Add configurable port for minikube mount

cmd/minikube/cmd/mount.go

@@ -50,6 +50,7 @@ const (
 // placeholders for flag values
 var (
 	mountIP      string
+	mountPort    uint16
 	mountVersion string
 	mountType    string
 	isKill       bool
@@ -191,6 +192,9 @@ var mountCmd = &cobra.Command{
 
 		err = cluster.Mount(co.CP.Runner, ip.String(), vmPath, cfg)
 		if err != nil {
+			if rtErr, ok := err.(*cluster.MountError); ok && rtErr.ErrorType == cluster.MountErrorConnect {
+				exit.Error(reason.GuestMountCouldNotConnect, "mount could not connect", rtErr)
+			}
 			exit.Error(reason.GuestMount, "mount failed", err)
 		}
 		out.Step(style.Success, "Successfully mounted {{.sourcePath}} to {{.destinationPath}}", out.V{"sourcePath": hostPath, "destinationPath": vmPath})
@@ -202,6 +206,7 @@ var mountCmd = &cobra.Command{
 
 func init() {
 	mountCmd.Flags().StringVar(&mountIP, "ip", "", "Specify the ip that the mount should be setup on")
+	mountCmd.Flags().Uint16Var(&mountPort, "port", 0, "Specify the port that the mount should be setup on, where 0 means any free port.")
 	mountCmd.Flags().StringVar(&mountType, "type", nineP, "Specify the mount filesystem type (supported types: 9p)")
 	mountCmd.Flags().StringVar(&mountVersion, "9p-version", defaultMountVersion, "Specify the 9p version that the mount should use")
 	mountCmd.Flags().BoolVar(&isKill, "kill", false, "Kill the mount process spawned by minikube start")
@@ -212,9 +217,9 @@ func init() {
 	mountCmd.Flags().IntVar(&mSize, "msize", defaultMsize, "The number of bytes to use for 9p packet payload")
 }
 
-// getPort asks the kernel for a free open port that is ready to use
+// getPort uses the requested port or asks the kernel for a free open port that is ready to use
 func getPort() (int, error) {
-	addr, err := net.ResolveTCPAddr("tcp", "localhost:0")
+	addr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf("localhost:%d", mountPort))
 	if err != nil {
 		panic(err)
 	}

pkg/minikube/cluster/mount.go

@@ -54,19 +54,41 @@ type mountRunner interface {
 	RunCmd(*exec.Cmd) (*command.RunResult, error)
 }
 
+const (
+	// MountErrorUnknown failed with unknown error
+	MountErrorUnknown = iota
+	// MountErrorConnect
+	MountErrorConnect
+)
+
+// MountError wrapper around errors in the `Mount` function
+type MountError struct {
+	// ErrorType enum for more info about the error
+	ErrorType int
+	// UnderlyingError the error being wrapped
+	UnderlyingError error
+}
+
+func (m *MountError) Error() string {
+	return m.UnderlyingError.Error()
+}
+
 // Mount runs the mount command from the 9p client on the VM to the 9p server on the host
 func Mount(r mountRunner, source string, target string, c *MountConfig) error {
 	if err := Unmount(r, target); err != nil {
-		return errors.Wrap(err, "umount")
+		return &MountError{ErrorType: MountErrorUnknown, UnderlyingError: errors.Wrap(err, "umount")}
 	}
 
 	if _, err := r.RunCmd(exec.Command("/bin/bash", "-c", fmt.Sprintf("sudo mkdir -m %o -p %s", c.Mode, target))); err != nil {
-		return errors.Wrap(err, "create folder pre-mount")
+		return &MountError{ErrorType: MountErrorUnknown, UnderlyingError: errors.Wrap(err, "create folder pre-mount")}
 	}
 
 	rr, err := r.RunCmd(exec.Command("/bin/bash", "-c", mntCmd(source, target, c)))
 	if err != nil {
-		return errors.Wrapf(err, "mount with cmd %s ", rr.Command())
+		if strings.Contains(rr.Stderr.String(), "Connection timed out") {
+			return &MountError{ErrorType: MountErrorConnect, UnderlyingError: err}
+		}
+		return &MountError{ErrorType: MountErrorUnknown, UnderlyingError: errors.Wrapf(err, "mount with cmd %s ", rr.Command())}
 	}
 
 	klog.Infof("mount successful: %q", rr.Output())

pkg/minikube/reason/reason.go

@@ -321,6 +321,15 @@ var (
 	GuestLoadHost = Kind{ID: "GUEST_LOAD_HOST", ExitCode: ExGuestError}
 	// minkube failed to create a mount
 	GuestMount = Kind{ID: "GUEST_MOUNT", ExitCode: ExGuestError}
+	// mount on guest was unable to connect to host mount server
+	GuestMountCouldNotConnect = Kind{
+		ID:       "GUEST_MOUNT_COULD_NOT_CONNECT",
+		ExitCode: ExGuestError,
+		Advice: `If the host has a firewall:
+
+		1. Allow a port through the firewall
+		2. Specify "--port=<port_number>" for "minikube mount"`,
+	}
 	// minkube failed to update a mount
 	GuestMountConflict = Kind{ID: "GUEST_MOUNT_CONFLICT", ExitCode: ExGuestConflict}
 	// minikube failed to add a node to the cluster