If the cluster is running Bright 9.2 and using Ubuntu 22.04 for the nodes that are part of the Kubernetes cluster, then you may notice that DNS resolution inside Kubernetes containers is failing.
# kubectl exec -i -t dnsutils — nslookup www.google.com
This behavior is due to an upstream issue with Ubuntu 22.04. The /etc/network/if-up.d/resolved file will need to be changed on all Ubuntu 22.04 nodes that are part of the Kubernetes cluster as follows:
# diff /etc/network/if-up.d/resolved.orig /etc/network/if-up.d/resolved 47c47 < "$DNS"="$NEW_DNS" --- > $DNS="$NEW_DNS" 51c51 < "$DOMAINS"="$NEW_DOMAINS" --- > $DOMAINS="$NEW_DOMAINS"
…where resolved.orig is the original resolved file that comes with Ubuntu 22.04 and resolved is the corrected file.
The nodes will then need to be rebooted.
Afterward, DNS resolution within Kubernetes containers should work.