Exposing LoadBalancer service in minikube at arbitrary port?

Question

I have a minikube cluster with a running WordPress in one deployment, and MySQL in another. Both of the deployments have corresponding services. The definition for WordPress service looks like this:

apiVersion: v1
kind: Service
metadata:
    name: wordpress
spec: 
    selector:
        app: wordpress
    ports:
        - port: 80 
    type: LoadBalancer

The service works fine, and minikube service gives me a nice path, with an address of minikube ip and a random high port. The problem is WordPress needs a full URL in the name of the site. I'd rather not change it every single time and have local DNS name for the cluster.

Is there a way to expose the LoadBalancer on an arbitrary port in minikube? I'll be fine with any port, as long as it's port is decided by me, and not minikube itself?

Answer 1

Keep in mind that Minikube is unable to provide real loadbalancer like different cloud providers and it merely simulates it by using simple nodePort Service instead.

You can have full control over the port that is used. First of all you can specify it manually in the nodePort Service specification (remember it should be within the default range: 30000-32767):

If you want a specific port number, you can specify a value in the nodePort field. The control plane will either allocate you that port or report that the API transaction failed. This means that you need to take care of possible port collisions yourself. You also have to use a valid port number, one that’s inside the range configured for NodePort use.

Your example may look as follows:

apiVersion: v1
kind: Service
metadata:
    name: wordpress
spec: 
    selector:
        app: wordpress
    ports:
        - port: 80
          targetPort: 80
          nodePort: 30000
    type: NodePort

You can also change this default range by providing your custom value after --service-node-port-range flag when starting your kube-apiserver.

When you use kubernetes cluster set up by kukbeadm tool (Minikube also uses it as a default bootstrapper), you need to edit /etc/kubernetes/manifests/kube-apiserver.yaml file and provide the required flag with your custom port range.