I have two kubernetes objects,

apiVersion: v1
kind: Pod
metadata:
  name: client-pod
  labels:
    component: web
spec:
  containers:
  - name: client
    image: stephengrider/multi-client
    resources:
      limits:
        memory: "128Mi"
        cpu: "500m"
    ports:
      - containerPort: 3000

apiVersion: v1
kind: Service
metadata:
  name: client-node-port
spec:
  type: NodePort
  selector:
    component: web
  ports:
  - port: 3050
    targetPort: 3000
    nodePort: 31515

and i applied both using kubectl apply -f <file_name> after that, here is the output

kubectl get services
NAME                  TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
client-node-port      NodePort    10.100.230.224   <none>        3050:31515/TCP   30m

the pod output

NAME                                  READY   STATUS    RESTARTS   AGE
client-pod                            1/1     Running   0          28m

but when i run minikube ip it returns 127.0.0.1, i'm using minikube with docker driver.

After following this issue https://github.com/kubernetes/minikube/issues/7344. i got the node-ip using

kubectl get node -o json |
        jq --raw-output \
          '.items[0].status.addresses[]
            | select(.type == "InternalIP")
              .address
          '

But even then i am not able to access the service. After more searching i find out

minikube service --url client-node-port
🏃  Starting tunnel for service client-node-port.
|-----------|------------------|-------------|------------------------|
| NAMESPACE |       NAME       | TARGET PORT |          URL           |
|-----------|------------------|-------------|------------------------|
| default   | client-node-port |             | http://127.0.0.1:52694 |
|-----------|------------------|-------------|------------------------|
http://127.0.0.1:52694
❗  Because you are using a Docker driver on darwin, the terminal needs to be open to run it.

i can access the service using minikube service.

Question:

1. But i want to know why the nodePort exposed didn't work ?
2. why did i do this workaround to access the application.

More Information:

minikube version
minikube version: v1.10.1
commit: 63ab801ac27e5742ae442ce36dff7877dcccb278

docker version
Client: Docker Engine - Community
 Version:           19.03.8
 API version:       1.40
 Go version:        go1.12.17
 Git commit:        afacb8b
 Built:             Wed Mar 11 01:21:11 2020
 OS/Arch:           darwin/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.8
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.17
  Git commit:       afacb8b
  Built:            Wed Mar 11 01:29:16 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.2.13
  GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

kubectl version
Client Version: version.Info{Major:"1", Minor:"16+", GitVersion:"v1.16.6-beta.0", GitCommit:"e7f962ba86f4ce7033828210ca3556393c377bcc", GitTreeState:"clean", BuildDate:"2020-01-15T08:26:26Z", GoVersion:"go1.13.5", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.2", GitCommit:"52c56ce7a8272c798dbc29846288d7cd9fbae032", GitTreeState:"clean", BuildDate:"2020-04-16T11:48:36Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}

if you need more info, i'm willing to provide.

minikube ssh

docker@minikube:~$ ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
4: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    inet 172.18.0.1/16 brd 172.18.255.255 scope global docker0
       valid_lft forever preferred_lft forever
945: eth0@if946: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default  link-netnsid 0
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever