Rewrite of the entrypoint in Golang (#71)

- General improvements
    - Parallel download of only needed files at start
    - Prettier console output with all streams merged (openvpn, unbound, shadowsocks etc.)
    - Simplified Docker final image
    - Faster bootup
- DNS over TLS
    - Finer grain blocking at DNS level: malicious, ads and surveillance
    - Choose your DNS over TLS providers
    - Ability to use multiple DNS over TLS providers for DNS split horizon
    - Environment variables for DNS logging
    - DNS block lists needed are downloaded and built automatically at start, in parallel
- PIA
    - A random region is selected if the REGION parameter is left empty (thanks @rorph for your PR)
    - Routing and iptables adjusted so it can work as a Kubernetes pod sidecar (thanks @rorph for your PR)

internal/dns/roots_test.go

@@ -0,0 +1,144 @@
+package dns
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	filesMocks "github.com/qdm12/golibs/files/mocks"
+	loggingMocks "github.com/qdm12/golibs/logging/mocks"
+	networkMocks "github.com/qdm12/golibs/network/mocks"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+
+	"github.com/qdm12/private-internet-access-docker/internal/constants"
+)
+
+func Test_DownloadRootHints(t *testing.T) {
+	t.Parallel()
+	tests := map[string]struct {
+		content   []byte
+		status    int
+		clientErr error
+		writeErr  error
+		err       error
+	}{
+		"no data": {
+			status: http.StatusOK,
+		},
+		"bad status": {
+			status: http.StatusBadRequest,
+			err:    fmt.Errorf("HTTP status code is 400 for https://raw.githubusercontent.com/qdm12/files/master/named.root.updated"),
+		},
+		"client error": {
+			clientErr: fmt.Errorf("error"),
+			err:       fmt.Errorf("error"),
+		},
+		"write error": {
+			status:   http.StatusOK,
+			writeErr: fmt.Errorf("error"),
+			err:      fmt.Errorf("error"),
+		},
+		"data": {
+			content: []byte("content"),
+			status:  http.StatusOK,
+		},
+	}
+	for name, tc := range tests {
+		tc := tc
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			logger := &loggingMocks.Logger{}
+			logger.On("Info", "%s: downloading root hints from %s", logPrefix, constants.NamedRootURL).Once()
+			client := &networkMocks.Client{}
+			client.On("GetContent", string(constants.NamedRootURL)).
+				Return(tc.content, tc.status, tc.clientErr).Once()
+			fileManager := &filesMocks.FileManager{}
+			if tc.clientErr == nil && tc.status == http.StatusOK {
+				fileManager.On(
+					"WriteToFile",
+					string(constants.RootHints),
+					tc.content,
+					mock.AnythingOfType("files.WriteOptionSetter"),
+					mock.AnythingOfType("files.WriteOptionSetter")).
+					Return(tc.writeErr).Once()
+			}
+			c := &configurator{logger: logger, client: client, fileManager: fileManager}
+			err := c.DownloadRootHints(1000, 1000)
+			if tc.err != nil {
+				require.Error(t, err)
+				assert.Equal(t, tc.err.Error(), err.Error())
+			} else {
+				assert.NoError(t, err)
+			}
+			logger.AssertExpectations(t)
+			client.AssertExpectations(t)
+			fileManager.AssertExpectations(t)
+		})
+	}
+}
+
+func Test_DownloadRootKey(t *testing.T) {
+	t.Parallel()
+	tests := map[string]struct {
+		content   []byte
+		status    int
+		clientErr error
+		writeErr  error
+		err       error
+	}{
+		"no data": {
+			status: http.StatusOK,
+		},
+		"bad status": {
+			status: http.StatusBadRequest,
+			err:    fmt.Errorf("HTTP status code is 400 for https://raw.githubusercontent.com/qdm12/files/master/root.key.updated"),
+		},
+		"client error": {
+			clientErr: fmt.Errorf("error"),
+			err:       fmt.Errorf("error"),
+		},
+		"write error": {
+			status:   http.StatusOK,
+			writeErr: fmt.Errorf("error"),
+			err:      fmt.Errorf("error"),
+		},
+		"data": {
+			content: []byte("content"),
+			status:  http.StatusOK,
+		},
+	}
+	for name, tc := range tests {
+		tc := tc
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+			logger := &loggingMocks.Logger{}
+			logger.On("Info", "%s: downloading root key from %s", logPrefix, constants.RootKeyURL).Once()
+			client := &networkMocks.Client{}
+			client.On("GetContent", string(constants.RootKeyURL)).
+				Return(tc.content, tc.status, tc.clientErr).Once()
+			fileManager := &filesMocks.FileManager{}
+			if tc.clientErr == nil && tc.status == http.StatusOK {
+				fileManager.On(
+					"WriteToFile",
+					string(constants.RootKey),
+					tc.content,
+					mock.AnythingOfType("files.WriteOptionSetter"),
+					mock.AnythingOfType("files.WriteOptionSetter"),
+				).Return(tc.writeErr).Once()
+			}
+			c := &configurator{logger: logger, client: client, fileManager: fileManager}
+			err := c.DownloadRootKey(1000, 1001)
+			if tc.err != nil {
+				require.Error(t, err)
+				assert.Equal(t, tc.err.Error(), err.Error())
+			} else {
+				assert.NoError(t, err)
+			}
+			logger.AssertExpectations(t)
+			client.AssertExpectations(t)
+			fileManager.AssertExpectations(t)
+		})
+	}
+}