Feature: OPENVPN_VERSION which can be 2.4 or 2.5

internal/configuration/openvpn.go

@@ -21,7 +21,7 @@ type OpenVPN struct {
 	Auth      string   `json:"auth"`
 	Provider  Provider `json:"provider"`
 	Config    string   `json:"custom_config"`
-	Version   string   `json:"-"` // injected at runtime
+	Version   string   `json:"version"`
 }
 
 func (settings *OpenVPN) String() string {
@@ -31,6 +31,8 @@ func (settings *OpenVPN) String() string {
 func (settings *OpenVPN) lines() (lines []string) {
 	lines = append(lines, lastIndent+"OpenVPN:")
 
+	lines = append(lines, indent+lastIndent+"Version: "+settings.Version)
+
 	lines = append(lines, indent+lastIndent+"Verbosity level: "+strconv.Itoa(settings.Verbosity))
 
 	if settings.Root {
@@ -98,6 +100,12 @@ func (settings *OpenVPN) read(r reader) (err error) {
 		}
 	}
 
+	settings.Version, err = r.env.Inside("OPENVPN_VERSION",
+		[]string{constants.Openvpn24, constants.Openvpn25}, params.Default(constants.Openvpn25))
+	if err != nil {
+		return err
+	}
+
 	settings.Verbosity, err = r.env.IntRange("OPENVPN_VERBOSITY", 0, 6, params.Default("1"))
 	if err != nil {
 		return err

internal/configuration/openvpn_test.go

@@ -52,7 +52,8 @@ func Test_OpenVPN_JSON(t *testing.T) {
       "filepath": ""
     }
   },
-  "custom_config": ""
+  "custom_config": "",
+  "version": ""
 }`, string(data))
 	var out OpenVPN
 	err = json.Unmarshal(data, &out)

internal/configuration/settings_test.go

@@ -17,6 +17,7 @@ func Test_Settings_lines(t *testing.T) {
 		"default settings": {
 			settings: Settings{
 				OpenVPN: OpenVPN{
+					Version: constants.Openvpn25,
 					Provider: Provider{
 						Name: constants.Mullvad,
 					},
@@ -25,6 +26,7 @@ func Test_Settings_lines(t *testing.T) {
 			lines: []string{
 				"Settings summary below:",
 				"|--OpenVPN:",
+				"   |--Version: 2.5",
 				"   |--Verbosity level: 0",
 				"   |--Provider:",
 				"      |--Mullvad settings:",

internal/constants/openvpn.go

@@ -14,3 +14,8 @@ const (
 	SHA256    = "sha256"
 	SHA512    = "sha512"
 )
+
+const (
+	Openvpn24 = "2.4"
+	Openvpn25 = "2.5"
+)

internal/openvpn/command.go

@@ -9,16 +9,42 @@ import (
 	"github.com/qdm12/gluetun/internal/constants"
 )
 
-func (c *configurator) Start(ctx context.Context) (
+var ErrVersionUnknown = errors.New("OpenVPN version is unknown")
+
+const (
+	binOpenvpn24 = "openvpn2.4"
+	binOpenvpn25 = "openvpn"
+)
+
+func (c *configurator) Start(ctx context.Context, version string) (
 	stdoutLines, stderrLines chan string, waitError chan error, err error) {
-	c.logger.Info("starting openvpn")
-	return c.commander.Start(ctx, "openvpn", "--config", constants.OpenVPNConf)
+	var bin string
+	switch version {
+	case constants.Openvpn24:
+		bin = binOpenvpn24
+	case constants.Openvpn25:
+		bin = binOpenvpn25
+	default:
+		return nil, nil, nil, fmt.Errorf("%w: %s", ErrVersionUnknown, version)
+	}
+
+	c.logger.Info("starting OpenVPN " + version)
+
+	return c.commander.Start(ctx, bin, "--config", constants.OpenVPNConf)
+}
+
+func (c *configurator) Version24(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn24)
+}
+
+func (c *configurator) Version25(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn25)
 }
 
 var ErrVersionTooShort = errors.New("version output is too short")
 
-func (c *configurator) Version(ctx context.Context) (string, error) {
-	output, err := c.commander.Run(ctx, "openvpn", "--version")
+func (c *configurator) version(ctx context.Context, binName string) (version string, err error) {
+	output, err := c.commander.Run(ctx, binName, "--version")
 	if err != nil && err.Error() != "exit status 1" {
 		return "", err
 	}

internal/openvpn/loop.go

@@ -157,7 +157,7 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) { //nolint:gocog
 
 		openvpnCtx, openvpnCancel := context.WithCancel(context.Background())
 
-		stdoutLines, stderrLines, waitError, err := l.conf.Start(openvpnCtx)
+		stdoutLines, stderrLines, waitError, err := l.conf.Start(openvpnCtx, settings.Version)
 		if err != nil {
 			openvpnCancel()
 			l.signalCrashedStatus()

internal/openvpn/openvpn.go

@@ -12,12 +12,13 @@ import (
 )
 
 type Configurator interface {
-	Version(ctx context.Context) (string, error)
+	Version24(ctx context.Context) (version string, err error)
+	Version25(ctx context.Context) (version string, err error)
 	WriteAuthFile(user, password string, puid, pgid int) error
 	CheckTUN() error
 	CreateTUN() error
-	Start(ctx context.Context) (stdoutLines, stderrLines chan string,
-		waitError chan error, err error)
+	Start(ctx context.Context, version string) (
+		stdoutLines, stderrLines chan string, waitError chan error, err error)
 }
 
 type configurator struct {

internal/provider/utils/cipher.go

@@ -1,10 +1,12 @@
 package utils
 
-import "strings"
+import (
+	"github.com/qdm12/gluetun/internal/constants"
+)
 
 func CipherLines(cipher, version string) (lines []string) {
-	switch {
-	case strings.HasPrefix(version, "2.4"):
+	switch version {
+	case constants.Openvpn24:
 		return []string{"cipher " + cipher}
 	default: // 2.5 and above
 		return []string{

internal/provider/utils/cipher_test.go

@@ -18,12 +18,12 @@ func Test_CipherLines(t *testing.T) {
 				"data-ciphers AES",
 			},
 		},
-		"2.4.5": {
-			version: "2.4.5",
+		"2.4": {
+			version: "2.4",
 			lines:   []string{"cipher AES"},
 		},
-		"2.5.3": {
-			version: "2.5.3",
+		"2.5": {
+			version: "2.5",
 			lines: []string{
 				"data-ciphers-fallback AES",
 				"data-ciphers AES",