<p>Anyone know what a <code>configmap cache</code> is by any chance?</p>
<p>Trying to debug a <code>failed to sync configmap cache</code> error here.</p>

<p>From the docs <a href="https://kubernetes.io/docs/concepts/configuration/configmap/#mounted-configmaps-are-updated-automatically" rel="nofollow noreferrer">here</a></p>
<blockquote>
<p>The kubelet uses its local cache for getting the current value of the
ConfigMap from Kubernetes API Server. The type of the cache is configurable using the
<em>ConfigMapAndSecretChangeDetectionStrategy</em> field in the
KubeletConfiguration struct. A ConfigMap can be either propagated by
watch (default), ttl-based, or simply redirecting all requests
directly to the API server. As a result, the total delay from the
moment when the ConfigMap is updated to the moment when new keys are
projected to the Pod can be as long as the kubelet sync period + cache
propagation delay, where the cache propagation delay depends on the
chosen cache type (it equals to watch propagation delay, ttl of cache,
or zero correspondingly)</p>
</blockquote>
<p><code>failed to sync configmap cache</code> could be because kubelet could not connect to Kubernetes API Server to get the updated configMap data. I would look into Kubelet logs using <code>journalctl -u kubelet</code></p>
