How to Access a Service in Another Namespace

#services #kubernetes #externalname #namespaces #dns #k8s

To access a Kubernetes Service in another namespace by a local name, use an ExternalName Service when a DNS alias is appropriate.

This creates a Service in the current namespace whose external name is another Service's Domain Name System (DNS) name:

kind: Service
apiVersion: v1
metadata:
  name: service-y
  namespace: namespace-a
spec:
  type: ExternalName
  externalName: service-y.namespace-b.svc.cluster.local
  ports:
  - port: 80

For simple access, Kubernetes resolves the DNS such as <service-name>.<namespace>.svc.cluster.local