Kubernetes NodePort url getting changed with "minikube service <service>" - macos

Question

I have created a NodePort to forward request from port 30101->80->8089:
apiVersion: v1
kind: Service
metadata:
name: gorest-service
spec:
type: NodePort
selector:
app: gorest
ports:
- protocol: TCP
port: 80
targetPort: 8089
nodePort: 30101
When I try to get the service URL http://192.168.49.2:30101, I am unable to access it, but with url http://127.0.0.1:64741, retrieved by using minikube service <service>, I am able to access.
Query: Unable to understand how http://192.168.49.2:30101 was changed to http://127.0.0.1:64741 retrived by minikube service <service>
% minikube service gorest-service
|-----------|----------------|-------------|---------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|----------------|-------------|---------------------------|
| default | gorest-service | 8089 | http://192.168.49.2:30101 |
|-----------|----------------|-------------|---------------------------|
🏃 Starting tunnel for service gorest-service.
|-----------|----------------|-------------|------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|----------------|-------------|------------------------|
| default | gorest-service | | http://127.0.0.1:64741 |
|-----------|----------------|-------------|------------------------|
🎉 Opening service default/gorest-service in default browser...
❗ Because you are using a Docker driver on darwin, the terminal needs to be open to run it.

Answer 1

In your manifest file you remap the service port inside the container from port 80 to port 8089.
If you want to access that service inside kubernetes you have to use the 8089 port.
BUT you cannot access services inside K8s from the outside world: you need to expose them (you should use a load balancer or an egress service).
Minikube is meant to be used for development. The 64741 port you see is a tunnel service that starts minikube and allows you to test and debug your service outside k8s without using an egress (which might be doing more than just connecting the service with the outside world, like for instance authenticating or authorizing requests).

Answer 2

Your understanding is correct, service exposed using NodePort should be reachable on minikube_IP:NodePort. First I checked it on Linux VM with minikube installed and it worked.
Then I noticed you're using MacOS:
Because you are using a Docker driver on darwin
Which leads us to some limitations with minikube running with docker driver on MacOS. Please see this GitHub issue.
There are two options at least (more, but these are simple to do):
use minikube tunnel what you did and it worked for you.
Tunnel is used to expose the service from inside of VM where minikube is running to the host machine's network. Please refer to access applications in minikube. This is how minikube_IP:NodePort transforms to localhost:different_port.
start minikube with VirtualBox driver to get a proper IP (if you really need to access your service on NodePort), below the command how to start it with VirtualBox driver (this should be installed on your machine):
minikube start --driver=VirtualBox