Docker for Visual Regression Testing (VRT)

We are using a Docker image to perform visual regression testing, so that we get consistent results regardless of the host-OS that is running the test.

Installing Docker for Mac

Follow the instructions to install Docker for Mac

Install the VRT image

docker pull uglow/backstopjs

Make sure you allocate enough memory (more than 2GB) to Docker. You can change this in your Docker Preferences (in OSX).

Using the image

See CONTRIBUTING.md.

The base commands in package.json are listed below:

# On OSX:
docker run --rm -v $PWD:/src/ -it --add-host dockerhost:`ipconfig getifaddr en0` uglow/backstopjs test --config=config/testVisualRegression/backstop.ci.config.js

# ON Linux:
docker run --rm -v $PWD:/src/ -it --add-host dockerhost:`/sbin/ip route|awk '/default/ { print  $3}'` uglow/backstopjs test --config=config/testVisualRegression/backstop.ci.config.js

The reason for two different commands is that there are OS-specific ways to get the HOST IP address and pass it to the container.

Debugging the image

docker run --rm -v $PWD:/src/ -it --entrypoint=/bin/bash uglow/backstopjs

Rebuilding the image

You would only ever need to rebuild the image if you are changing it. Once you change it you also need to publish it.

Changing the image

Open a terminal and navigate into the config/docker directory
Edit Dockerfile as required
Run docker build

Publishing the image

Hopefully one day there will be a local AusPost repo. Until then, you will need your own Docker account to publish to the global registry.

Create a Docker account on https://hub.docker.com/
Run docker login locally, and enter your Docker credentials
Run docker image push <image>:latest

uglow / backstopjs