Running tests against PostgreSQL in a service container#

I wanted to run some Django tests - using pytest-django and with Django configured to pick up the DATABASE_URL environment variable via dj-database-url - against a PostgreSQL server running in GitHub Actions.

It took a while to figure out the right pattern. The trick was to define a postgres: service and then set the DATABASE_URL environment variable to the following:

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postgres://postgres:postgres@127.0.0.1:${{ job.services.postgres.ports['5432'] }}/dbname

Here’s my full .github/workflows/test.yml:

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name: Run tests
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on: [push]
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jobs:
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  test:
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    runs-on: ubuntu-latest
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    services:
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      postgres:
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        image: postgres:12
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        env:
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          POSTGRES_USER: postgres
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          POSTGRES_PASSWORD: postgres
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          POSTGRES_DB: dbname
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        options:
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          --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
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        ports:
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        - 5432:5432
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    steps:
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    - uses: actions/checkout@v2
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    - name: Set up Python
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      uses: actions/setup-python@v2
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      with:
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        python-version: 3.8
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    - uses: actions/cache@v2
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      name: Configure pip caching
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      with:
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        path: ~/.cache/pip
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        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
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        restore-keys: |
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          ${{ runner.os }}-pip-
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    - name: Install dependencies
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      run: |
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        pip install -r requirements.txt
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    - name: Run tests
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      env:
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        DATABASE_URL: postgres://postgres:postgres@127.0.0.1:${{ job.services.postgres.ports['5432'] }}/dbname
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      run: |
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        cd myproject
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        pytest

And against MySQL#

I had to figure this out against MySQL as well for db-to-sqlite - here’s the workflow test.yml file I ended up with. Key extract here:

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    services:
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      mysql:
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        image: mysql
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        env:
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          MYSQL_ALLOW_EMPTY_PASSWORD: yes
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          MYSQL_DATABASE: test_db_to_sqlite
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        options: >-
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          --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
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        ports:
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          - 3306:3306
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    # ...
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    - name: Run tests
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      env:
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        MYSQL_TEST_DB_CONNECTION: mysql://root@127.0.0.1:${{ job.services.mysql.ports['3306'] }}/test_db_to_sqlite
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      run: pytest -vv