feat: show golden VM tag in clone list, add console logging, fix ubuntu boot

- Persist golden VM tag to clones/{id}/tag at spawn time
- GET /clones now returns [{id, tag}] objects instead of plain IDs
- Web UI renders tag as a dim label next to each clone entry (clone 3 · default)
- Pre-existing fixes included in this commit:
  - console: tee all PTY output to clones/{id}/console.log for boot capture
  - network: destroy stale tap before recreating to avoid EBUSY errors
  - orchestrator: fix ubuntu systemd boot (custom fc-console.service, fstab,
    mask serial-getty udev dep, longer settle time, correct package list)
  - config: remove quiet/loglevel=0 from default boot args

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

orchestrator/config.go

@@ -34,7 +34,7 @@ func DefaultConfig() Config {
 		GuestPrefix:  envOr("FC_GUEST_PREFIX", "172.30.0"),
 		GuestGW:      envOr("FC_GUEST_GW", "172.30.0.1"),
 		AutoNetConfig: envOr("FC_AUTO_NET_CONFIG", "") == "1",
-		BootArgs:     "console=ttyS0 reboot=k panic=1 pci=off i8042.noaux quiet loglevel=0",
+		BootArgs:     "console=ttyS0 reboot=k panic=1 pci=off i8042.noaux",
 	}
 	c.Kernel = envOr("FC_KERNEL", c.BaseDir+"/vmlinux")
 	c.KernelURL = envOr("FC_KERNEL_URL",

orchestrator/console.go

@@ -164,6 +164,17 @@ func RunConsoleProxy(cfg Config, id int, tapName, tag string) error {
 	logger.Infof("clone %d: restored in %s (pid=%d, tap=%s)",
 		id, elapsed.Round(time.Millisecond), cmd.Process.Pid, tapName)
 
+	// --- Open console log (captures all serial output from boot) ---
+	consoleLogPath := filepath.Join(cloneDir, "console.log")
+	consoleLog, err := os.OpenFile(consoleLogPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o644)
+	if err != nil {
+		logger.Warnf("could not open console log: %v", err)
+		consoleLog = nil
+	}
+	if consoleLog != nil {
+		defer consoleLog.Close()
+	}
+
 	// --- Create console socket ---
 	os.Remove(consoleSockPath) //nolint:errcheck
 	listener, err := net.Listen("unix", consoleSockPath)
@@ -191,7 +202,7 @@ func RunConsoleProxy(cfg Config, id int, tapName, tag string) error {
 	if resizeListener != nil {
 		go serveResize(resizeListener, ptm, vmDone, logger)
 	}
-	serveConsole(listener, ptm, vmDone, logger)
+	serveConsole(listener, ptm, consoleLog, vmDone, logger)
 
 	listener.Close()
 	if resizeListener != nil {
@@ -274,16 +285,20 @@ func (a *atomicWriter) Write(p []byte) (int, error) {
 // A background goroutine reads from the PTY master continuously (discarding
 // output when no client is connected so the VM never blocks on a full buffer).
 // Only one client is served at a time; sessions are serialised.
-func serveConsole(listener net.Listener, ptm *os.File, vmDone <-chan struct{}, logger *log.Entry) {
+func serveConsole(listener net.Listener, ptm *os.File, logFile *os.File, vmDone <-chan struct{}, logger *log.Entry) {
 	aw := &atomicWriter{w: io.Discard}
 
 	// Background PTY reader — runs for the full VM lifetime.
+	// All output is tee'd to logFile (if set) so boot messages are never lost.
 	go func() {
 		buf := make([]byte, 4096)
 		for {
 			n, err := ptm.Read(buf)
 			if n > 0 {
 				aw.Write(buf[:n]) //nolint:errcheck
+				if logFile != nil {
+					logFile.Write(buf[:n]) //nolint:errcheck
+				}
 			}
 			if err != nil {
 				return // PTY closed (VM exited)

orchestrator/network.go

@@ -54,6 +54,8 @@ func (o *Orchestrator) setupBridge() error {
 
 // createTap creates a tap device and attaches it to the bridge.
 func (o *Orchestrator) createTap(name string) error {
+	// Destroy any stale tap with this name before (re)creating it.
+	_ = run("ip", "link", "del", name)
 	if err := run("ip", "tuntap", "add", "dev", name, "mode", "tap"); err != nil {
 		return fmt.Errorf("create tap %s: %w", name, err)
 	}

orchestrator/orchestrator.go

@@ -80,7 +80,7 @@ func (o *Orchestrator) Init(distro string) error {
 
 func (o *Orchestrator) buildRootfs(distro, rootfsPath string) error {
 	sizeMB := 512
-	if distro == "debian" {
+	if distro == "debian" || distro == "ubuntu" {
 		sizeMB = 2048
 	}
 	mnt := filepath.Join(o.cfg.BaseDir, "mnt")
@@ -161,6 +161,8 @@ func (o *Orchestrator) buildRootfs(distro, rootfsPath string) error {
 	netInitScript := `#!/bin/sh
 # Poll Firecracker MMDS for network config, apply it, then exit.
 # Runs in background; loops until MMDS responds (survives snapshot resume).
+ip link set eth0 up 2>/dev/null
+ip route add 169.254.169.254 dev eth0 2>/dev/null
 ip addr add 169.254.169.2/32 dev eth0 2>/dev/null
 while true; do
   ip=$(wget -q -T1 -O- http://169.254.169.254/ip 2>/dev/null | tr -d '"')
@@ -179,12 +181,6 @@ done
 		return err
 	}
 
-	// write fc-net-init
-	os.MkdirAll(filepath.Join(mnt, "sbin"), 0o755)
-	if err := os.WriteFile(filepath.Join(mnt, "sbin", "fc-net-init"), []byte(netInitScript), 0o755); err != nil {
-		return err
-	}
-
 	if distro == "alpine" {
 		// write init script
 		initScript := `#!/bin/sh
@@ -208,10 +204,10 @@ ip route add 169.254.169.254 dev eth0 2>/dev/null
 		// systemd-based distributions (Debian, Ubuntu)
 		svc := `[Unit]
 Description=Firecracker Network Init
-After=network.target
+After=basic.target
 
 [Service]
-Type=oneshot
+Type=simple
 ExecStart=/sbin/fc-net-init
 RemainAfterExit=yes
 
@@ -229,10 +225,33 @@ WantedBy=multi-user.target
 		os.MkdirAll(wantsDir, 0o755)
 		os.Symlink("/etc/systemd/system/fc-net-init.service", filepath.Join(wantsDir, "fc-net-init.service")) //nolint:errcheck
 
-		// Ensure serial console is active
-		gettyWantsDir := filepath.Join(mnt, "etc", "systemd", "system", "getty.target.wants")
-		os.MkdirAll(gettyWantsDir, 0o755)
-		os.Symlink("/lib/systemd/system/serial-getty@.service", filepath.Join(gettyWantsDir, "serial-getty@ttyS0.service")) //nolint:errcheck
+		// Mask serial-getty@ttyS0.service and the udev device unit it depends on.
+		// In Firecracker, udev never runs so dev-ttyS0.device never activates,
+		// causing a 90-second systemd timeout. We replace it entirely with a
+		// custom service that uses ConditionPathExists (filesystem check) instead.
+		systemdDir := filepath.Join(mnt, "etc", "systemd", "system")
+		os.Symlink("/dev/null", filepath.Join(systemdDir, "serial-getty@ttyS0.service")) //nolint:errcheck
+		os.Symlink("/dev/null", filepath.Join(systemdDir, "dev-ttyS0.device"))          //nolint:errcheck
+
+		// Custom console service: no udev dependency, autologin as root.
+		consoleSvc := `[Unit]
+Description=Serial Console (ttyS0)
+After=basic.target
+ConditionPathExists=/dev/ttyS0
+
+[Service]
+ExecStart=/sbin/agetty --autologin root --noclear ttyS0 vt220
+Restart=always
+RestartSec=1
+
+[Install]
+WantedBy=multi-user.target
+`
+		consoleSvcPath := filepath.Join(systemdDir, "fc-console.service")
+		os.WriteFile(consoleSvcPath, []byte(consoleSvc), 0o644) //nolint:errcheck
+		wantsDir2 := filepath.Join(systemdDir, "multi-user.target.wants")
+		os.MkdirAll(wantsDir2, 0o755)
+		os.Symlink("/etc/systemd/system/fc-console.service", filepath.Join(wantsDir2, "fc-console.service")) //nolint:errcheck
 
 		// Clear root password for auto-login on console
 		shadowPath := filepath.Join(mnt, "etc", "shadow")
@@ -249,6 +268,11 @@ WantedBy=multi-user.target
 			}
 			os.WriteFile(shadowPath, []byte(strings.Join(lines, "\n")), 0o640) //nolint:errcheck
 		}
+
+		// Write fstab so systemd mounts virtual filesystems at boot.
+		// Minimal tarball rootfs has no fstab; without it /proc, /sys, /dev are not mounted.
+		fstab := "proc\t/proc\tproc\tdefaults\t0 0\nsysfs\t/sys\tsysfs\tdefaults\t0 0\ndevtmpfs\t/dev\tdevtmpfs\tdefaults\t0 0\n"
+		os.WriteFile(filepath.Join(mnt, "etc", "fstab"), []byte(fstab), 0o644) //nolint:errcheck
 	}
 	return nil
 }
@@ -363,8 +387,15 @@ func (o *Orchestrator) Golden(tag string, distro string) error {
 			[]byte(fmt.Sprintf("%d", cmd.Process.Pid)), 0o644)
 	}
 
-	o.log.Info("golden VM booted, letting it settle ...")
-	time.Sleep(3 * time.Second)
+	settleTime := 3 * time.Second
+	if distro == "debian" || distro == "ubuntu" {
+		// systemd takes significantly longer to reach multi-user.target than
+		// Alpine's busybox init. Snapshot too early and serial-getty@ttyS0
+		// won't have started yet, leaving the console unresponsive on resume.
+		settleTime = 20 * time.Second
+	}
+	o.log.Infof("golden VM booted, letting it settle (%s) ...", settleTime)
+	time.Sleep(settleTime)
 
 	// pause
 	o.log.Info("pausing golden VM ...")
@@ -494,6 +525,7 @@ func (o *Orchestrator) spawnOne(id int, net bool, tag string) error {
 	goldenDir := o.goldenDir(tag)
 	cloneDir := filepath.Join(o.clonesDir(), strconv.Itoa(id))
 	os.MkdirAll(cloneDir, 0o755)
+	os.WriteFile(filepath.Join(cloneDir, "tag"), []byte(tag), 0o644) //nolint:errcheck
 
 	sockPath := filepath.Join(cloneDir, "api.sock")
 	os.Remove(sockPath)
@@ -707,7 +739,7 @@ func installUbuntuPackages(mnt string, logger *log.Entry) error {
 		os.WriteFile(filepath.Join(mnt, "etc/resolv.conf"), data, 0o644) //nolint:errcheck
 	}
 
-	pkgs := "bash curl iproute2 wget ca-certificates"
+	pkgs := "bash curl iproute2 wget ca-certificates systemd systemd-sysv util-linux"
 	script := "DEBIAN_FRONTEND=noninteractive apt-get update -q && " +
 		"DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends " + pkgs + " && " +
 		"apt-get clean && rm -rf /var/lib/apt/lists/*"

orchestrator/serve.go

@@ -49,9 +49,9 @@ func Serve(orch *Orchestrator, addr string) error {
 	mux.HandleFunc("/clones", func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case http.MethodGet, "":
-			ids := runningCloneIDs(orch.cfg)
+			clones := runningClones(orch.cfg)
 			w.Header().Set("Content-Type", "application/json")
-			json.NewEncoder(w).Encode(ids) //nolint:errcheck
+			json.NewEncoder(w).Encode(clones) //nolint:errcheck
 		case http.MethodPost:
 			// Optional JSON body: {"net": bool, "tag": string}
 			// Defaults to the server's FC_AUTO_NET_CONFIG setting.
@@ -215,14 +215,19 @@ func bridgeWS(ws *websocket.Conn, consoleConn net.Conn, resizeConn net.Conn) {
 	<-sockDone
 }
 
-// runningCloneIDs returns clone IDs that have a live console socket.
-func runningCloneIDs(cfg Config) []int {
+type cloneEntry struct {
+	ID  int    `json:"id"`
+	Tag string `json:"tag"`
+}
+
+// runningClones returns entries for clones that have a live console socket.
+func runningClones(cfg Config) []cloneEntry {
 	clonesDir := filepath.Join(cfg.BaseDir, "clones")
 	entries, err := os.ReadDir(clonesDir)
 	if err != nil {
 		return nil
 	}
-	var ids []int
+	var clones []cloneEntry
 	for _, e := range entries {
 		if !e.IsDir() {
 			continue
@@ -232,11 +237,16 @@ func runningCloneIDs(cfg Config) []int {
 			continue
 		}
 		sock := filepath.Join(clonesDir, e.Name(), "console.sock")
-		if _, err := os.Stat(sock); err == nil {
-			ids = append(ids, id)
+		if _, err := os.Stat(sock); err != nil {
+			continue
 		}
+		tag := "unknown"
+		if raw, err := os.ReadFile(filepath.Join(clonesDir, e.Name(), "tag")); err == nil {
+			tag = strings.TrimSpace(string(raw))
 		}
-	return ids
+		clones = append(clones, cloneEntry{ID: id, Tag: tag})
+	}
+	return clones
 }
 
 func writeWSError(ws *websocket.Conn, msg string) {

orchestrator/web/terminal.html

@@ -62,6 +62,11 @@
     }
     .clone-entry button.destroy:hover { background: #2a1a1a; }
     .clone-entry button.destroy:disabled { color: #555; cursor: default; }
+    .clone-tag {
+      font-size: .72rem;
+      color: #666;
+      margin-left: .4rem;
+    }
 
     #index .none { color: #666; font-size: .9rem; }
 
@@ -183,11 +188,11 @@
       noneEl.style.display = 'none';
       const li = document.createElement('li');
       li.className = 'clone-entry';
-      li.dataset.id = c;
+      li.dataset.id = c.id;
       li.innerHTML =
-        `<a href="/?id=${c}">clone ${c}</a>` +
-        `<button class="destroy" title="Destroy clone ${c}">✕</button>`;
-      li.querySelector('.destroy').addEventListener('click', () => destroyClone(c, li));
+        `<a href="/?id=${c.id}">clone ${c.id}<span class="clone-tag">${c.tag}</span></a>` +
+        `<button class="destroy" title="Destroy clone ${c.id}">✕</button>`;
+      li.querySelector('.destroy').addEventListener('click', () => destroyClone(c.id, li));
       ul.appendChild(li);
     }