Fixes #79 Create TUN device if it does not exist

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,
 	}
 }