ClusterIP

ClusterIP is the default Kubernetes service. Your service will be exposed on a ClusterIP unless you manually define another type.

A ClusterIP provides network connectivity within your cluster. It can’t normally be accessed from outside. You use these services for internal networking between your workloads.

apiVersion: v1
kind: Service
spec:
  selector:
    app: my-app
  type: ClusterIP
  ports:
    - name: http
      port: 80
      targetPort: 80
      protocol: TCP

This example manifest defines a ClusterIP service. Traffic to port 80 on the ClusterIP will be forwarded to port 80 at your pods (targetPort). Pods with the app: my-app metadata field will be added to the service.

You can see the IP address that’s been assigned by running kubectl get services. Other workloads in your cluster can use this IP address to interact with your service.

image of Kubectl output showing a ClusterIP service

You can manually set a ClusterIP to a specific IP address using the spec.clusterIp field:

spec:
  type: ClusterIP
  clusterIp: 123.123.123.123

The clusterIp value must be a valid IP address within the range configured for your cluster. This is defined by the service-cluster-ip-range setting in the Kubernetes API server.