Find internal DNS records on k8s - allanrogerr/public GitHub Wiki

Find internal DNS records on k8s

Find the ClusterIP of the kube-dns service

kubectl -n kube-system get svc kube-dns -o json | jq -r '.spec.clusterIP'

Output

10.43.0.10

Find the application service endpoint IP

kubectl -n hashicorp-vault get ep -o json | jq '.items[].subsets[] | select( .addresses[0].targetRef.name == "vault-0") | select( .addresses[0].hostname == "vault-0")' | jq -r '.addresses[0].ip'

Output

10.42.0.95

Exec into the debug pod

kubectl --namespace default exec -it ubuntu -- /bin/bash

Get DNS service name

nslookup 10.42.0.95 10.43.0.10

Output

95.0.42.10.in-addr.arpa	name = 10-42-0-95.vault.hashicorp-vault.svc.cluster.local.
95.0.42.10.in-addr.arpa	name = vault-0.vault-internal.hashicorp-vault.svc.cluster.local.