title: Deploy a specific subfolder with cloud-run github action when working with a monorepo
body: <p>I am working with a mono repo and I would like to deploy my back-end (only) with the Cloud Run service (using the &quot;official&quot; <a href="https://github.com/google-github-actions/deploy-cloudrun" rel="nofollow noreferrer">google cloud run action</a>). For this action, I need a Dockerfile at the root of my project for building my image. But my Dockerfile is under <code>./server</code>.</p>
  <p>Is there a way to use something like <code>working-directory</code> for the <code>run</code> steps ? I didn't find anything from the doc.</p>
  <p>Or do I have to have a Dockerfile at the root of my project and the Dockerfile points to the <code>./server</code>?</p>
  <p>My project tree :</p>
  <pre><code>./
   .github/
     worflows/
       deploy-back.yml
    client/
      ...
    server/
      ...
      Dockerfile
  </code></pre>
  <pre class="lang-yaml prettyprint-override"><code># deploy-back.yml
  name: Deploy to production
  
  # ...
  
  jobs:
    deployment-job:
      runs-on: ubuntu-latest
      environment: production
      steps:
        - uses: actions/checkout@v2
        - name: Authenticate to Google Cloud
          uses: google-github-actions/auth@v0
          with:
            # ...
        - name: Deploy to Cloud Run
          uses: google-github-actions/deploy-cloudrun@v0
          with:
            service: ${{ env.SERVICE_NAME }}
            source: gcr.io/${{ env.PROJECT_ID }}/${{ env.SERVICE_NAME }}:${{ env.PACKAGE_VERSION }}
            project_id: ${{ env.PROJECT_ID }}
            region: ${{ env.RUN_REGION }}
            tag: ${{ env.PACKAGE_VERSION }}
  
  </code></pre>