Docker build to spawn selenium standalone servers with Chrome and Firefox

• selenium-server-standalone
• google-chrome-stable
• firefox (stable)
• VNC access (useful for debugging the container)
• fluxbox (lightweight window manager for X)

1. Build this image

Ensure you have the Ubuntu base image downloaded, this step is optional since docker takes care of downloading the parent base image automatically, but for the sake of curiosity:

sudo docker run -i -t ubuntu:14.04 /bin/bash

If you don't git clone this repo, you can simply build from github:

sudo docker build github.com/elgalu/docker-selenium
ID=$(sudo docker images -q | sed -n 1p)
sudo docker tag $ID elgalu/docker-selenium:latest

If you git clone this repo locally, i.e. cd into where the Dockerfile is, you can:

sudo docker build -t="elgalu/docker-selenium:local" .

If you prefer to download the final built image from docker you can pull it, personally I always prefer to build them manually except for the base images like Ubuntu 14.04:

docker pull -t="elgalu/docker-selenium:latest" elgalu/docker-selenium

2. Use this image

e.g. Spawn a container for Chrome testing:

CH=$(sudo docker run --rm --name=ch -p=127.0.0.1::4444 -p=127.0.0.1::5900 \
    -v /e2e/uploads:/e2e/uploads elgalu/docker-selenium:local)

Note -v /e2e/uploads:/e2e/uploads is optional in case you are testing browser uploads on your webapp you'll probably need to share a directory for this.

The 127.0.0.1:: part is to avoid binding to all network interfaces, most of the time you don't need to expose the docker container like that so just localhost for now.

I like to remove the containers after each e2e test with --rm since this docker container is not meant to preserve state, spawning a new one is less than 3 seconds. You need to think of your docker container as processes, not as running virtual machines if case you are familiar with vagrant.

A dynamic port will be binded to the container ones, i.e.

# Obtain the selenium port you'll connect to:
docker port $CH 4444
#=> 127.0.0.1:49155

# Obtain the VNC server port in case you want to look around
docker port $CH 5900
#=> 127.0.0.1:49160

In case you have RealVNC binary vnc in your path, you can always take a look, view only to avoid messing around your tests with an unintended mouse click or keyboard.

./bin/vncview 127.0.0.1:49160

e.g. Spawn a container for Firefox testing:

This command line is the same as for Chrome, remember that the selenium running container is able to launch either Chrome or Firefox, the idea around having 2 separate containers, one for each browser is for convenience plus avoid certain :focus issues you web app may encounter during e2e automation.

FF=$(sudo docker run --rm --name=ff -p=127.0.0.1::4444 -p=127.0.0.1::5900 \
    -v /e2e/uploads:/e2e/uploads elgalu/docker-selenium:local)

Look around

sudo docker images
#=>

REPOSITORY               TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
elgalu/docker-selenium   local               1c68c8823418        2 minutes ago       1.065 GB
ubuntu                   14.04               e54ca5efa2e9        2 weeks ago         276.1 MB