-------@@@@@@-.------=@@
+               @@@@@@@@@===@@@@@@     @@.------@@@@   @@@@.-----@@@
+               @@@==@@@=@@@@@@@      @@@.-@@@@@@@       @@@@@@@--@@
+               @@@@@@@@@@@@@         @@@@@@@@                @@@@@@@
+                @@@@@@@@             @@@@                       @@@@
+                                                                       `

internal/cli/update.go

@@ -38,7 +38,7 @@ type UpdaterLogger interface {
 func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) error {
 	options := settings.Updater{}
 	var endUserMode, maintainerMode, updateAll bool
-	var csvProviders, ipToken, protonUsername, protonPassword string
+	var csvProviders, ipToken, protonUsername, protonEmail, protonPassword string
 	flagSet := flag.NewFlagSet("update", flag.ExitOnError)
 	flagSet.BoolVar(&endUserMode, "enduser", false, "Write results to /gluetun/servers.json (for end users)")
 	flagSet.BoolVar(&maintainerMode, "maintainer", false,
@@ -50,7 +50,9 @@ func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) e
 	flagSet.BoolVar(&updateAll, "all", false, "Update servers for all VPN providers")
 	flagSet.StringVar(&csvProviders, "providers", "", "CSV string of VPN providers to update server data for")
 	flagSet.StringVar(&ipToken, "ip-token", "", "IP data service token (e.g. ipinfo.io) to use")
-	flagSet.StringVar(&protonUsername, "proton-username", "", "Username to use to authenticate with Proton")
+	flagSet.StringVar(&protonUsername, "proton-username", "",
+		"(Retro-compatibility) Username to use to authenticate with Proton. Use -proton-email instead.") // v4 remove this
+	flagSet.StringVar(&protonEmail, "proton-email", "", "Email to use to authenticate with Proton")
 	flagSet.StringVar(&protonPassword, "proton-password", "", "Password to use to authenticate with Proton")
 	if err := flagSet.Parse(args); err != nil {
 		return err
@@ -70,7 +72,12 @@ func (c *CLI) Update(ctx context.Context, args []string, logger UpdaterLogger) e
 	}
 
 	if slices.Contains(options.Providers, providers.Protonvpn) {
-		options.ProtonUsername = &protonUsername
+		if protonEmail == "" && protonUsername != "" {
+			protonEmail = protonUsername + "@protonmail.com"
+			logger.Warn("use -proton-email instead of -proton-username in the future. " +
+				"This assumes the email is " + protonEmail + " and may not work.")
+		}
+		options.ProtonEmail = &protonEmail
 		options.ProtonPassword = &protonPassword
 	}
 

internal/configuration/settings/errors.go

@@ -37,7 +37,7 @@ var (
 	ErrSystemTimezoneNotValid          = errors.New("timezone is not valid")
 	ErrUpdaterPeriodTooSmall           = errors.New("VPN server data updater period is too small")
 	ErrUpdaterProtonPasswordMissing    = errors.New("proton password is missing")
-	ErrUpdaterProtonUsernameMissing    = errors.New("proton username is missing")
+	ErrUpdaterProtonEmailMissing       = errors.New("proton email is missing")
 	ErrVPNProviderNameNotValid         = errors.New("VPN provider name is not valid")
 	ErrVPNTypeNotValid                 = errors.New("VPN type is not valid")
 	ErrWireguardAllowedIPNotSet        = errors.New("allowed IP is not set")

internal/configuration/settings/health.go

@@ -1,6 +1,7 @@
 package settings
 
 import (
+	"errors"
 	"fmt"
 	"net/netip"
 	"os"
@@ -17,34 +18,63 @@ type Health struct {
 	// for the health check server.
 	// It cannot be the empty string in the internal state.
 	ServerAddress string
-	// TargetAddress is the address (host or host:port)
+	// TargetAddresses are the addresses (host or host:port)
 	// to TCP TLS dial to periodically for the health check.
-	// It cannot be the empty string in the internal state.
+	// Addresses after the first one are used as fallbacks for retries.
-	TargetAddress string
+	// It cannot be empty in the internal state.
-	// ICMPTargetIP is the IP address to use for ICMP echo requests
+	TargetAddresses []string
-	// in the health checker. It can be set to an unspecified address (0.0.0.0)
+	// ICMPTargetIPs are the IP addresses to use for ICMP echo requests
-	// such that the VPN server IP is used, which is also the default behavior.
+	// in the health checker. The slice can be set to a single
-	ICMPTargetIP netip.Addr
+	// unspecified address (0.0.0.0) such that the VPN server IP is used,
+	// although this can be less reliable. It defaults to [1.1.1.1,8.8.8.8],
+	// and cannot be left empty in the internal state.
+	ICMPTargetIPs []netip.Addr
+	// SmallCheckType is the type of small health check to perform.
+	// It can be "icmp" or "dns", and defaults to "icmp".
+	// Note it changes automatically to dns if icmp is not supported.
+	SmallCheckType string
 	// RestartVPN indicates whether to restart the VPN connection
 	// when the healthcheck fails.
 	RestartVPN *bool
 }
 
+var (
+	ErrICMPTargetIPNotValid       = errors.New("ICMP target IP address is not valid")
+	ErrICMPTargetIPsNotCompatible = errors.New("ICMP target IP addresses are not compatible")
+	ErrSmallCheckTypeNotValid     = errors.New("small check type is not valid")
+)
+
 func (h Health) Validate() (err error) {
 	err = validate.ListeningAddress(h.ServerAddress, os.Getuid())
 	if err != nil {
 		return fmt.Errorf("server listening address is not valid: %w", err)
 	}
 
+	for _, ip := range h.ICMPTargetIPs {
+		switch {
+		case !ip.IsValid():
+			return fmt.Errorf("%w: %s", ErrICMPTargetIPNotValid, ip)
+		case ip.IsUnspecified() && len(h.ICMPTargetIPs) > 1:
+			return fmt.Errorf("%w: only a single IP address must be set if it is to be unspecified",
+				ErrICMPTargetIPsNotCompatible)
+		}
+	}
+
+	err = validate.IsOneOf(h.SmallCheckType, "icmp", "dns")
+	if err != nil {
+		return fmt.Errorf("%w: %s", ErrSmallCheckTypeNotValid, err)
+	}
+
 	return nil
 }
 
 func (h *Health) copy() (copied Health) {
 	return Health{
-		ServerAddress: h.ServerAddress,
+		ServerAddress:   h.ServerAddress,
-		TargetAddress: h.TargetAddress,
+		TargetAddresses: h.TargetAddresses,
-		ICMPTargetIP:  h.ICMPTargetIP,
+		ICMPTargetIPs:   gosettings.CopySlice(h.ICMPTargetIPs),
-		RestartVPN:    gosettings.CopyPointer(h.RestartVPN),
+		SmallCheckType:  h.SmallCheckType,
+		RestartVPN:      gosettings.CopyPointer(h.RestartVPN),
 	}
 }
 
@@ -53,15 +83,20 @@ func (h *Health) copy() (copied Health) {
 // settings.
 func (h *Health) OverrideWith(other Health) {
 	h.ServerAddress = gosettings.OverrideWithComparable(h.ServerAddress, other.ServerAddress)
-	h.TargetAddress = gosettings.OverrideWithComparable(h.TargetAddress, other.TargetAddress)
+	h.TargetAddresses = gosettings.OverrideWithSlice(h.TargetAddresses, other.TargetAddresses)
-	h.ICMPTargetIP = gosettings.OverrideWithComparable(h.ICMPTargetIP, other.ICMPTargetIP)
+	h.ICMPTargetIPs = gosettings.OverrideWithSlice(h.ICMPTargetIPs, other.ICMPTargetIPs)
+	h.SmallCheckType = gosettings.OverrideWithComparable(h.SmallCheckType, other.SmallCheckType)
 	h.RestartVPN = gosettings.OverrideWithPointer(h.RestartVPN, other.RestartVPN)
 }
 
 func (h *Health) SetDefaults() {
 	h.ServerAddress = gosettings.DefaultComparable(h.ServerAddress, "127.0.0.1:9999")
-	h.TargetAddress = gosettings.DefaultComparable(h.TargetAddress, "cloudflare.com:443")
+	h.TargetAddresses = gosettings.DefaultSlice(h.TargetAddresses, []string{"cloudflare.com:443", "github.com:443"})
-	h.ICMPTargetIP = gosettings.DefaultComparable(h.ICMPTargetIP, netip.IPv4Unspecified()) // use the VPN server IP
+	h.ICMPTargetIPs = gosettings.DefaultSlice(h.ICMPTargetIPs, []netip.Addr{
+		netip.AddrFrom4([4]byte{1, 1, 1, 1}),
+		netip.AddrFrom4([4]byte{8, 8, 8, 8}),
+	})
+	h.SmallCheckType = gosettings.DefaultComparable(h.SmallCheckType, "icmp")
 	h.RestartVPN = gosettings.DefaultPointer(h.RestartVPN, true)
 }
 
@@ -72,24 +107,37 @@ func (h Health) String() string {
 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)
+	targetAddrs := node.Appendf("Target addresses:")
-	icmpTarget := "VPN server IP"
+	for _, targetAddr := range h.TargetAddresses {
-	if !h.ICMPTargetIP.IsUnspecified() {
+		targetAddrs.Append(targetAddr)
-		icmpTarget = h.ICMPTargetIP.String()
+	}
+	switch h.SmallCheckType {
+	case "icmp":
+		icmpNode := node.Appendf("Small health check type: ICMP echo request")
+		if len(h.ICMPTargetIPs) == 1 && h.ICMPTargetIPs[0].IsUnspecified() {
+			icmpNode.Appendf("ICMP target IP: VPN server IP address")
+		} else {
+			icmpIPs := icmpNode.Appendf("ICMP target IPs:")
+			for _, ip := range h.ICMPTargetIPs {
+				icmpIPs.Append(ip.String())
+			}
+		}
+	case "dns":
+		node.Appendf("Small health check type: Plain DNS lookup over UDP")
 	}
-	node.Appendf("ICMP target IP: %s", icmpTarget)
 	node.Appendf("Restart VPN on healthcheck failure: %s", gosettings.BoolToYesNo(h.RestartVPN))
 	return node
 }
 
 func (h *Health) Read(r *reader.Reader) (err error) {
 	h.ServerAddress = r.String("HEALTH_SERVER_ADDRESS")
-	h.TargetAddress = r.String("HEALTH_TARGET_ADDRESS",
+	h.TargetAddresses = r.CSV("HEALTH_TARGET_ADDRESSES",
-		reader.RetroKeys("HEALTH_ADDRESS_TO_PING"))
+		reader.RetroKeys("HEALTH_ADDRESS_TO_PING", "HEALTH_TARGET_ADDRESS"))
-	h.ICMPTargetIP, err = r.NetipAddr("HEALTH_ICMP_TARGET_IP")
+	h.ICMPTargetIPs, err = r.CSVNetipAddresses("HEALTH_ICMP_TARGET_IPS", reader.RetroKeys("HEALTH_ICMP_TARGET_IP"))
 	if err != nil {
 		return err
 	}
+	h.SmallCheckType = r.String("HEALTH_SMALL_CHECK_TYPE")
 	h.RestartVPN, err = r.BoolPtr("HEALTH_RESTART_VPN")
 	if err != nil {
 		return err

internal/configuration/settings/openvpnselection.go

@@ -2,6 +2,7 @@ package settings
 
 import (
 	"fmt"
+	"net/netip"
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
@@ -24,6 +25,12 @@ type OpenVPNSelection struct {
 	// and can be udp or tcp. It cannot be the empty string
 	// in the internal state.
 	Protocol string `json:"protocol"`
+	// EndpointIP is the server endpoint IP address.
+	// If set, it overrides any IP address from the picked
+	// built-in server connection. To indicate it should
+	// not be used, it should be set to [netip.IPv4Unspecified].
+	// It can never be the zero value in the internal state.
+	EndpointIP netip.Addr `json:"endpoint_ip"`
 	// CustomPort is the OpenVPN server endpoint port.
 	// It can be set to 0 to indicate no custom port should
 	// be used. It cannot be nil in the internal state.
@@ -142,6 +149,7 @@ func (o *OpenVPNSelection) copy() (copied OpenVPNSelection) {
 	return OpenVPNSelection{
 		ConfFile:     gosettings.CopyPointer(o.ConfFile),
 		Protocol:     o.Protocol,
+		EndpointIP:   o.EndpointIP,
 		CustomPort:   gosettings.CopyPointer(o.CustomPort),
 		PIAEncPreset: gosettings.CopyPointer(o.PIAEncPreset),
 	}
@@ -151,12 +159,14 @@ func (o *OpenVPNSelection) overrideWith(other OpenVPNSelection) {
 	o.ConfFile = gosettings.OverrideWithPointer(o.ConfFile, other.ConfFile)
 	o.Protocol = gosettings.OverrideWithComparable(o.Protocol, other.Protocol)
 	o.CustomPort = gosettings.OverrideWithPointer(o.CustomPort, other.CustomPort)
+	o.EndpointIP = gosettings.OverrideWithValidator(o.EndpointIP, other.EndpointIP)
 	o.PIAEncPreset = gosettings.OverrideWithPointer(o.PIAEncPreset, other.PIAEncPreset)
 }
 
 func (o *OpenVPNSelection) setDefaults(vpnProvider string) {
 	o.ConfFile = gosettings.DefaultPointer(o.ConfFile, "")
 	o.Protocol = gosettings.DefaultComparable(o.Protocol, constants.UDP)
+	o.EndpointIP = gosettings.DefaultValidator(o.EndpointIP, netip.IPv4Unspecified())
 	o.CustomPort = gosettings.DefaultPointer(o.CustomPort, 0)
 
 	var defaultEncPreset string
@@ -174,6 +184,10 @@ func (o OpenVPNSelection) toLinesNode() (node *gotree.Node) {
 	node = gotree.New("OpenVPN server selection settings:")
 	node.Appendf("Protocol: %s", strings.ToUpper(o.Protocol))
 
+	if !o.EndpointIP.IsUnspecified() {
+		node.Appendf("Endpoint IP address: %s", o.EndpointIP)
+	}
+
 	if *o.CustomPort != 0 {
 		node.Appendf("Custom port: %d", *o.CustomPort)
 	}
@@ -194,6 +208,12 @@ func (o *OpenVPNSelection) read(r *reader.Reader) (err error) {
 
 	o.Protocol = r.String("OPENVPN_PROTOCOL", reader.RetroKeys("PROTOCOL"))
 
+	o.EndpointIP, err = r.NetipAddr("OPENVPN_ENDPOINT_IP",
+		reader.RetroKeys("OPENVPN_TARGET_IP", "VPN_ENDPOINT_IP"))
+	if err != nil {
+		return err
+	}
+
 	o.CustomPort, err = r.Uint16Ptr("OPENVPN_ENDPOINT_PORT",
 		reader.RetroKeys("PORT", "OPENVPN_PORT", "VPN_ENDPOINT_PORT"))
 	if err != nil {

internal/configuration/settings/serverselection.go

@@ -3,7 +3,6 @@ package settings
 import (
 	"errors"
 	"fmt"
-	"net/netip"
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
@@ -22,12 +21,6 @@ type ServerSelection struct {
 	// or 'wireguard'. It cannot be the empty string
 	// in the internal state.
 	VPN string `json:"vpn"`
-	// TargetIP is the server endpoint IP address to use.
-	// It will override any IP address from the picked
-	// built-in server. It cannot be the empty value in the internal
-	// state, and can be set to the unspecified address to indicate
-	// there is not target IP address to use.
-	TargetIP netip.Addr `json:"target_ip"`
 	// Countries is the list of countries to filter VPN servers with.
 	Countries []string `json:"countries"`
 	// Categories is the list of categories to filter VPN servers with.
@@ -299,7 +292,6 @@ func validateFeatureFilters(settings ServerSelection, vpnServiceProvider string)
 func (ss *ServerSelection) copy() (copied ServerSelection) {
 	return ServerSelection{
 		VPN:             ss.VPN,
-		TargetIP:        ss.TargetIP,
 		Countries:       gosettings.CopySlice(ss.Countries),
 		Categories:      gosettings.CopySlice(ss.Categories),
 		Regions:         gosettings.CopySlice(ss.Regions),
@@ -323,7 +315,6 @@ func (ss *ServerSelection) copy() (copied ServerSelection) {
 
 func (ss *ServerSelection) overrideWith(other ServerSelection) {
 	ss.VPN = gosettings.OverrideWithComparable(ss.VPN, other.VPN)
-	ss.TargetIP = gosettings.OverrideWithValidator(ss.TargetIP, other.TargetIP)
 	ss.Countries = gosettings.OverrideWithSlice(ss.Countries, other.Countries)
 	ss.Categories = gosettings.OverrideWithSlice(ss.Categories, other.Categories)
 	ss.Regions = gosettings.OverrideWithSlice(ss.Regions, other.Regions)
@@ -346,7 +337,6 @@ func (ss *ServerSelection) overrideWith(other ServerSelection) {
 
 func (ss *ServerSelection) setDefaults(vpnProvider string, portForwardingEnabled bool) {
 	ss.VPN = gosettings.DefaultComparable(ss.VPN, vpn.OpenVPN)
-	ss.TargetIP = gosettings.DefaultValidator(ss.TargetIP, netip.IPv4Unspecified())
 	ss.OwnedOnly = gosettings.DefaultPointer(ss.OwnedOnly, false)
 	ss.FreeOnly = gosettings.DefaultPointer(ss.FreeOnly, false)
 	ss.PremiumOnly = gosettings.DefaultPointer(ss.PremiumOnly, false)
@@ -368,9 +358,6 @@ func (ss ServerSelection) String() string {
 func (ss ServerSelection) toLinesNode() (node *gotree.Node) {
 	node = gotree.New("Server selection settings:")
 	node.Appendf("VPN type: %s", ss.VPN)
-	if !ss.TargetIP.IsUnspecified() {
-		node.Appendf("Target IP address: %s", ss.TargetIP)
-	}
 
 	if len(ss.Countries) > 0 {
 		node.Appendf("Countries: %s", strings.Join(ss.Countries, ", "))
@@ -461,12 +448,6 @@ func (ss *ServerSelection) read(r *reader.Reader,
 ) (err error) {
 	ss.VPN = vpnType
 
-	ss.TargetIP, err = r.NetipAddr("OPENVPN_ENDPOINT_IP",
-		reader.RetroKeys("OPENVPN_TARGET_IP", "VPN_ENDPOINT_IP"))
-	if err != nil {
-		return err
-	}
-
 	countriesRetroKeys := []string{"COUNTRY"}
 	if vpnProvider == providers.Cyberghost {
 		countriesRetroKeys = append(countriesRetroKeys, "REGION")

internal/configuration/settings/settings_test.go

@@ -57,8 +57,13 @@ func Test_Settings_String(t *testing.T) {
 |   └── Log level: INFO
 ├── Health settings:
 |   ├── Server listening address: 127.0.0.1:9999
-|   ├── Target address: cloudflare.com:443
+|   ├── Target addresses:
-|   ├── ICMP target IP: VPN server IP
+|   |   ├── cloudflare.com:443
+|   |   └── github.com:443
+|   ├── Small health check type: ICMP echo request
+|   |   └── ICMP target IPs:
+|   |       ├── 1.1.1.1
+|   |       └── 8.8.8.8
 |   └── Restart VPN on healthcheck failure: yes
 ├── Shadowsocks server settings:
 |   └── Enabled: no

internal/configuration/settings/updater.go

@@ -32,8 +32,8 @@ type Updater struct {
 	// Providers is the list of VPN service providers
 	// to update server information for.
 	Providers []string
-	// ProtonUsername is the username to authenticate with the Proton API.
+	// ProtonEmail is the email to authenticate with the Proton API.
-	ProtonUsername *string
+	ProtonEmail *string
 	// ProtonPassword is the password to authenticate with the Proton API.
 	ProtonPassword *string
 }
@@ -58,11 +58,11 @@ func (u Updater) Validate() (err error) {
 		}
 
 		if provider == providers.Protonvpn {
-			authenticatedAPI := *u.ProtonUsername != "" || *u.ProtonPassword != ""
+			authenticatedAPI := *u.ProtonEmail != "" || *u.ProtonPassword != ""
 			if authenticatedAPI {
 				switch {
-				case *u.ProtonUsername == "":
+				case *u.ProtonEmail == "":
-					return fmt.Errorf("%w", ErrUpdaterProtonUsernameMissing)
+					return fmt.Errorf("%w", ErrUpdaterProtonEmailMissing)
 				case *u.ProtonPassword == "":
 					return fmt.Errorf("%w", ErrUpdaterProtonPasswordMissing)
 				}
@@ -79,7 +79,7 @@ func (u *Updater) copy() (copied Updater) {
 		DNSAddress:     u.DNSAddress,
 		MinRatio:       u.MinRatio,
 		Providers:      gosettings.CopySlice(u.Providers),
-		ProtonUsername: gosettings.CopyPointer(u.ProtonUsername),
+		ProtonEmail:    gosettings.CopyPointer(u.ProtonEmail),
 		ProtonPassword: gosettings.CopyPointer(u.ProtonPassword),
 	}
 }
@@ -92,7 +92,7 @@ func (u *Updater) overrideWith(other Updater) {
 	u.DNSAddress = gosettings.OverrideWithComparable(u.DNSAddress, other.DNSAddress)
 	u.MinRatio = gosettings.OverrideWithComparable(u.MinRatio, other.MinRatio)
 	u.Providers = gosettings.OverrideWithSlice(u.Providers, other.Providers)
-	u.ProtonUsername = gosettings.OverrideWithPointer(u.ProtonUsername, other.ProtonUsername)
+	u.ProtonEmail = gosettings.OverrideWithPointer(u.ProtonEmail, other.ProtonEmail)
 	u.ProtonPassword = gosettings.OverrideWithPointer(u.ProtonPassword, other.ProtonPassword)
 }
 
@@ -110,7 +110,7 @@ func (u *Updater) SetDefaults(vpnProvider string) {
 	}
 
 	// Set these to empty strings to avoid nil pointer panics
-	u.ProtonUsername = gosettings.DefaultPointer(u.ProtonUsername, "")
+	u.ProtonEmail = gosettings.DefaultPointer(u.ProtonEmail, "")
 	u.ProtonPassword = gosettings.DefaultPointer(u.ProtonPassword, "")
 }
 
@@ -129,7 +129,7 @@ func (u Updater) toLinesNode() (node *gotree.Node) {
 	node.Appendf("Minimum ratio: %.1f", u.MinRatio)
 	node.Appendf("Providers to update: %s", strings.Join(u.Providers, ", "))
 	if slices.Contains(u.Providers, providers.Protonvpn) {
-		node.Appendf("Proton API username: %s", *u.ProtonUsername)
+		node.Appendf("Proton API email: %s", *u.ProtonEmail)
 		node.Appendf("Proton API password: %s", gosettings.ObfuscateKey(*u.ProtonPassword))
 	}
 
@@ -154,11 +154,13 @@ func (u *Updater) read(r *reader.Reader) (err error) {
 
 	u.Providers = r.CSV("UPDATER_VPN_SERVICE_PROVIDERS")
 
-	u.ProtonUsername = r.Get("UPDATER_PROTONVPN_USERNAME")
+	u.ProtonEmail = r.Get("UPDATER_PROTONVPN_EMAIL")
-	if u.ProtonUsername != nil {
+	if u.ProtonEmail == nil {
-		// Enforce to use the username not the email address
+		protonUsername := r.String("UPDATER_PROTONVPN_USERNAME", reader.IsRetro("UPDATER_PROTONVPN_EMAIL"))
-		*u.ProtonUsername = strings.TrimSuffix(*u.ProtonUsername, "@protonmail.com")
+		if protonUsername != "" {
-		*u.ProtonUsername = strings.TrimSuffix(*u.ProtonUsername, "@proton.me")
+			protonEmail := protonUsername + "@protonmail.com"
+			u.ProtonEmail = &protonEmail
+		}
 	}
 	u.ProtonPassword = r.Get("UPDATER_PROTONVPN_PASSWORD")
 

internal/configuration/settings/wireguardselection.go

@@ -14,11 +14,11 @@ import (
 
 type WireguardSelection struct {
 	// EndpointIP is the server endpoint IP address.
-	// It is only used with VPN providers generating Wireguard
+	// It is notably required with the custom provider.
-	// configurations specific to each server and user.
+	// Otherwise it overrides any IP address from the picked
-	// To indicate it should not be used, it should be set
+	// built-in server connection. To indicate it should
-	// to netip.IPv4Unspecified(). It can never be the zero value
+	// not be used, it should be set to [netip.IPv4Unspecified].
-	// in the internal state.
+	// It can never be the zero value in the internal state.
 	EndpointIP netip.Addr `json:"endpoint_ip"`
 	// EndpointPort is a the server port to use for the VPN server.
 	// It is optional for VPN providers IVPN, Mullvad, Surfshark

internal/healthcheck/checker.go

@@ -16,16 +16,16 @@ import (
 )
 
 type Checker struct {
-	tlsDialAddr string
+	tlsDialAddrs   []string
-	dialer      *net.Dialer
+	dialer         *net.Dialer
-	echoer      *icmp.Echoer
+	echoer         *icmp.Echoer
-	dnsClient   *dns.Client
+	dnsClient      *dns.Client
-	logger      Logger
+	logger         Logger
-	icmpTarget  netip.Addr
+	icmpTargetIPs  []netip.Addr
-	configMutex sync.Mutex
+	smallCheckType string
+	configMutex    sync.Mutex
 
 	icmpNotPermitted bool
-	smallCheckName   string
 
 	// Internal periodic service signals
 	stop context.CancelFunc
@@ -45,35 +45,37 @@ func NewChecker(logger Logger) *Checker {
 	}
 }
 
-// SetConfig sets the TCP+TLS dial address and the ICMP echo IP address
+// SetConfig sets the TCP+TLS dial addresses, the ICMP echo IP address
-// to target by the [Checker].
+// to target and the desired small check type (dns or icmp).
 // This function MUST be called before calling [Checker.Start].
-func (c *Checker) SetConfig(tlsDialAddr string, icmpTarget netip.Addr) {
+func (c *Checker) SetConfig(tlsDialAddrs []string, icmpTargets []netip.Addr,
+	smallCheckType string,
+) {
 	c.configMutex.Lock()
 	defer c.configMutex.Unlock()
-	c.tlsDialAddr = tlsDialAddr
+	c.tlsDialAddrs = tlsDialAddrs
-	c.icmpTarget = icmpTarget
+	c.icmpTargetIPs = icmpTargets
+	c.smallCheckType = smallCheckType
 }
 
-// Start starts the checker by first running a blocking 2s-timed TCP+TLS check,
+// Start starts the checker by first running a blocking 6s-timed TCP+TLS check,
 // and, on success, starts the periodic checks in a separate goroutine:
-// - a "small" ICMP echo check every 15 seconds
+// - a "small" ICMP echo check every minute
 // - a "full" TCP+TLS check every 5 minutes
 // It returns a channel `runError` that receives an error (nil or not) when a periodic check is performed.
 // It returns an error if the initial TCP+TLS check fails.
 // The Checker has to be ultimately stopped by calling [Checker.Stop].
 func (c *Checker) Start(ctx context.Context) (runError <-chan error, err error) {
-	if c.tlsDialAddr == "" || c.icmpTarget.IsUnspecified() {
+	if len(c.tlsDialAddrs) == 0 || len(c.icmpTargetIPs) == 0 || c.smallCheckType == "" {
 		panic("call Checker.SetConfig with non empty values before Checker.Start")
 	}
 
-	// connection isn't under load yet when the checker starts, so a short
+	if c.icmpNotPermitted {
-	// 6 seconds timeout suffices and provides quick enough feedback that
+		// restore forced check type to dns if icmp was found to be not permitted
-	// the new connection is not working.
+		c.smallCheckType = smallCheckDNS
-	const timeout = 6 * time.Second
+	}
-	tcpTLSCheckCtx, tcpTLSCheckCancel := context.WithTimeout(ctx, timeout)
+
-	err = tcpTLSCheck(tcpTLSCheckCtx, c.dialer, c.tlsDialAddr)
+	err = c.startupCheck(ctx)
-	tcpTLSCheckCancel()
 	if err != nil {
 		return nil, fmt.Errorf("startup check: %w", err)
 	}
@@ -83,7 +85,6 @@ func (c *Checker) Start(ctx context.Context) (runError <-chan error, err error)
 	c.stop = cancel
 	done := make(chan struct{})
 	c.done = done
-	c.smallCheckName = "ICMP echo"
 	const smallCheckPeriod = time.Minute
 	smallCheckTimer := time.NewTimer(smallCheckPeriod)
 	const fullCheckPeriod = 5 * time.Minute
@@ -123,13 +124,16 @@ func (c *Checker) Start(ctx context.Context) (runError <-chan error, err error)
 func (c *Checker) Stop() error {
 	c.stop()
 	<-c.done
-	c.icmpTarget = netip.Addr{}
+	c.tlsDialAddrs = nil
+	c.icmpTargetIPs = nil
+	c.smallCheckType = ""
 	return nil
 }
 
 func (c *Checker) smallPeriodicCheck(ctx context.Context) error {
 	c.configMutex.Lock()
-	ip := c.icmpTarget
+	icmpTargetIPs := make([]netip.Addr, len(c.icmpTargetIPs))
+	copy(icmpTargetIPs, c.icmpTargetIPs)
 	c.configMutex.Unlock()
 	tryTimeouts := []time.Duration{
 		5 * time.Second,
@@ -143,28 +147,31 @@ func (c *Checker) smallPeriodicCheck(ctx context.Context) error {
 		15 * time.Second,
 		30 * time.Second,
 	}
-	check := func(ctx context.Context) error {
+	check := func(ctx context.Context, try int) error {
-		if c.icmpNotPermitted {
+		if c.smallCheckType == smallCheckDNS {
 			return c.dnsClient.Check(ctx)
 		}
+		ip := icmpTargetIPs[try%len(icmpTargetIPs)]
 		err := c.echoer.Echo(ctx, ip)
 		if errors.Is(err, icmp.ErrNotPermitted) {
 			c.icmpNotPermitted = true
-			c.smallCheckName = "plain DNS over UDP"
+			c.smallCheckType = smallCheckDNS
-			c.logger.Infof("%s; permanently falling back to %s checks.", c.smallCheckName, err)
+			c.logger.Infof("%s; permanently falling back to %s checks",
+				smallCheckTypeToString(c.smallCheckType), err)
 			return c.dnsClient.Check(ctx)
 		}
 		return err
 	}
-	return withRetries(ctx, tryTimeouts, c.logger, c.smallCheckName, check)
+	return withRetries(ctx, tryTimeouts, c.logger, smallCheckTypeToString(c.smallCheckType), check)
 }
 
 func (c *Checker) fullPeriodicCheck(ctx context.Context) error {
 	// 20s timeout in case the connection is under stress
 	// See https://github.com/qdm12/gluetun/issues/2270
 	tryTimeouts := []time.Duration{10 * time.Second, 15 * time.Second, 30 * time.Second}
-	check := func(ctx context.Context) error {
+	check := func(ctx context.Context, try int) error {
-		return tcpTLSCheck(ctx, c.dialer, c.tlsDialAddr)
+		tlsDialAddr := c.tlsDialAddrs[try%len(c.tlsDialAddrs)]
+		return tcpTLSCheck(ctx, c.dialer, tlsDialAddr)
 	}
 	return withRetries(ctx, tryTimeouts, c.logger, "TCP+TLS dial", check)
 }
@@ -226,18 +233,18 @@ func makeAddressToDial(address string) (addressToDial string, err error) {
 var ErrAllCheckTriesFailed = errors.New("all check tries failed")
 
 func withRetries(ctx context.Context, tryTimeouts []time.Duration,
-	logger Logger, checkName string, check func(ctx context.Context) error,
+	logger Logger, checkName string, check func(ctx context.Context, try int) error,
 ) error {
 	maxTries := len(tryTimeouts)
 	type errData struct {
-		err      error
+		err        error
-		duration time.Duration
+		durationMS int64
 	}
 	errs := make([]errData, maxTries)
 	for i, timeout := range tryTimeouts {
 		start := time.Now()
 		checkCtx, cancel := context.WithTimeout(ctx, timeout)
-		err := check(checkCtx)
+		err := check(checkCtx, i)
 		cancel()
 		switch {
 		case err == nil:
@@ -247,12 +254,73 @@ func withRetries(ctx context.Context, tryTimeouts []time.Duration,
 		}
 		logger.Debugf("%s attempt %d/%d failed: %s", checkName, i+1, maxTries, err)
 		errs[i].err = err
-		errs[i].duration = time.Since(start)
+		errs[i].durationMS = time.Since(start).Round(time.Millisecond).Milliseconds()
 	}
 
 	errStrings := make([]string, len(errs))
 	for i, err := range errs {
-		errStrings[i] = fmt.Sprintf("attempt %d (%s): %s", i+1, err.duration, err.err)
+		errStrings[i] = fmt.Sprintf("attempt %d (%dms): %s", i+1, err.durationMS, err.err)
 	}
 	return fmt.Errorf("%w: %s", ErrAllCheckTriesFailed, strings.Join(errStrings, ", "))
 }
+
+func (c *Checker) startupCheck(ctx context.Context) error {
+	// connection isn't under load yet when the checker starts, so a short
+	// 6 seconds timeout suffices and provides quick enough feedback that
+	// the new connection is not working. However, since the addresses to dial
+	// may be multiple, we run the check in parallel. If any succeeds, the check passes.
+	// This is to prevent false negatives at startup, if one of the addresses is down
+	// for external reasons.
+	const timeout = 6 * time.Second
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+	errCh := make(chan error)
+
+	for _, address := range c.tlsDialAddrs {
+		go func(addr string) {
+			err := tcpTLSCheck(ctx, c.dialer, addr)
+			errCh <- err
+		}(address)
+	}
+
+	errs := make([]error, 0, len(c.tlsDialAddrs))
+	success := false
+	for range c.tlsDialAddrs {
+		err := <-errCh
+		if err == nil {
+			success = true
+			cancel()
+			continue
+		} else if success {
+			continue // ignore canceled errors after success
+		}
+
+		c.logger.Debugf("startup check parallel attempt failed: %s", err)
+		errs = append(errs, err)
+	}
+	if success {
+		return nil
+	}
+
+	errStrings := make([]string, len(errs))
+	for i, err := range errs {
+		errStrings[i] = fmt.Sprintf("parallel attempt %d/%d failed: %s", i+1, len(errs), err)
+	}
+	return fmt.Errorf("%w: %s", ErrAllCheckTriesFailed, strings.Join(errStrings, ", "))
+}
+
+const (
+	smallCheckDNS  = "dns"
+	smallCheckICMP = "icmp"
+)
+
+func smallCheckTypeToString(smallCheckType string) string {
+	switch smallCheckType {
+	case smallCheckICMP:
+		return "ICMP echo"
+	case smallCheckDNS:
+		return "plain DNS over UDP"
+	default:
+		panic("unknown small check type: " + smallCheckType)
+	}
+}

internal/healthcheck/checker_test.go

@@ -18,11 +18,11 @@ func Test_Checker_fullcheck(t *testing.T) {
 		t.Parallel()
 
 		dialer := &net.Dialer{}
-		const address = "cloudflare.com:443"
+		addresses := []string{"badaddress:9876", "cloudflare.com:443", "google.com:443"}
 
 		checker := &Checker{
-			dialer:      dialer,
+			dialer:       dialer,
-			tlsDialAddr: address,
+			tlsDialAddrs: addresses,
 		}
 
 		canceledCtx, cancel := context.WithCancel(context.Background())
@@ -52,8 +52,8 @@ func Test_Checker_fullcheck(t *testing.T) {
 
 		dialer := &net.Dialer{}
 		checker := &Checker{
-			dialer:      dialer,
+			dialer:       dialer,
-			tlsDialAddr: listeningAddress.String(),
+			tlsDialAddrs: []string{listeningAddress.String()},
 		}
 
 		err = checker.fullPeriodicCheck(ctx)

internal/healthcheck/dns/dns.go

@@ -56,10 +56,10 @@ func (c *Client) Check(ctx context.Context) error {
 	switch {
 	case err != nil:
 		c.dnsIPIndex = (c.dnsIPIndex + 1) % len(c.serverAddrs)
-		return err
+		return fmt.Errorf("with DNS server %s: %w", dnsAddr, err)
 	case len(ips) == 0:
 		c.dnsIPIndex = (c.dnsIPIndex + 1) % len(c.serverAddrs)
-		return fmt.Errorf("%w", ErrLookupNoIPs)
+		return fmt.Errorf("with DNS server %s: %w", dnsAddr, ErrLookupNoIPs)
 	default:
 		return nil
 	}

internal/healthcheck/icmp/echo.go

@@ -82,20 +82,20 @@ func (i *Echoer) Echo(ctx context.Context, ip netip.Addr) (err error) {
 		if strings.HasSuffix(err.Error(), "sendto: operation not permitted") {
 			err = fmt.Errorf("%w", ErrNotPermitted)
 		}
-		return fmt.Errorf("writing ICMP message: %w", err)
+		return fmt.Errorf("writing ICMP message to %s: %w", ip, err)
 	}
 
 	receivedData, err := receiveEchoReply(conn, id, i.buffer, ipVersion, i.logger)
 	if err != nil {
 		if errors.Is(err, net.ErrClosed) && ctx.Err() != nil {
-			return fmt.Errorf("%w", ErrTimedOut)
+			return fmt.Errorf("%w from %s", ErrTimedOut, ip)
 		}
-		return fmt.Errorf("receiving ICMP echo reply: %w", err)
+		return fmt.Errorf("receiving ICMP echo reply from %s: %w", ip, err)
 	}
 
 	sentData := message.Body.(*icmp.Echo).Data //nolint:forcetypeassert
 	if !bytes.Equal(receivedData, sentData) {
-		return fmt.Errorf("%w: sent %x and received %x", ErrICMPEchoDataMismatch, sentData, receivedData)
+		return fmt.Errorf("%w: sent %x to %s and received %x", ErrICMPEchoDataMismatch, sentData, ip, receivedData)
 	}
 
 	return nil

internal/provider/protonvpn/provider.go

@@ -18,12 +18,12 @@ type Provider struct {
 
 func New(storage common.Storage, randSource rand.Source,
 	client *http.Client, updaterWarner common.Warner,
-	username, password string,
+	email, password string,
 ) *Provider {
 	return &Provider{
 		storage:    storage,
 		randSource: randSource,
-		Fetcher:    updater.New(client, updaterWarner, username, password),
+		Fetcher:    updater.New(client, updaterWarner, email, password),
 	}
 }
 

internal/provider/protonvpn/updater/api.go

@@ -76,7 +76,7 @@ func (c *apiClient) setHeaders(request *http.Request, cookie cookie) {
 
 // authenticate performs the full Proton authentication flow
 // to obtain an authenticated cookie (uid, token and session ID).
-func (c *apiClient) authenticate(ctx context.Context, username, password string,
+func (c *apiClient) authenticate(ctx context.Context, email, password string,
 ) (authCookie cookie, err error) {
 	sessionID, err := c.getSessionID(ctx)
 	if err != nil {
@@ -98,8 +98,8 @@ func (c *apiClient) authenticate(ctx context.Context, username, password string,
 		token:     cookieToken,
 		sessionID: sessionID,
 	}
-	modulusPGPClearSigned, serverEphemeralBase64, saltBase64,
+	username, modulusPGPClearSigned, serverEphemeralBase64, saltBase64,
-		srpSessionHex, version, err := c.authInfo(ctx, username, unauthCookie)
+		srpSessionHex, version, err := c.authInfo(ctx, email, unauthCookie)
 	if err != nil {
 		return cookie{}, fmt.Errorf("getting auth information: %w", err)
 	}
@@ -118,7 +118,7 @@ func (c *apiClient) authenticate(ctx context.Context, username, password string,
 		return cookie{}, fmt.Errorf("generating SRP proofs: %w", err)
 	}
 
-	authCookie, err = c.auth(ctx, unauthCookie, username, srpSessionHex, proofs)
+	authCookie, err = c.auth(ctx, unauthCookie, email, srpSessionHex, proofs)
 	if err != nil {
 		return cookie{}, fmt.Errorf("authentifying: %w", err)
 	}
@@ -299,48 +299,45 @@ func (c *apiClient) cookieToken(ctx context.Context, sessionID, tokenType, acces
 	return "", fmt.Errorf("%w", ErrAuthCookieNotFound)
 }
 
-var (
+var ErrUsernameDoesNotExist = errors.New("username does not exist")
-	ErrUsernameDoesNotExist = errors.New("username does not exist")
-	ErrUsernameMismatch     = errors.New("username in response does not match request username")
-)
 
 // authInfo fetches SRP parameters for the account.
-func (c *apiClient) authInfo(ctx context.Context, username string, unauthCookie cookie) (
+func (c *apiClient) authInfo(ctx context.Context, email string, unauthCookie cookie) (
-	modulusPGPClearSigned, serverEphemeralBase64, saltBase64, srpSessionHex string,
+	username, modulusPGPClearSigned, serverEphemeralBase64, saltBase64, srpSessionHex string,
 	version int, err error,
 ) {
 	type requestBodySchema struct {
-		Intent   string `json:"Intent"`   // "Proton"
+		Intent   string `json:"Intent"` // "Proton"
-		Username string `json:"Username"` // username without @domain.com
+		Username string `json:"Username"`
 	}
 	requestBody := requestBodySchema{
 		Intent:   "Proton",
-		Username: username,
+		Username: email,
 	}
 
 	buffer := bytes.NewBuffer(nil)
 	encoder := json.NewEncoder(buffer)
 	if err := encoder.Encode(requestBody); err != nil {
-		return "", "", "", "", 0, fmt.Errorf("encoding request body: %w", err)
+		return "", "", "", "", "", 0, fmt.Errorf("encoding request body: %w", err)
 	}
 
 	request, err := http.NewRequestWithContext(ctx, http.MethodPost, c.apiURLBase+"/core/v4/auth/info", buffer)
 	if err != nil {
-		return "", "", "", "", 0, fmt.Errorf("creating request: %w", err)
+		return "", "", "", "", "", 0, fmt.Errorf("creating request: %w", err)
 	}
 	c.setHeaders(request, unauthCookie)
 
 	response, err := c.httpClient.Do(request)
 	if err != nil {
-		return "", "", "", "", 0, err
+		return "", "", "", "", "", 0, err
 	}
 	defer response.Body.Close()
 
 	responseBody, err := io.ReadAll(response.Body)
 	if err != nil {
-		return "", "", "", "", 0, fmt.Errorf("reading response body: %w", err)
+		return "", "", "", "", "", 0, fmt.Errorf("reading response body: %w", err)
 	} else if response.StatusCode != http.StatusOK {
-		return "", "", "", "", 0, buildError(response.StatusCode, responseBody)
+		return "", "", "", "", "", 0, buildError(response.StatusCode, responseBody)
 	}
 
 	var info struct {
@@ -354,32 +351,30 @@ func (c *apiClient) authInfo(ctx context.Context, username string, unauthCookie
 	}
 	err = json.Unmarshal(responseBody, &info)
 	if err != nil {
-		return "", "", "", "", 0, fmt.Errorf("decoding response body: %w", err)
+		return "", "", "", "", "", 0, fmt.Errorf("decoding response body: %w", err)
 	}
 
 	const successCode = 1000
 	switch {
 	case info.Code != successCode:
-		return "", "", "", "", 0, fmt.Errorf("%w: expected %d got %d",
+		return "", "", "", "", "", 0, fmt.Errorf("%w: expected %d got %d",
 			ErrCodeNotSuccess, successCode, info.Code)
 	case info.Modulus == "":
-		return "", "", "", "", 0, fmt.Errorf("%w: modulus is empty", ErrDataFieldMissing)
+		return "", "", "", "", "", 0, fmt.Errorf("%w: modulus is empty", ErrDataFieldMissing)
 	case info.ServerEphemeral == "":
-		return "", "", "", "", 0, fmt.Errorf("%w: server ephemeral is empty", ErrDataFieldMissing)
+		return "", "", "", "", "", 0, fmt.Errorf("%w: server ephemeral is empty", ErrDataFieldMissing)
 	case info.Salt == "":
-		return "", "", "", "", 0, fmt.Errorf("%w (salt data field is empty)", ErrUsernameDoesNotExist)
+		return "", "", "", "", "", 0, fmt.Errorf("%w (salt data field is empty)", ErrUsernameDoesNotExist)
 	case info.SRPSession == "":
-		return "", "", "", "", 0, fmt.Errorf("%w: SRP session is empty", ErrDataFieldMissing)
+		return "", "", "", "", "", 0, fmt.Errorf("%w: SRP session is empty", ErrDataFieldMissing)
-
+	case info.Username == "":
-	case !strings.EqualFold(info.Username, username):
+		return "", "", "", "", "", 0, fmt.Errorf("%w: username is empty", ErrDataFieldMissing)
-		return "", "", "", "", 0, fmt.Errorf("%w: expected %s got %s",
-			ErrUsernameMismatch, username, info.Username)
 	case info.Version == nil:
-		return "", "", "", "", 0, fmt.Errorf("%w: version is missing", ErrDataFieldMissing)
+		return "", "", "", "", "", 0, fmt.Errorf("%w: version is missing", ErrDataFieldMissing)
 	}
 
 	version = int(*info.Version) //nolint:gosec
-	return info.Modulus, info.ServerEphemeral, info.Salt,
+	return info.Username, info.Modulus, info.ServerEphemeral, info.Salt,
 		info.SRPSession, version, nil
 }
 

internal/provider/protonvpn/updater/servers.go

@@ -14,8 +14,8 @@ func (u *Updater) FetchServers(ctx context.Context, minServers int) (
 	servers []models.Server, err error,
 ) {
 	switch {
-	case u.username == "":
+	case u.email == "":
-		return nil, fmt.Errorf("%w: username is empty", common.ErrCredentialsMissing)
+		return nil, fmt.Errorf("%w: email is empty", common.ErrCredentialsMissing)
 	case u.password == "":
 		return nil, fmt.Errorf("%w: password is empty", common.ErrCredentialsMissing)
 	}
@@ -25,7 +25,7 @@ func (u *Updater) FetchServers(ctx context.Context, minServers int) (
 		return nil, fmt.Errorf("creating API client: %w", err)
 	}
 
-	cookie, err := apiClient.authenticate(ctx, u.username, u.password)
+	cookie, err := apiClient.authenticate(ctx, u.email, u.password)
 	if err != nil {
 		return nil, fmt.Errorf("authentifying with Proton: %w", err)
 	}

internal/provider/protonvpn/updater/updater.go

@@ -8,15 +8,15 @@ import (
 
 type Updater struct {
 	client   *http.Client
-	username string
+	email    string
 	password string
 	warner   common.Warner
 }
 
-func New(client *http.Client, warner common.Warner, username, password string) *Updater {
+func New(client *http.Client, warner common.Warner, email, password string) *Updater {
 	return &Updater{
 		client:   client,
-		username: username,
+		email:    email,
 		password: password,
 		warner:   warner,
 	}

internal/provider/providers.go

@@ -75,7 +75,7 @@ func NewProviders(storage Storage, timeNow func() time.Time,
 		providers.Privado:               privado.New(storage, randSource, ipFetcher, unzipper, updaterWarner, parallelResolver),
 		providers.PrivateInternetAccess: privateinternetaccess.New(storage, randSource, timeNow, client),
 		providers.Privatevpn:            privatevpn.New(storage, randSource, unzipper, updaterWarner, parallelResolver),
-		providers.Protonvpn:             protonvpn.New(storage, randSource, client, updaterWarner, *credentials.ProtonUsername, *credentials.ProtonPassword),
+		providers.Protonvpn:             protonvpn.New(storage, randSource, client, updaterWarner, *credentials.ProtonEmail, *credentials.ProtonPassword),
 		providers.Purevpn:               purevpn.New(storage, randSource, ipFetcher, unzipper, updaterWarner, parallelResolver),
 		providers.SlickVPN:              slickvpn.New(storage, randSource, client, updaterWarner, parallelResolver),
 		providers.Surfshark:             surfshark.New(storage, randSource, client, unzipper, updaterWarner, parallelResolver),

internal/provider/utils/pick.go

@@ -26,16 +26,25 @@ func pickConnection(connections []models.Connection,
 		return connection, ErrNoConnectionToPickFrom
 	}
 
-	targetIPSet := selection.TargetIP.IsValid() && !selection.TargetIP.IsUnspecified()
+	var targetIP netip.Addr
+	switch selection.VPN {
+	case vpn.OpenVPN:
+		targetIP = selection.OpenVPN.EndpointIP
+	case vpn.Wireguard:
+		targetIP = selection.Wireguard.EndpointIP
+	default:
+		panic("unknown VPN type: " + selection.VPN)
+	}
+	targetIPSet := targetIP.IsValid() && !targetIP.IsUnspecified()
 
 	if targetIPSet && selection.VPN == vpn.Wireguard {
 		// we need the right public key
-		return getTargetIPConnection(connections, selection.TargetIP)
+		return getTargetIPConnection(connections, targetIP)
 	}
 
 	connection = pickRandomConnection(connections, randSource)
 	if targetIPSet {
-		connection.IP = selection.TargetIP
+		connection.IP = targetIP
 	}
 
 	return connection, nil

internal/storage/flush.go

@@ -21,6 +21,9 @@ func (s *Storage) FlushToFile(path string) error {
 // flushToFile flushes the merged servers data to the file
 // specified by path, as indented JSON. It is not thread-safe.
 func (s *Storage) flushToFile(path string) error {
+	if path == "" {
+		return nil // no file to write to
+	}
 	const permission = 0o644
 	dirPath := filepath.Dir(path)
 	if err := os.MkdirAll(dirPath, permission); err != nil {

internal/storage/formatting.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
 	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/constants/vpn"
 )
 
 func commaJoin(slice []string) string {
@@ -148,9 +149,13 @@ func noServerFoundError(selection settings.ServerSelection) (err error) {
 		messageParts = append(messageParts, "tor only")
 	}
 
-	if selection.TargetIP.IsValid() {
+	targetIP := selection.OpenVPN.EndpointIP
+	if selection.VPN == vpn.Wireguard {
+		targetIP = selection.Wireguard.EndpointIP
+	}
+	if targetIP.IsValid() {
 		messageParts = append(messageParts,
-			"target ip address "+selection.TargetIP.String())
+			"target ip address "+targetIP.String())
 	}
 
 	message := "for " + strings.Join(messageParts, "; ")

internal/vpn/interfaces.go

@@ -101,7 +101,7 @@ type CmdStarter interface {
 }
 
 type HealthChecker interface {
-	SetConfig(tlsDialAddr string, icmpTarget netip.Addr)
+	SetConfig(tlsDialAddrs []string, icmpTargetIPs []netip.Addr, smallCheckType string)
 	Start(ctx context.Context) (runError <-chan error, err error)
 	Stop() error
 }

internal/vpn/tunnelup.go

@@ -31,11 +31,12 @@ func (l *Loop) onTunnelUp(ctx, loopCtx context.Context, data tunnelUpData) {
 		}
 	}
 
-	icmpTarget := l.healthSettings.ICMPTargetIP
+	icmpTargetIPs := l.healthSettings.ICMPTargetIPs
-	if icmpTarget.IsUnspecified() {
+	if len(icmpTargetIPs) == 1 && icmpTargetIPs[0].IsUnspecified() {
-		icmpTarget = data.serverIP
+		icmpTargetIPs = []netip.Addr{data.serverIP}
 	}
-	l.healthChecker.SetConfig(l.healthSettings.TargetAddress, icmpTarget)
+	l.healthChecker.SetConfig(l.healthSettings.TargetAddresses, icmpTargetIPs,
+		l.healthSettings.SmallCheckType)
 
 	healthErrCh, err := l.healthChecker.Start(ctx)
 	l.healthServer.SetError(err)