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.

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-sdk PVC (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 renders via swiftshader (CPU) — deliberately NOT scheduled on the contended T4 GPU node.

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-emulator must be in security_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_LEVEL env on the deployment (entrypoint installs that system image on the same PVC) or recreate the AVD.

Resource profile (measured 2026-06-12)

Memory: ~5.8Gi steady (limit 8Gi, requests 3Gi — Burstable inside the tier-1 quota).
CPU: ~1.8 cores idle with the screen off; 5+ cores with the screen on (any on-screen animation forces continuous swiftshader rendering + VNC encoding). Etiquette: turn the screen off when you finish a session — adb -s 10.0.20.200:5555 shell input keyevent KEYCODE_POWER (and the same to wake it).
Disk: ~7G of the 30Gi PVC.

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.

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