title: How to get all defined secrets in gitlab-ci?
body: <p>Is it possible to print all defined secrets (or at least their keys) in a <code>gitlab_ci.yml</code> script?</p>
  <p>Pseudocode:</p>
  <pre><code>deploy:
    stage: deploy
    script: |
            for KEY in $SECRETS
               echo $KEY
            done
  </code></pre>