2 min read | by Jordi Prats
To be able to expose a given Service externally, we can use NodePort as a quick-and-dirty way of achieving it. NodePort Services use a port on each Node to expose the Service outside of the cluster network
Using a Service of type NodePort is as easy of changing an existing service type to NodePort. For instance, for an existing ClusterIP service we can change the type on the spec section to NodePort:
apiVersion: v1 kind: Service metadata: labels: app: demo name: demo namespace: default spec: ports: - name: web port: 80 protocol: TCP targetPort: 80 selector: app: demo type: NodePort Getting the list of services we will be able to see that the type have changed and on the PORT(S) column we will be able to see the exposed port, on the following example it is 30431:
$ kubectl get svc demo NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE demo NodePort 10.100.20.98 <none> 80:30431/TCP 2d1h This port can also set to a specific port using nodePort on the spec.ports section:
spec: ports: - name: http nodePort: 31070 port: 9000 protocol: TCP targetPort: 9000 This port must be withing a given range, by default this range is: 30000-32767 so be advised that you can't set it to port 80 by default.
Posted on 02/03/2021