Fixes #79 Create TUN device if it does not exist

cmd/main.go

@@ -57,8 +57,11 @@ func main() {
 	e.FatalOnError(err)
 	logger.Info(allSettings.String())
 
-	err = ovpnConf.CheckTUN()
+	if err := ovpnConf.CheckTUN(); err != nil {
-	e.FatalOnError(err)
+		logger.Warn(err)
+		err = ovpnConf.CreateTUN()
+		e.FatalOnError(err)
+	}
 
 	err = ovpnConf.WriteAuthFile(allSettings.PIA.User, allSettings.PIA.Password, uid, gid)
 	e.FatalOnError(err)

internal/openvpn/openvpn.go

@@ -7,6 +7,7 @@ import (
 	"github.com/qdm12/golibs/command"
 	"github.com/qdm12/golibs/files"
 	"github.com/qdm12/golibs/logging"
+	"golang.org/x/sys/unix"
 )
 
 const logPrefix = "openvpn configurator"
@@ -15,6 +16,7 @@ type Configurator interface {
 	Version() (string, error)
 	WriteAuthFile(user, password string, uid, gid int) error
 	CheckTUN() error
+	CreateTUN() error
 	Start() (stdout io.ReadCloser, err error)
 }
 
@@ -23,6 +25,8 @@ type configurator struct {
 	logger      logging.Logger
 	commander   command.Commander
 	openFile    func(name string, flag int, perm os.FileMode) (*os.File, error)
+	mkDev       func(major uint32, minor uint32) uint64
+	mkNod       func(path string, mode uint32, dev int) error
 }
 
 func NewConfigurator(logger logging.Logger, fileManager files.FileManager) Configurator {
@@ -31,5 +35,7 @@ func NewConfigurator(logger logging.Logger, fileManager files.FileManager) Confi
 		logger:      logger,
 		commander:   command.NewCommander(),
 		openFile:    os.OpenFile,
+		mkDev:       unix.Mkdev,
+		mkNod:       unix.Mknod,
 	}
 }

internal/openvpn/tun.go

@@ -5,6 +5,7 @@ import (
 	"os"
 
 	"github.com/qdm12/private-internet-access-docker/internal/constants"
+	"golang.org/x/sys/unix"
 )
 
 // CheckTUN checks the tunnel device is present and accessible
@@ -19,3 +20,18 @@ func (c *configurator) CheckTUN() error {
 	}
 	return nil
 }
+
+func (c *configurator) CreateTUN() error {
+	c.logger.Info("%s: creating %s", logPrefix, constants.TunnelDevice)
+	if err := c.fileManager.CreateDir("/dev/net"); err != nil {
+		return err
+	}
+	dev := c.mkDev(10, 200)
+	if err := c.mkNod(string(constants.TunnelDevice), unix.S_IFCHR, int(dev)); err != nil {
+		return err
+	}
+	if err := c.fileManager.SetUserPermissions(string(constants.TunnelDevice), 666); err != nil {
+		return err
+	}
+	return nil
+}