Now available: Nested virtualization support on Depot CI sandboxes

Depot aims to be the fastest and most versatile CI out there, which means constantly shipping the features people are asking for.

We also build Depot on Depot, so most of what we ship is something we end up using ourselves.

Nested virtualization is no exception: it's been one of our most requested features for a while, and turning it on unlocks a lot of use cases for our users and for our own team.

Use cases

The most obvious use case is running the Android Emulator at native speed for tests, but nested virtualization opens up plenty of others: spinning up VMs for end-to-end tests (a full Kubernetes cluster, for example), running QEMU/KVM workloads inside a job, or doing hypervisor development.

Since the emulator is the headline use case, Depot CI ships with a ton of Android tooling out of the box. The base image ships with the full Android SDK surface preloaded, so you can target almost any combination of API level, architecture, and form factor without installing anything at build time.

Emulator system images

Available for API 10 through 36 (plus 36.1, 37.0, Baklava, CinnamonBun, CANARY), across:

Architectures: arm64-v8a, x86_64, x86, armeabi-v7a (plus MIPS on very old API levels)
Form factors: phone, tablet, Android TV, Google TV, Wear OS (3 through 6.1), Android Automotive (including Distant Display), Android Desktop, Google Play XR
Variants: default, google_apis, google_apis_playstore, aosp_atd, google_atd, plus pre-release 16 KB page-size builds for API 35+

Build and command-line tools

Build-tools: every release from 19.1.0 through 37.0.0-rc2, including RC builds for 32, 34, 35, 36, and 37
Platform-tools: 37.0.0
Command-line tools: versions 1.0 through 20.0, plus latest
Emulator: 36.5.11

Native development

NDK (side-by-side): every release from 16.1.4479499 through 30.0.14904198 rc1
NDK bundle: 22.1.7171670 for legacy setups
CMake: 3.6, 3.10, 3.18, 3.22, 3.30.x, 3.31.x, 4.0.x, 4.1.x

API levels and sources

Stable platforms: android-7 through android-36
Extension SDKs: 33-ext4/5, 34-ext8/10/11/12, 35-ext14/15, 36-ext18/19
Versioned previews: android-36.1, android-37.0
Codename previews: Baklava (with ext19), CinnamonBun (with ext23), CANARY
Sources: every release from android-15 through android-37.0

Extras

Google Play services, Google Repository, Android Support Repository, Android Auto Desktop Head Unit, Android Auto API Simulators, Google Web Driver, Play Licensing Library, Play APK Expansion library.

How to get started

Nested virtualization is enabled by default on every Depot CI sandbox, with no extra configuration and no extra cost. That said, we recommend at least a 4 vCPU sandbox type for reasonable emulator performance.

To help you get started, we put together a small example workflow that installs the Android tooling, boots the emulator, and runs Gradle tests against it. Depot Cache handles the Gradle cache so subsequent runs stay fast.

permissions:
  contents: 'read'
  id-token: 'write'

jobs:
  android-espresso-test:
    runs-on: depot-ubuntu-24.04-4
    steps:
      - name: Checkout repo
        uses: actions/checkout@v4

      - name: Set up JDK
        uses: actions/setup-java@v3
        with:
          distribution: 'zulu'
          java-version: '17'

      - name: Setup Gradle
        uses: gradle/actions/setup-gradle@v4

      - name: Setup Android SDK
        uses: android-actions/setup-android@v3

      - name: Install emulator and system image
        run: sdkmanager "emulator" "system-images;android-34;google_apis;x86_64"

      - name: Create AVD
        run: |
          echo "no" | avdmanager create avd \
            -n test_avd \
            -k "system-images;android-34;google_apis;x86_64" \
            --device "pixel_6" \
            --force

      - name: Start emulator
        run: |
          "${ANDROID_HOME}/emulator/emulator" -avd test_avd \
            -no-window -no-audio -no-boot-anim \
            -gpu swiftshader_indirect -accel on &

      - name: Wait for emulator boot
        run: |
          "${ANDROID_HOME}/platform-tools/adb" wait-for-device
          timeout 300 bash -c 'while [[ "$("${ANDROID_HOME}/platform-tools/adb" shell getprop sys.boot_completed 2>/dev/null)" != "1" ]]; do sleep 5; echo "  still booting..."; done'
          echo "=== Emulator booted ==="
          "${ANDROID_HOME}/platform-tools/adb" shell getprop ro.build.version.sdk
          "${ANDROID_HOME}/platform-tools/adb" shell getprop ro.product.cpu.abi

      - name: Disable animations
        run: |
          "${ANDROID_HOME}/platform-tools/adb" shell settings put global window_animation_scale 0
          "${ANDROID_HOME}/platform-tools/adb" shell settings put global transition_animation_scale 0
          "${ANDROID_HOME}/platform-tools/adb" shell settings put global animator_duration_scale 0

      - name: Configure Depot build cache
        run: |
          mkdir -p ~/.gradle/init.d
          cat > ~/.gradle/init.d/depot-cache.gradle << 'EOF'
          gradle.settingsEvaluated { settings ->
            settings.buildCache {
              remote(HttpBuildCache) {
                url = "https://cache.depot.dev"
                enabled = true
                push = true
                credentials {
                  username = ""
                  password = System.getenv("DEPOT_TOKEN") ?: ""
                }
              }
            }
          }
          EOF
          echo "org.gradle.caching=true" >> ui/espresso/BasicSample/gradle.properties

      - name: Run Espresso instrumented tests
        env:
          DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
        run: |
          cd ui/espresso/BasicSample
          ./gradlew connectedAndroidTest

      - name: Cleanup emulator
        if: always()
        run: adb emu kill 2>/dev/null || true

What's next

We're always keen to hear how we can make Depot better for the people building on it, so don't hold back: tell us what you're shipping, what's frustrating, or what you wish worked differently. If you run into any issues with nested virtualization or have ideas for making it more useful, reach out on our Discord community or open a support ticket. Happy building!

Peter Hasko-Nagy

Staff Engineer at Depot