<p>Right now, I can add my ip using</p>
<pre><code>gcloud container clusters update core-cluster --zone=asia-southeast1-a --enable-master-authorized-networks --master-authorized-networks w.x.y.z/32
</code></pre>
<p>but it overrides all the existing authorized networks that was already there.</p>
<p>Is there any way to append the new ip to the existing list of authorized networks?</p>

<p>You could automate what @Gari Singh said using gcloud, jq and tr. See below for doing it with CLI:</p>
<pre class="lang-bash prettyprint-override"><code>NEW_CIDR=8.8.4.4/32
export CLUSTER=test-psp
OLD_CIDR=$(gcloud container clusters describe $CLUSTER --format json | jq -r '.masterAuthorizedNetworksConfig.cidrBlocks[] | .cidrBlock' | tr '\n' ',')
echo &quot;The existing master authorized networks were $OLD_CIDR&quot;
gcloud container clusters update $CLUSTER --master-authorized-networks &quot;$OLD_CIDR$NEW_CIDR&quot; --enable-master-authorized-networks
</code></pre>
