Emulator Cloud Docker Images

This repository contains the Docker build files used to create a browser-accessible Android emulator environment. It is organized as a layered image stack:

1. vnc-base: a Debian/Xfce desktop image with TigerVNC and noVNC.
2. emulator_cloud: an Android SDK, Android Emulator, and Appium image built on top of vnc-base.

The resulting container exposes a remote Linux desktop over VNC/noVNC and runs Appium for Android automation.

Repository Layout

.
|-- README.md
|-- build_dockerfile.py
|-- vnc/
|   |-- config.yml
|   |-- Dockerfile
|   |-- Makefile
|   `-- src/
|       |-- common/
|       |   |-- install/
|       |   |-- scripts/
|       |   `-- xfce/
|       `-- debian/
|           |-- install/
|           `-- icewm/
`-- android/
    |-- Dockerfile
    |-- Makefile
    |-- emulator_base
    `-- scripts/

Image Responsibilities

vnc/

Builds the reusable desktop base image from debian:11.

Included components:

• Xfce desktop environment
• TigerVNC server on port 5901
• noVNC web client on port 6901
• Chromium browser
• Locale, fonts, shell helpers, and non-root container user setup

The VNC startup script is vnc/src/common/scripts/vnc_startup.sh. It creates the VNC password file, starts noVNC, starts TigerVNC, launches the window manager, and keeps the container alive.

Default VNC settings:

Variable	Default
DISPLAY	:1
VNC_PORT	5901
NO_VNC_PORT	6901
VNC_RESOLUTION	1280x1024
VNC_COL_DEPTH	24
CONFIG_FILE	/home/fortinet/config.yml
VNC_PW	Optional runtime override
VNC_VIEW_ONLY	false

The VNC password is read from vnc/config.yml at build time and copied into the image as /home/fortinet/config.yml:

vnc:
  password: "change_me"

Update this value before building an image, or override it at runtime with -e VNC_PW=<password>. If neither VNC_PW nor vnc.password is configured, the container exits during startup.

android/

Builds the Android emulator automation image from vnc-base:latest.

Included components:

• OpenJDK 17
• Android SDK command-line tools
• Android Emulator
• Android platform tools
• Android API/system image packages
• Node.js, npm, Appium, and the Appium uiautomator2 driver
• Desktop shortcuts for launching emulator profiles

The current android/Dockerfile installs Android 35 packages:

• platforms;android-35
• build-tools;35.0.0
• system-images;android-35;google_apis;x86_64
• platform-tools

It creates an AVD named google_api, copies Android config into /home/fortinet/.android/, expects a snapshot directory at android/snapshot/api_1.0.36, and starts Appium by default:

appium --relaxed-security \
  --default-capabilities '{"newCommandTimeout": "0"}' \
  --log /home/fortinet/appium_log/appium.log \
  --base-path /wd/hub \
  --log-level debug

android/emulator_base appears to be an alternate or older base Dockerfile for Android API 34 setup.

Building Images

The Makefiles publish images to the internal registry 10.160.16.60/emulator-cloud.

Build the VNC base image:

cd vnc
make build_docker_image

Push the VNC base image:

cd vnc
make push_docker_image

Build the Android emulator image:

cd android
make build_docker_image

Push the Android emulator image:

cd android
make push_docker_image

The Android image Makefile pulls the base image before building:

BASE_IMAGE := 10.160.16.60/emulator-cloud/vnc-base:latest
DOCKER_IMAGE := 10.160.16.60/emulator-cloud/emulator_cloud:$(tag_name)

Running Locally

Example VNC base container:

docker run --rm -it \
  -p 5901:5901 \
  -p 6901:6901 \
  10.160.16.60/emulator-cloud/vnc-base:latest

Open the web desktop through noVNC:

http://localhost:6901/?password=<configured-password>

Example Android emulator/Appium container:

docker run --rm -it \
  -p 5901:5901 \
  -p 6901:6901 \
  -p 4723:4723 \
  10.160.16.60/emulator-cloud/emulator_cloud:<tag>

The Appium endpoint is available under:

http://localhost:4723/wd/hub

Depending on host configuration, Android emulator acceleration may require KVM/device access when running on Linux.

Versioning Convention

Image tags are intended to encode both image version and Android API level. The existing convention is:

<major>.<patch>.<api-level>

Example:

1.0.34

Meaning:

• 1: first major version of this image family
• 0: no patch-level image changes
• 34: Android API level

Check android/Makefile and android/Dockerfile together before releasing a new image. At the time of this README update, android/Makefile uses tag_name := 1.0.34, while android/Dockerfile installs Android 35 packages and references snapshot/api_1.0.36.

Supporting Scripts

• build_dockerfile.py: generates a separate emulator_docker_snapshot_ready sample Docker project and zip archive for a prebuilt Android 34 snapshot workflow.
• android/scripts/start_google_api.sh: launches the google_api AVD from the remote desktop.
• android/scripts/start_android_api.sh: launches an android_api AVD from the remote desktop, although the current Dockerfile creates google_api.
• vnc/src/common/scripts/chrome-init.sh: prepares Chromium startup settings based on the VNC environment.
• vnc/src/common/scripts/generate_container_user: configures nss_wrapper for arbitrary non-root container users.

Operational Notes

• noVNC: http://<host>:6901/?password=<VNC_PW>
• Native VNC: <host>:5901
• VNC password source: VNC_PW runtime environment variable, or vnc.password from /home/fortinet/config.yml
• Default container user: UID 1000
• Appium logs: /home/fortinet/appium_log/appium.log
• Internal image builder noted by the original README: Jenkins host 10.160.50.118
• Internal registry noted by the original README: 10.160.16.60

Maintenance Checklist

Before publishing a new Android image:

1. Confirm the Android API level in android/Dockerfile.
2. Confirm tag_name in android/Makefile matches the intended release/versioning convention.
3. Confirm any referenced snapshot directory exists under android/snapshot/.
4. Confirm vnc/config.yml has the intended VNC password for the image being released.
5. Build and run the VNC base image if its scripts changed.
6. Build and run the Android image, then verify:
   • noVNC login works.
   • Appium starts and listens on port 4723.
   • The expected AVD can be launched.
   • Appium can create a session against the emulator.