title: How to start airflow-scheduler pod for Google Cloud Composer?
body: <p>A Composer cluster went down because its airflow-worker pods needed a Docker image that was not accessible.</p>
  <p>Now access to the Docker image was restore, but the <strong>airflow-scheduler pod has disappeared</strong>.</p>
  <p>I tried updating the Composer Environment by setting a new Environment Variable, with the following error :</p>
  <pre><code>UPDATE operation on this environment failed X minutes ago with the following error message: (404)
  Reason: Not Found
  HTTP response headers: HTTPHeaderDict({
    &quot;Date&quot;: &quot;recently&quot;,
    &quot;Audit-Id&quot;: &quot;my-own-audit-id&quot;,
    &quot;Content-Length&quot;: &quot;236&quot;,
    &quot;Content-Type&quot;: &quot;application/json&quot;,
    &quot;Cache-Control&quot;: &quot;no-cache, private&quot;
  })
  HTTP response body: {
    &quot;kind&quot;: &quot;Status&quot;,
    &quot;apiVersion&quot;: &quot;v1&quot;,
    &quot;metadata&quot;: {},
    &quot;status&quot;: &quot;Failure&quot;,
    &quot;message&quot;: &quot;deployments.apps \&quot;airflow-scheduler\&quot; not found&quot;,
    &quot;reason&quot;: &quot;NotFound&quot;,
    &quot;details&quot;: {
      &quot;name&quot;: &quot;airflow-scheduler&quot;,
      &quot;group&quot;: &quot;apps&quot;,
      &quot;kind&quot;: &quot;deployments&quot;
    },
    &quot;code&quot;: 404
  }
  
  Error in Composer Agent
  </code></pre>
  <p>How can I launch a airflow-scheduler pod on my Composer cluster ?</p>
  <p><strong>What is the <code>.yaml</code> configuration file I need to apply ?</strong></p>
  <p>I tried launching the scheduler from inside another pod with <code>airflow scheduler</code>, and while it effectively starts a scheduler, it's not a Kubernetes pod and will not integrate well with the managed airflow cluster.</p>