21 June 2023
k8s internal virtual network uses dns to allow pods and services to communicate via domains instead of ips.
dns runs as a service in the cluster as a pod.
pod-ip-address.namespace-name.pod.cluster.local
pod-ip-address is ip separated by - instead of .
example:
Pod with 192.169.10-100 ip in default namespace will have dns as
192-168-10-100.default.pod.cluster.local
service-name.namespace-name.svc.cluster-domain.example
default cluster domain is cluster.local
a serice FQDN can be used to reach service from any namespace in the cluster.
To access a service in the same namespace only service name can be used.