title: Copy files from GCS into a Cloud Run docker container during build
body: <p>I am trying to use <code>gsutil</code> to copy a file from GCS into a Run container during the build step.</p>
  <p>The steps I have tried:</p>
  <pre><code>RUN pip install gsutil
  RUN gsutil -m cp -r gs://BUCKET_NAME $APP_HOME/artefacts
  </code></pre>
  <p>The error:</p>
  <pre><code>ServiceException: 401 Anonymous caller does not have storage.objects.get access to the Google Cloud Storage object.
  CommandException: 1 file/object could not be transferred.
  The command '/bin/sh -c gsutil -m cp -r gs://BUCKET_NAME $APP_HOME/artefacts' returned a non-zero code: 1
  ERROR
  ERROR: build step 0 &quot;gcr.io/cloud-builders/docker&quot; failed: step exited with non-zero status: 1
  </code></pre>
  <p>The service account (default compute &amp; cloudbuild) does have access to GCS, and I have also tried to <code>gsutil config -a</code> and with various other flags with no success!</p>
  <p>I am not sure on exactly how I should authenticate to successfully access the bucket.</p>