noVNC scaled correctly but the emulator's Qt window opened small (~411x914) and floated inside the 1080x2280 Xvfb, so the user saw a tiny phone in a sea of black. v8 bakes a background fitter (wmctrl+xdotool) that, after boot, auto-OKs the one-shot nested-virtualization warning dialog, fills the phone window to the display, and parks the control strip off the right edge — re-running to catch window/dialog timing then maintaining every 30s. Applied live to the running pod already; this makes it survive the next wake. |
||
|---|---|---|
| .. | ||
| docker | ||
| gate.py | ||
| gate.tf | ||
| main.tf | ||
| README.md | ||
| secrets | ||
| terragrunt.hcl | ||
| variables.tf | ||
android-emulator — shared in-cluster Android testing instance
Android 16 (API 36, google_apis/x86_64) emulator running under KVM in the
cluster, so agents can natively test app/PWA changes before shipping (first
tenant: tripit). Decision record: docs/adr/0001-android-emulator-in-cluster.md.
On-demand lifecycle (since 2026-06-12)
The emulator scales to zero when idle (no adb/VNC connections for ~1h,
checked by the android-emulator-idle-sleeper CronJob) and wakes on
visit: the wake gate owns / on both hostnames. Warm boot is ~90s.
-
Humans: open https://android-emulator.viktorbarzin.me — it wakes the emulator if needed, shows a self-refreshing boot page, then hands over to the noVNC screen.
-
Agents (before adb): wake + poll, then connect:
curl -ks --resolve android-emulator.viktorbarzin.lan:443:10.0.20.203 https://android-emulator.viktorbarzin.lan/wake until curl -ks --resolve android-emulator.viktorbarzin.lan:443:10.0.20.203 https://android-emulator.viktorbarzin.lan/status | grep -q '"ready": 1'; do sleep 5; done adb connect 10.0.20.200:5555
Endpoints
| What | Where |
|---|---|
| adb | adb connect 10.0.20.200:5555 (LAN only; adb is unauthenticated — never expose publicly) |
| Screen (noVNC) | https://android-emulator.viktorbarzin.lan/vnc.html (LAN only) |
Agent quickstart (from a devvm)
# one-time: user-local platform-tools
wget -qO /tmp/pt.zip https://dl.google.com/android/repository/platform-tools-latest-linux.zip
unzip -q /tmp/pt.zip -d ~/android-sdk # → ~/android-sdk/platform-tools/adb
adb="$HOME/android-sdk/platform-tools/adb"
$adb connect 10.0.20.200:5555
$adb -s 10.0.20.200:5555 install app-debug.apk # install an APK
$adb -s 10.0.20.200:5555 shell am start -a android.intent.action.VIEW -d https://tripit.viktorbarzin.me # open a URL
$adb -s 10.0.20.200:5555 shell input tap 540 1200 # drive the UI
$adb -s 10.0.20.200:5555 exec-out screencap -p > /tmp/screen.png # screenshot
The emulator is a single shared instance — adb shell pm list packages,
uninstall your test app when done, and presence-claim
(presence claim service:android-emulator) for long destructive sessions
(wipes, system-image changes).
How it works
- The container image (built from
docker/) holds only JDK 17, cmdline-tools, emulator native libs, Xvfb/x11vnc/noVNC and socat — ~1GB. - The SDK proper (platform-tools, emulator, system image, AVD, snapshots)
lives on the
android-emulator-sdkPVC (proxmox-lvm); the entrypoint installs it idempotently. First boot downloads ~2.5GB (≈9GB unpacked on the PVC) and takes ~15 min (startup probe allows 30); subsequent restarts boot in ~1–2 min. - The emulator runs on the GPU node (k8s-node1) with a T4 time-slice (qemu holds ~100 MiB VRAM while awake; scale-to-zero keeps it transient). Guest GL is deliberately SOFTWARE (llvmpipe): rendering into Xvfb pins GL to the X stack, and true NVIDIA headless GL would need -no-window plus the emulator's own streaming instead of x11vnc — not worth it at the measured CPU numbers below.
Rebuilding the image (rare — tool/library bumps only)
cd stacks/android-emulator/docker
docker build -t forgejo.viktorbarzin.me/viktor/android-emulator:<new-tag> .
docker push forgejo.viktorbarzin.me/viktor/android-emulator:<new-tag>
# then bump var.image_tag default in variables.tf and land via CI
Built manually from a devvm on purpose: it changes rarely, and a one-off push doesn't warrant CI plumbing (the off-infra-CI rule targets repeated build IO).
Troubleshooting
- Pod CrashLoops with
FATAL: /dev/kvm not present→ node lost the device or the privileged/Kyverno exclude regressed (android-emulatormust be insecurity_policy_exclude_namespaces, stacks/kyverno). - Wedged Android (won't boot, storage full) → delete the PVC + pod: next boot re-downloads cleanly. Snapshots/AVD state are disposable by design.
- Different API level: set
API_LEVELenv on the deployment (entrypoint installs that system image on the same PVC) or recreate the AVD.
Resource profile (measured 2026-06-12, v6 on node1)
- Asleep (scaled to zero): nothing — the gate (~10m CPU/13Mi) is the only standing cost.
- Awake: settles to ~0.5–1.3 cores with a static screen (on or off), ~4.8–5.2 Gi memory (limit 8 Gi, requests 3 Gi), ~100 MiB T4 VRAM. Boot bursts 5–9 cores for the first few minutes (dex2oat etc.).
- Disk: ~7 G of the 30 Gi PVC.
- Etiquette still applies for long sessions with animated content:
adb -s 10.0.20.200:5555 shell input keyevent KEYCODE_SLEEPwhen done.
Remote access
https://android-emulator.viktorbarzin.me (Cloudflare-proxied, Authentik-gated) serves the same noVNC screen for off-LAN use. adb stays LAN-only by design.