Implement virtfs volumes for podman machine

Allow using the built-in 9pfs feature of qemu,
mounting host directories into vm mountpoints.

The volumes are generic, the mounts are specific.

Wait for the machine to be "running", otherwise
the SSH function might throw an error instead.

Increase the default msize from 8 KiB to 128 KiB

[NO NEW TESTS NEEDED]

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

2 files changed, 56 insertions, 1 deletions

diff --git a/pkg/machine/qemu/config.go b/pkg/machine/qemu/config.go
index 8404079a2..177487953 100644
--- a/pkg/machine/qemu/config.go
+++ b/pkg/machine/qemu/config.go
@@ -11,6 +11,8 @@ type MachineVM struct {
 	CPUs uint64
 	// The command line representation of the qemu command
 	CmdLine []string
+	// Mounts is the list of remote filesystems to mount
+	Mounts []Mount
 	// IdentityPath is the fq path to the ssh priv key
 	IdentityPath string
 	// IgnitionFilePath is the fq path to the .ign file
@@ -33,6 +35,13 @@ type MachineVM struct {
 	RemoteUsername string
 }
 
+type Mount struct {
+	Type   string
+	Tag    string
+	Source string
+	Target string
+}
+
 type Monitor struct {
 	//	Address portion of the qmp monitor (/tmp/tmp.sock)
 	Address string
diff --git a/pkg/machine/qemu/machine.go b/pkg/machine/qemu/machine.go
index a80a11573..7bef4ff8e 100644
--- a/pkg/machine/qemu/machine.go
+++ b/pkg/machine/qemu/machine.go
@@ -167,6 +167,21 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 	// Add arch specific options including image location
 	v.CmdLine = append(v.CmdLine, v.addArchOptions()...)
 
+	mounts := []Mount{}
+	for i, volume := range opts.Volumes {
+		tag := fmt.Sprintf("vol%d", i)
+		paths := strings.SplitN(volume, ":", 2)
+		source := paths[0]
+		target := source
+		if len(paths) > 1 {
+			target = paths[1]
+		}
+		addVirtfsOptions := []string{"-virtfs", fmt.Sprintf("local,path=%s,mount_tag=%s,security_model=mapped-xattr", source, tag)}
+		v.CmdLine = append(v.CmdLine, addVirtfsOptions...)
+		mounts = append(mounts, Mount{Type: "9p", Tag: tag, Source: source, Target: target})
+	}
+	v.Mounts = mounts
+
 	// Add location of bootable image
 	v.CmdLine = append(v.CmdLine, "-drive", "if=virtio,file="+v.ImagePath)
 	// This kind of stinks but no other way around this r/n
@@ -329,7 +344,28 @@ func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 		return err
 	}
 	_, err = bufio.NewReader(conn).ReadString('\n')
-	return err
+	if err != nil {
+		return err
+	}
+
+	if len(v.Mounts) > 0 {
+		for !v.isRunning() || !v.isListening() {
+			time.Sleep(100 * time.Millisecond)
+		}
+	}
+	for _, mount := range v.Mounts {
+		fmt.Printf("Mounting volume... %s:%s\n", mount.Source, mount.Target)
+		// create mountpoint directory if it doesn't exist
+		err = v.SSH(name, machine.SSHOptions{Args: []string{"-q", "--", "sudo", "mkdir", "-p", mount.Target}})
+		if err != nil {
+			return err
+		}
+		err = v.SSH(name, machine.SSHOptions{Args: []string{"-q", "--", "sudo", "mount", "-t", mount.Type, "-o", "trans=virtio", mount.Tag, mount.Target, "-o", "version=9p2000.L,msize=131072"}})
+		if err != nil {
+			return err
+		}
+	}
+	return nil
 }
 
 // Stop uses the qmp monitor to call a system_powerdown
@@ -506,6 +542,16 @@ func (v *MachineVM) isRunning() bool {
 	return true
 }
 
+func (v *MachineVM) isListening() bool {
+	// Check if we can dial it
+	conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%d", "localhost", v.Port), 10*time.Millisecond)
+	if err != nil {
+		return false
+	}
+	conn.Close()
+	return true
+}
+
 // SSH opens an interactive SSH session to the vm specified.
 // Added ssh function to VM interface: pkg/machine/config/go : line 58
 func (v *MachineVM) SSH(name string, opts machine.SSHOptions) error {