Allow the user to share multiple Host folders in the Guest via virtio9p

Previously, only "/Users" was being shared inside the guest at "/Users".

With this commit, it is possible to mount any Host folder inside the Guest at "/xhyve-virtio9p". This default can be changed via the `--xhyve-virtio-9p-root` command line argument.

This commit changes `--xhyve-virtio-9p` from a bool flag to a string slice representing the absolute path to the Host folder to be mounted inside the guest.

There is currently, however, a major caveat, that is that using Virtio9p shares and NFS Shares at the same time will not work. After restarting the machine, the NFS mounts will disappear from the Guest. This issue will be addressed in the next commit.

Author: huguesalary

xhyve/xhyve.go

@@ -56,7 +56,7 @@ const (
 	defaultNFSSharesRoot  = "/xhyve-nfsshares"
 	rootVolumeName        = "root-volume"
 	defaultDiskNumber     = -1
-	defaultVirtio9p       = false
+	defaultVirtio9pRoot   = "/xhyve-virtio9p"
 	defaultQcow2          = false
 	defaultRawDisk        = false
 )
@@ -69,19 +69,19 @@ type Driver struct {
 	CaCertPath     string
 	PrivateKeyPath string
 
-	CPU            int
-	Memory         int
-	DiskSize       int64
-	DiskNumber     int
-	MacAddr        string
-	UUID           string
-	Qcow2          bool
-	RawDisk        bool
-	NFSShares      []string
-	NFSSharesRoot  string
-	Virtio9p       bool
-	Virtio9pFolder string
-	NFSShare       bool
+	CPU           int
+	Memory        int
+	DiskSize      int64
+	DiskNumber    int
+	MacAddr       string
+	UUID          string
+	Qcow2         bool
+	RawDisk       bool
+	NFSShares     []string
+	NFSSharesRoot string
+	Virtio9p      []string
+	Virtio9pRoot  string
+	NFSShare      bool
 
 	BootCmd    string
 	BootKernel string
@@ -116,9 +116,9 @@ func NewDriver(hostName, storePath string) *Driver {
 		Memory:         defaultMemory,
 		PrivateKeyPath: defaultPrivateKeyPath,
 		UUID:           defaultUUID,
+		Virtio9pRoot:   defaultVirtio9pRoot,
 		NFSSharesRoot:  defaultNFSSharesRoot,
 		DiskNumber:     defaultDiskNumber,
-		Virtio9p:       defaultVirtio9p,
 		Qcow2:          defaultQcow2,
 		RawDisk:        defaultRawDisk,
 	}
@@ -186,10 +186,16 @@ func (d *Driver) GetCreateFlags() []mcnflag.Flag {
 			Usage:  "The UUID for the machine",
 			Value:  defaultUUID,
 		},
-		mcnflag.BoolFlag{
+		mcnflag.StringSliceFlag{
 			EnvVar: "XHYVE_VIRTIO_9P",
 			Name:   "xhyve-virtio-9p",
-			Usage:  "Setup virtio-9p folder share",
+			Usage:  "Setup virtio-9p folder share(s)",
+		},
+		mcnflag.StringFlag{
+			EnvVar: "XHYVE_VIRTIO_9P_ROOT",
+			Name:   "xhyve-virtio-9p-root",
+			Usage:  "root directory where the virtio shared folder will be mounted inside the machine",
+			Value:  defaultVirtio9pRoot,
 		},
 		mcnflag.StringSliceFlag{
 			EnvVar: "XHYVE_EXPERIMENTAL_NFS_SHARE",
@@ -256,8 +262,8 @@ func (d *Driver) SetConfigFromFlags(flags drivers.DriverOptions) error {
 	d.SwarmHost = flags.String("swarm-host")
 	d.SwarmMaster = flags.Bool("swarm-master")
 	d.UUID = flags.String("xhyve-uuid")
-	d.Virtio9p = flags.Bool("xhyve-virtio-9p")
-	d.Virtio9pFolder = "/Users"
+	d.Virtio9p = flags.StringSlice("xhyve-virtio-9p")
+	d.Virtio9pRoot = flags.String("xhyve-virtio-9p-root")
 	d.NFSShares = flags.StringSlice("xhyve-experimental-nfs-share")
 	d.NFSSharesRoot = flags.String("xhyve-experimental-nfs-share-root")
 
@@ -497,8 +503,14 @@ func (d *Driver) Start() error {
 
 	args := d.xhyveArgs()
 	args = append(args, "-F", fmt.Sprintf("%s", pid))
-	if d.Virtio9p {
-		args = append(args, "-s", fmt.Sprintf("5,virtio-9p,host=%s", d.Virtio9pFolder))
+	if len(d.Virtio9p) > 0 {
+		const virtio9pPciStartValue = 5
+		i := virtio9pPciStartValue
+		for _, virtioshare := range d.Virtio9p {
+			// In the following line, i-virtio9pPciStartValue is just so that the string "host-" starts from 0 and not from 5
+			args = append(args, "-s", fmt.Sprintf("%d,virtio-9p,host-%d=%s", i, i-virtio9pPciStartValue, virtioshare))
+			i++
+		}
 	}
 
 	log.Debug(args)
@@ -814,7 +826,7 @@ func (d *Driver) generateQcow2Image(size int64) error {
 }
 
 func (d *Driver) setupMounts() error {
-	if d.Virtio9p {
+	if len(d.Virtio9p) > 0 {
 		err := d.setupVirt9pShare()
 		if err != nil {
 			log.Errorf("virtio-9p setup failed: %s", err.Error())
@@ -983,9 +995,16 @@ func (d *Driver) setupVirt9pShare() error {
 		return err
 	}
 	bootScriptName := "/var/lib/boot2docker/bootlocal.sh"
-	bootScript := fmt.Sprintf("#/bin/bash\\n"+
-		"sudo mkdir -p %s\\n"+
-		"sudo mount -t 9p -o version=9p2000 -o trans=virtio -o uname=%s -o dfltuid=$(id -u docker) -o dfltgid=50 -o access=any host %s", d.Virtio9pFolder, user.Username, d.Virtio9pFolder)
+
+	bootScript := fmt.Sprintf("#/bin/bash\\n")
+	i := 0
+	for _, virtioShare := range d.Virtio9p {
+		bootScript = fmt.Sprintf("%s\\n", bootScript)
+		fullMountPath := path.Clean(d.Virtio9pRoot + "/" + virtioShare)
+		bootScript += fmt.Sprintf("sudo mkdir -p %s\\n", fullMountPath)
+		bootScript += fmt.Sprintf("sudo mount -t 9p -o version=9p2000 -o trans=virtio -o uname=%s -o dfltuid=$(id -u docker) -o dfltgid=50 -o access=any host-%d %s", user.Username, i, fullMountPath)
+		i++
+	}
 
 	writeScriptCmd := fmt.Sprintf("echo -e \"%s\" | sudo tee %s && sudo chmod +x %s && %s",
 		bootScript, bootScriptName, bootScriptName, bootScriptName)