title: Docker Compose bind mount doesn't work in GitHub Actions
body: <p>If I run a Docker Compose command in GitHub Actions which uses a bind mount, it says the source directory doesn't exist. Here's the error.</p>
  
  <pre><code>Cannot create container for service chat: invalid mount config for type "bind": bind source path does not exist: /__w/omni-chat/omni-chat
  </code></pre>
  
  <p>I think the issue is that the root directory is incorrectly being passed to GitHub Actions. I specified the absolute path as the conventional <code>.</code>, but I don't know what caveats GitHub Actions has regarding that.</p>
  
  <p>Here's a simplified version of my workflow.</p>
  
  <pre class="lang-yaml prettyprint-override"><code>on: push
  jobs:
    test-server:
      runs-on: ubuntu-latest
      container: docker/compose
      steps:
        - uses: actions/checkout@v2
        - run: docker-compose run --rm chat gradle test
  </code></pre>
  
  <p>Here's a simplified version of my Docker Compose file.</p>
  
  <pre class="lang-yaml prettyprint-override"><code>version: '3.7'
  services:
    chat:
      image: gradle:6.3-jdk8
      command: bash
      volumes:
        - type: bind
          source: .
          target: /home/gradle
        - type: volume
          source: gradle-cache
          target: /home/gradle/.gradle
  volumes:
    gradle-cache:
  </code></pre>
  
  <p>If you need the full details, here's the <a href="https://github.com/neelkamath/omni-chat/actions/runs/65646164" rel="nofollow noreferrer">exact run</a>.</p>