When I run linkerd check --proxy I get the next error:
cluster networks contains all services
the Linkerd clusterNetworks ["10.0.0.0/8,100.64.0.0/10,172.16.0.0/12,192.168.0.0/16"] do not include svc my-namespace/postgres-database ()
see https://linkerd.io/2.12/checks/#l5d-cluster-networks-pods for hints
The service in question has type type: ExternalName and should not be monitored by linkerd.
The official docs https://linkerd.io/2.12/checks/#l5d-cluster-networks-pods are not very helpful. To remedy this, update the clusterNetworks setting. However, I did not find any information how clusterNetworks can be configured in Linkerd
This error appeared after the upgrade to Linkerd 2.12
It was a bug in linkerd 2.12 and should be fixed soon. https://github.com/linkerd/linkerd2/discussions/9814