In the output of your cluster's Events, usually in the "kube-system" namespace, you might notice a series of warnings that resemble the following:
Search Line limits were exceeded, some search paths have been omitted, the applied search line is: kube-system.svc.cluster.local svc.cluster.local cluster.local my.domain.internal domain.internal my.domain
Solution
This is related to a known limitation in Kubernetes where only a total of six search domains are supported in a node's /etc/resolv.conf file. This includes the three that are automatically created by Kubernetes: kube-system.svc.cluster.local, svc.cluster.local, and cluster.local.
If this number is exceeded, Kubernetes will choose six domains to default to and ignore the rest, while printing this warning.
If you have defined more than three of your own custom search domains in your node's /etc/resolv.conf file, you can resolve this warning by reducing that amount.
After you have edited your resolv.conf file, you may need to restart the Kubelet and coredns deployment for the change to take effect in new pods:
On each node:
systemctl restart kubelet
On the machine where you run kubectl:
kubectl -n kube-system rollout restart deployment coredns