A simple example of how to start Docker in a macOS GitHub workflow. Take a look at the swift.yml file.
jobs:
build:
runs-on: macos-latest
steps:
- uses: actions/checkout@v2
- name: Build
run: swift build -v
- name: Install docker # Taken from https://github.com/actions/virtual-environments/issues/1143#issuecomment-652264388
run: |
mkdir -p ~/.docker/machine/cache
curl -Lo ~/.docker/machine/cache/boot2docker.iso https://github.com/boot2docker/boot2docker/releases/download/v19.03.12/boot2docker.iso
brew install docker docker-machine
docker-machine create --driver virtualbox default
docker-machine env default
- name: Run tests
run: |
eval "$(docker-machine env default)"
docker pull swift:5.3-amazonlinux2
swift test --enable-code-coverage --sanitize=threadThe Install docker step sets up the filesystem, uses brew to install docker-machine and starts docker-machine.
The Run tests step sets up the docker environment variables, pulls the image that we are going to use and runs the test. You want to pull the image that you will be using in the tests before running the tests because bandwidth is limited in the testing environment. You don't want your tests to run slowly while downloading the image. I have a had a race condition where I create some temp files, pull the image, continue with the test and the temp files end up being cleaned up and the test fails.