title: GitLab run pipeline only manually and not automatically
body: <p>My GitLab pipelines execute automatically on every push, I want to manually run pipeline and not on every push.</p>
  <p>Pipeline docs: <a href="https://docs.gitlab.com/ee/ci/yaml/#workflowrules" rel="noreferrer">https://docs.gitlab.com/ee/ci/yaml/#workflowrules</a><br></p>
  <p>I tried this in
  <strong>.gitlab-ci.yml</strong></p>
  <pre class="lang-yaml prettyprint-override"><code>workflow:
    rules:
      - when: manual    # Error: workflow:rules:rule when unknown value: manual
  </code></pre>