title: The Google Cloud Logging driver for Docker
body: <p>I'm not able to authenticate the google cloud driver <code>gcplogs</code> for Docker despite the fact that I've set the env var <code>GOOGLE_APPLICATION_CREDENTIALS</code> to the path/file where the JSON credentials of my service account is. The error message is the following:</p>
  
  <pre><code>ERROR: for oncrm_oncrm_1  Cannot start service oncrm: failed to initialize logging driver: google.DefaultTokenSource: google: could not find default credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.
  </code></pre>
  
  <p>The configuration I'm using on docker-compose is:</p>
  
  <pre><code>logging:
        driver: gcplogs
        options:
          gcp-project: "gcloud-project-id"
          gcp-meta-name: "prod-helpsec-01"
          labels: "app"
  </code></pre>
  
  <p>The enviroment I'm trying to run the docker container is:</p>
  
  <ul>
  <li><code>docker-ce v18.03</code></li>
  <li><code>docker-compose v1.21.0</code></li>
  <li><code>Ubuntu 17.10</code></li>
  </ul>