<p>I have a cluster on GKE whose node pool I create when I want to use the cluster, and delete when I'm done with it.</p>

<p>It's a two node cluster with the master in <code>europe-west2-a</code> and with and whose node zones are <code>europe-west2-a</code> and <code>europe-west2-b</code>.</p>

<p>The most recent creation resulted in the node in zone B failing with <code>NetworkUnavailable</code> because <code>RouteController failed to create a route</code>. The reason was because <code>Could not create route xxx 10.244.1.0/24 for node xxx after 342.263706ms: instance not found</code>.</p>

<p>Why would this be happening all of a sudden, and what can I do to fix it?!</p>

yoitsro
<p>You didn't mention which version of GKE you are using so just for clarification:</p>

<blockquote>
  <p>Changes in <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/access-scopes#changes" rel="nofollow noreferrer">access scopes</a>
  Beginning with Kubernetes version 1.10, gcloud and GCP Console no longer grants the compute-rw access scope on new clusters and new node pools by default. Furthermore, if --scopes is specified in gcloud container create, gcloud no longer silently adds compute-rw or storage-ro.</p>
</blockquote>

<p>In any case you can still revert to legacy access scopes but this is not recommended approach.</p>

<p>Hope this help.</p>
