<p>How Can I enable batch/v2alpha1API for a google container engine cluster ? 
Which is by passing</p>

<p><code>--runtime-config=batch/v2alpha1=true</code> </p>

<p>to the API server .</p>

<p>I'm using version kubernetes 1.7.6.
Where should I go to enable that !!!</p>

<p>You cannot change the runtime configuration of the Kubernetes apiserver in Google Container Engine and by policy alpha APIs are not enabled because they have no official support policy. From <a href="https://kubernetes.io/docs/concepts/overview/kubernetes-api/" rel="nofollow noreferrer">https://kubernetes.io/docs/concepts/overview/kubernetes-api/</a>:</p>

<blockquote>
  <p>Alpha level:</p>
  
  <ul>
  <li>The version names contain alpha (e.g. v1alpha1).</li>
  <li>May be buggy. </li>
  <li>Enabling the feature may expose bugs.</li>
  <li>Disabled by default.</li>
  <li>Support for feature may be dropped at any time without notice.</li>
  <li>The API may change in incompatible ways in a later software release without notice.</li>
  <li>Recommended for use only in short-lived testing clusters, due to increased risk of bugs and lack of long-term support.</li>
  </ul>
</blockquote>

<p>If you want that particular alpha API enabled in Google Container Engine, you can create an <a href="https://cloud.google.com/container-engine/docs/alpha-clusters" rel="nofollow noreferrer">alpha cluster</a>.</p>
