Re-use username for UID if it exists

cmd/gluetun/main.go

@@ -118,7 +118,8 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 	// Should never change
 	uid, gid := allSettings.System.UID, allSettings.System.GID
 
-	err = alpineConf.CreateUser("nonrootuser", uid)
+	const defaultUsername = "nonrootuser"
+	nonRootUsername, err := alpineConf.CreateUser(defaultUsername, uid)
 	if err != nil {
 		logger.Error(err)
 		return 1
@@ -217,7 +218,7 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 
 	go collectStreamLines(ctx, streamMerger, logger, signalTunnelReady)
 
-	openvpnLooper := openvpn.NewLooper(allSettings.OpenVPN, uid, gid, allServers,
+	openvpnLooper := openvpn.NewLooper(allSettings.OpenVPN, nonRootUsername, uid, gid, allServers,
 		ovpnConf, firewallConf, routingConf, logger, httpClient, fileManager, streamMerger, cancel)
 	wg.Add(1)
 	// wait for restartOpenvpn
@@ -229,7 +230,7 @@ func _main(background context.Context, args []string) int { //nolint:gocognit,go
 	// wait for updaterLooper.Restart() or its ticket launched with RunRestartTicker
 	go updaterLooper.Run(ctx, wg)
 
-	unboundLooper := dns.NewLooper(dnsConf, allSettings.DNS, logger, streamMerger, uid, gid)
+	unboundLooper := dns.NewLooper(dnsConf, allSettings.DNS, logger, streamMerger, nonRootUsername, uid, gid)
 	wg.Add(1)
 	// wait for unboundLooper.Restart or its ticker launched with RunRestartTicker
 	go unboundLooper.Run(ctx, wg, signalDNSReady)

internal/alpine/alpine.go

@@ -7,7 +7,7 @@ import (
 )
 
 type Configurator interface {
-	CreateUser(username string, uid int) error
+	CreateUser(username string, uid int) (createdUsername string, err error)
 }
 
 type configurator struct {

internal/alpine/users.go

@@ -6,34 +6,34 @@ import (
 )
 
 // CreateUser creates a user in Alpine with the given UID.
-func (c *configurator) CreateUser(username string, uid int) error {
+func (c *configurator) CreateUser(username string, uid int) (createdUsername string, err error) {
 	UIDStr := fmt.Sprintf("%d", uid)
 	u, err := c.lookupUID(UIDStr)
 	_, unknownUID := err.(user.UnknownUserIdError)
 	if err != nil && !unknownUID {
-		return fmt.Errorf("cannot create user: %w", err)
+		return "", fmt.Errorf("cannot create user: %w", err)
 	} else if u != nil {
 		if u.Username == username {
-			return nil
+			return "", nil
 		}
-		return fmt.Errorf("user with ID %d exists with username %q instead of %q", uid, u.Username, username)
+		return u.Username, nil
 	}
 	u, err = c.lookupUser(username)
 	_, unknownUsername := err.(user.UnknownUserError)
 	if err != nil && !unknownUsername {
-		return fmt.Errorf("cannot create user: %w", err)
+		return "", fmt.Errorf("cannot create user: %w", err)
 	} else if u != nil {
-		return fmt.Errorf("cannot create user: user with name %s already exists for ID %s instead of %d",
+		return "", fmt.Errorf("cannot create user: user with name %s already exists for ID %s instead of %d",
 			username, u.Uid, uid)
 	}
 	passwd, err := c.fileManager.ReadFile("/etc/passwd")
 	if err != nil {
-		return fmt.Errorf("cannot create user: %w", err)
+		return "", fmt.Errorf("cannot create user: %w", err)
 	}
 	passwd = append(passwd, []byte(fmt.Sprintf("%s:x:%d:::/dev/null:/sbin/nologin\n", username, uid))...)
 
 	if err := c.fileManager.WriteToFile("/etc/passwd", passwd); err != nil {
-		return fmt.Errorf("cannot create user: %w", err)
+		return "", fmt.Errorf("cannot create user: %w", err)
 	}
-	return nil
+	return username, nil
 }

internal/cli/cli.go

@@ -71,8 +71,7 @@ func OpenvpnConfig() error {
 	lines := providerConf.BuildConf(
 		connection,
 		allSettings.OpenVPN.Verbosity,
-		allSettings.System.UID,
+		"nonroortuser",
-		allSettings.System.GID,
 		allSettings.OpenVPN.Root,
 		allSettings.OpenVPN.Cipher,
 		allSettings.OpenVPN.Auth,

internal/dns/conf.go

@@ -14,9 +14,10 @@ import (
 	"github.com/qdm12/golibs/network"
 )
 
-func (c *configurator) MakeUnboundConf(ctx context.Context, settings settings.DNS, uid, gid int) (err error) {
+func (c *configurator) MakeUnboundConf(ctx context.Context, settings settings.DNS,
+	username string, uid, gid int) (err error) {
 	c.logger.Info("generating Unbound configuration")
-	lines, warnings := generateUnboundConf(ctx, settings, c.client, c.logger)
+	lines, warnings := generateUnboundConf(ctx, settings, username, c.client, c.logger)
 	for _, warning := range warnings {
 		c.logger.Warn(warning)
 	}
@@ -28,7 +29,7 @@ func (c *configurator) MakeUnboundConf(ctx context.Context, settings settings.DN
 }
 
 // MakeUnboundConf generates an Unbound configuration from the user provided settings.
-func generateUnboundConf(ctx context.Context, settings settings.DNS,
+func generateUnboundConf(ctx context.Context, settings settings.DNS, username string,
 	client network.Client, logger logging.Logger) (
 	lines []string, warnings []error) {
 	doIPv6 := "no"
@@ -69,7 +70,7 @@ func generateUnboundConf(ctx context.Context, settings settings.DNS,
 		"interface": "0.0.0.0",
 		"port":      "53",
 		// Other
-		"username": "\"nonrootuser\"",
+		"username": fmt.Sprintf("%q", username),
 	}
 
 	// Block lists

internal/dns/conf_test.go

@@ -41,7 +41,7 @@ func Test_generateUnboundConf(t *testing.T) {
 	logger := mock_logging.NewMockLogger(mockCtrl)
 	logger.EXPECT().Info("%d hostnames blocked overall", 2).Times(1)
 	logger.EXPECT().Info("%d IP addresses blocked overall", 3).Times(1)
-	lines, warnings := generateUnboundConf(ctx, settings, client, logger)
+	lines, warnings := generateUnboundConf(ctx, settings, "nonrootuser", client, logger)
 	require.Len(t, warnings, 0)
 	expected := `
 server:

internal/dns/dns.go

@@ -15,7 +15,7 @@ import (
 type Configurator interface {
 	DownloadRootHints(ctx context.Context, uid, gid int) error
 	DownloadRootKey(ctx context.Context, uid, gid int) error
-	MakeUnboundConf(ctx context.Context, settings settings.DNS, uid, gid int) (err error)
+	MakeUnboundConf(ctx context.Context, settings settings.DNS, username string, uid, gid int) (err error)
 	UseDNSInternally(IP net.IP)
 	UseDNSSystemWide(ip net.IP, keepNameserver bool) error
 	Start(ctx context.Context, logLevel uint8) (stdout io.ReadCloser, waitFn func() error, err error)

internal/dns/loop.go

@@ -27,6 +27,7 @@ type looper struct {
 	conf         Configurator
 	logger       logging.Logger
 	streamMerger command.StreamMerger
+	username     string
 	uid          int
 	gid          int
 	loopLock     sync.Mutex
@@ -40,7 +41,7 @@ type looper struct {
 }
 
 func NewLooper(conf Configurator, settings settings.DNS, logger logging.Logger,
-	streamMerger command.StreamMerger, uid, gid int) Looper {
+	streamMerger command.StreamMerger, username string, uid, gid int) Looper {
 	return &looper{
 		state: state{
 			status:   constants.Stopped,
@@ -48,6 +49,7 @@ func NewLooper(conf Configurator, settings settings.DNS, logger logging.Logger,
 		},
 		conf:         conf,
 		logger:       logger.WithPrefix("dns over tls: "),
+		username:     username,
 		uid:          uid,
 		gid:          gid,
 		streamMerger: streamMerger,
@@ -292,7 +294,7 @@ func (l *looper) updateFiles(ctx context.Context) (err error) {
 		return err
 	}
 	settings := l.GetSettings()
-	if err := l.conf.MakeUnboundConf(ctx, settings, l.uid, l.gid); err != nil {
+	if err := l.conf.MakeUnboundConf(ctx, settings, l.username, l.uid, l.gid); err != nil {
 		return err
 	}
 	return nil

internal/openvpn/loop.go

@@ -33,8 +33,9 @@ type Looper interface {
 type looper struct {
 	state state
 	// Fixed parameters
-	uid int
+	username string
-	gid int
+	uid      int
+	gid      int
 	// Configurators
 	conf    Configurator
 	fw      firewall.Configurator
@@ -54,7 +55,7 @@ type looper struct {
 }
 
 func NewLooper(settings settings.OpenVPN,
-	uid, gid int, allServers models.AllServers,
+	username string, uid, gid int, allServers models.AllServers,
 	conf Configurator, fw firewall.Configurator, routing routing.Routing,
 	logger logging.Logger, client *http.Client, fileManager files.FileManager,
 	streamMerger command.StreamMerger, cancel context.CancelFunc) Looper {
@@ -64,6 +65,7 @@ func NewLooper(settings settings.OpenVPN,
 			settings:   settings,
 			allServers: allServers,
 		},
+		username:           username,
 		uid:                uid,
 		gid:                gid,
 		conf:               conf,
@@ -107,8 +109,7 @@ func (l *looper) Run(ctx context.Context, wg *sync.WaitGroup) {
 		lines := providerConf.BuildConf(
 			connection,
 			settings.Verbosity,
-			l.uid,
+			l.username,
-			l.gid,
 			settings.Root,
 			settings.Cipher,
 			settings.Auth,

internal/provider/cyberghost.go

@@ -62,8 +62,8 @@ func (c *cyberghost) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, c.randSource), nil
 }
 
-func (c *cyberghost) BuildConf(connection models.OpenVPNConnection, verbosity,
+func (c *cyberghost) BuildConf(connection models.OpenVPNConnection, verbosity int,
-	uid, gid int, root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
+	username string, root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
 	}
@@ -105,7 +105,7 @@ func (c *cyberghost) BuildConf(connection models.OpenVPNConnection, verbosity,
 		lines = append(lines, "ncp-ciphers AES-256-GCM:AES-256-CBC:AES-128-GCM")
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/mullvad.go

@@ -73,7 +73,7 @@ func (m *mullvad) GetOpenVPNConnection(selection models.ServerSelection) (
 }
 
 func (m *mullvad) BuildConf(connection models.OpenVPNConnection,
-	verbosity, uid, gid int, root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
+	verbosity int, username string, root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
 	}
@@ -114,7 +114,7 @@ func (m *mullvad) BuildConf(connection models.OpenVPNConnection,
 		lines = append(lines, `pull-filter ignore "ifconfig-ipv6"`)
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/nordvpn.go

@@ -78,7 +78,7 @@ func (n *nordvpn) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, n.randSource), nil
 }
 
-func (n *nordvpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int, root bool,
+func (n *nordvpn) BuildConf(connection models.OpenVPNConnection, verbosity int, username string, root bool,
 	cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -121,7 +121,7 @@ func (n *nordvpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid,
 		fmt.Sprintf("auth %s", auth),
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/piav4.go

@@ -109,7 +109,7 @@ func (p *pia) GetOpenVPNConnection(selection models.ServerSelection) (
 	return connection, nil
 }
 
-func (p *pia) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int, root bool,
+func (p *pia) BuildConf(connection models.OpenVPNConnection, verbosity int, username string, root bool,
 	cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	var X509CRL, certificate string
 	var defaultCipher, defaultAuth string
@@ -161,7 +161,7 @@ func (p *pia) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid
 		lines = append(lines, "ncp-disable")
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<crl-verify>",

internal/provider/privado.go

@@ -70,7 +70,7 @@ func (s *privado) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, s.randSource), nil
 }
 
-func (s *privado) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int, root bool,
+func (s *privado) BuildConf(connection models.OpenVPNConnection, verbosity int, username string, root bool,
 	cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -104,7 +104,7 @@ func (s *privado) BuildConf(connection models.OpenVPNConnection, verbosity, uid,
 		fmt.Sprintf("auth %s", auth),
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/provider.go

@@ -15,7 +15,7 @@ import (
 // Provider contains methods to read and modify the openvpn configuration to connect as a client.
 type Provider interface {
 	GetOpenVPNConnection(selection models.ServerSelection) (connection models.OpenVPNConnection, err error)
-	BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int,
+	BuildConf(connection models.OpenVPNConnection, verbosity int, username string,
 		root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string)
 	PortForward(ctx context.Context, client *http.Client,
 		fileManager files.FileManager, pfLogger logging.Logger, gateway net.IP, fw firewall.Configurator,

internal/provider/purevpn.go

@@ -72,7 +72,7 @@ func (p *purevpn) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, p.randSource), nil
 }
 
-func (p *purevpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int, root bool,
+func (p *purevpn) BuildConf(connection models.OpenVPNConnection, verbosity int, username string, root bool,
 	cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -108,7 +108,7 @@ func (p *purevpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid,
 		fmt.Sprintf("cipher %s", cipher),
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/surfshark.go

@@ -73,7 +73,7 @@ func (s *surfshark) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, s.randSource), nil
 }
 
-func (s *surfshark) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int, root bool,
+func (s *surfshark) BuildConf(connection models.OpenVPNConnection, verbosity int, username string, root bool,
 	cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -117,7 +117,7 @@ func (s *surfshark) BuildConf(connection models.OpenVPNConnection, verbosity, ui
 		fmt.Sprintf("auth %s", auth),
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/vyprvpn.go

@@ -69,7 +69,7 @@ func (v *vyprvpn) GetOpenVPNConnection(selection models.ServerSelection) (
 	return pickRandomConnection(connections, v.randSource), nil
 }
 
-func (v *vyprvpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int,
+func (v *vyprvpn) BuildConf(connection models.OpenVPNConnection, verbosity int, username string,
 	root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -106,7 +106,7 @@ func (v *vyprvpn) BuildConf(connection models.OpenVPNConnection, verbosity, uid,
 		fmt.Sprintf("auth %s", auth),
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",

internal/provider/windscribe.go

@@ -72,7 +72,7 @@ func (w *windscribe) GetOpenVPNConnection(selection models.ServerSelection) (con
 	return pickRandomConnection(connections, w.randSource), nil
 }
 
-func (w *windscribe) BuildConf(connection models.OpenVPNConnection, verbosity, uid, gid int,
+func (w *windscribe) BuildConf(connection models.OpenVPNConnection, verbosity int, username string,
 	root bool, cipher, auth string, extras models.ExtraConfigOptions) (lines []string) {
 	if len(cipher) == 0 {
 		cipher = aes256cbc
@@ -111,7 +111,7 @@ func (w *windscribe) BuildConf(connection models.OpenVPNConnection, verbosity, u
 		lines = append(lines, "ncp-ciphers AES-256-GCM:AES-256-CBC:AES-128-GCM")
 	}
 	if !root {
-		lines = append(lines, "user nonrootuser")
+		lines = append(lines, "user "+username)
 	}
 	lines = append(lines, []string{
 		"<ca>",