restore: carry a VNC password into the relaunch; drop the one-implementation Actions interfaces (#38)

* cut: drop the one-implementation Actions interfaces

cmd/vm and cmd/image each declared an Actions interface with a single
Handler behind it and a compile-time assertion to match; Command takes
the Handler.

* restore: carry a VNC password into the relaunch of a running VM

A running VM whose display is password-gated could only be restored by
stopping it first, since the password is never persisted. restore now
takes --vnc-password like start does and hands it to the relaunch; a
password-gated display without the flag is still refused before any
disk is touched. docs/snapshots.md states the rule and the window for
VMs launched before the password-set bit existed.

Author: CMGS

cmd/image/commands.go

@@ -6,16 +6,8 @@ import (
 	"github.com/cocoonstack/cocoon/cmd/cliutil"
 )
 
-// Actions is the image-subcommand surface, backed by cocoon's cloudimg store.
-type Actions interface {
-	Pull(cmd *cobra.Command, args []string) error
-	List(cmd *cobra.Command, args []string) error
-	Inspect(cmd *cobra.Command, args []string) error
-	RM(cmd *cobra.Command, args []string) error
-}
-
 // Command builds the `image` subcommand tree against the given handler.
-func Command(h Actions) *cobra.Command {
+func Command(h *Handler) *cobra.Command {
 	imageCmd := &cobra.Command{Use: "image", Short: "Manage macOS disk images (reuses cocoon's cloudimg store)"} // --state-dir is a root persistent flag
 
 	pull := &cobra.Command{

cmd/image/handler.go

@@ -16,9 +16,7 @@ import (
 
 const maxPullAttempts = 3
 
-var _ Actions = (*Handler)(nil)
-
-// Handler implements Actions on cocoon's cloudimg store.
+// Handler is the image command surface on cocoon's cloudimg store.
 type Handler struct{}
 
 // NewHandler returns a Handler backed by the cloudimg store.

cmd/vm/commands.go

@@ -6,23 +6,8 @@ import (
 	"github.com/cocoonstack/cocoon/cmd/cliutil"
 )
 
-// Actions mirrors cocoon's cmd/vm Actions, re-declared rather than imported because cocoon's commands.go drags in the Linux-only CH/netlink backend.
-type Actions interface {
-	Create(cmd *cobra.Command, args []string) error
-	Run(cmd *cobra.Command, args []string) error
-	Start(cmd *cobra.Command, args []string) error
-	Stop(cmd *cobra.Command, args []string) error
-	List(cmd *cobra.Command, args []string) error
-	Inspect(cmd *cobra.Command, args []string) error
-	Console(cmd *cobra.Command, args []string) error
-	RM(cmd *cobra.Command, args []string) error
-	Snapshot(cmd *cobra.Command, args []string) error
-	Restore(cmd *cobra.Command, args []string) error
-	Clone(cmd *cobra.Command, args []string) error
-}
-
 // Command builds the `vm` subcommand tree against the given handler.
-func Command(h Actions) *cobra.Command {
+func Command(h *Handler) *cobra.Command {
 	vmCmd := &cobra.Command{Use: "vm", Short: "Manage macOS VMs"} // --state-dir is a root persistent flag
 
 	createCmd := &cobra.Command{
@@ -104,6 +89,7 @@ func Command(h Actions) *cobra.Command {
 	}
 	restoreCmd.Flags().String("tag", "", "snapshot tag to restore (default: newest)")
 	restoreCmd.Flags().Bool("force", false, "stop the VM, restore, then relaunch if it was running")
+	restoreCmd.Flags().String("vnc-password", "", "VNC password for the relaunch of a running VM whose display is password-gated (≤8 chars)")
 
 	cloneCmd := &cobra.Command{
 		Use:   "clone SRC",

cmd/vm/handler.go

@@ -17,9 +17,7 @@ const (
 	netCNI    = "cni"
 )
 
-var _ Actions = (*Handler)(nil)
-
-// Handler implements the vm Actions: per-VM CoW overlays on a golden macOS qcow2, booted by qemu-system-x86_64 on an x86 Linux/KVM host.
+// Handler is the vm command surface: per-VM CoW overlays on a golden macOS qcow2, booted by qemu-system-x86_64 on an x86 Linux/KVM host.
 type Handler struct{}
 
 // NewHandler returns a Handler ready to serve the vm subcommands.

cmd/vm/lifecycle_test.go

@@ -65,6 +65,7 @@ func TestRestoreRefusesRunningPasswordedVNC(t *testing.T) {
 	cmd := newLifecycleTestCommand(t, stateDir)
 	cmd.Flags().String("tag", "", "")
 	cmd.Flags().Bool("force", true, "")
+	cmd.Flags().String("vnc-password", "", "")
 
 	err = NewHandler().Restore(cmd, []string{"macos-demo"})
 	if err == nil || !strings.Contains(err.Error(), "password-gated VNC") {

cmd/vm/snapshot.go

@@ -67,9 +67,14 @@ func (h *Handler) Restore(cmd *cobra.Command, args []string) error {
 			if force, _ := cmd.Flags().GetBool("force"); !force {
 				return fmt.Errorf("vm %q is running; stop it first or pass --force to stop+restore", r.Name)
 			}
-			if r.VNCDisp >= 0 && (r.VNCPassSet || r.Netns != "") {
-				return fmt.Errorf("vm %q serves a password-gated VNC display and a relaunch cannot carry the password; stop it, restore, then start --vnc %d --vnc-password", r.Name, r.VNCDisp)
+			vncPass, _ := cmd.Flags().GetString("vnc-password")
+			if err := validateVNCPassword(vncPass); err != nil {
+				return err
+			}
+			if vncPass == "" && r.VNCDisp >= 0 && (r.VNCPassSet || r.Netns != "") {
+				return fmt.Errorf("vm %q serves a password-gated VNC display; pass --vnc-password to relaunch it, or stop, restore, then start --vnc %d --vnc-password", r.Name, r.VNCDisp)
 			}
+			r.VNCPass = vncPass
 			terminate(ctx, r, stopGracePeriod)
 			r.PID = 0
 			if err := saveRec(dir, r); err != nil {

docs/snapshots.md

@@ -8,6 +8,14 @@ cocoon-macos vm snapshot m1 --tag clean
 cocoon-macos vm restore  m1 --tag clean   # --force to stop+restore+relaunch a running VM
 ```
 
+`--force` on a running VM keeps its VNC display across the relaunch. A display
+that was started with `--vnc-password` (every CNI display, optionally others)
+needs the password again: pass `--vnc-password` to `restore`, or stop, restore
+and `start --vnc N --vnc-password`; without it the restore is refused before
+any disk is touched. VMs launched by a cocoon-macos older than this rule with a
+passworded non-CNI display are not recognised as password-gated until their
+next stop or start.
+
 Snapshots are **offline qcow2-internal** (`qemu-img snapshot`, VM stopped) and capture **disk state
 only**. Live RAM snapshot is intentionally impossible here: `-cpu +invtsc` makes the macOS guest
 non-migratable, so resume-from-RAM can't work. This is by design (see [Roadmap](roadmap.md)).