Access service running in KIND (Kubernetes in Docker)

A show case on how to export your local port, so you can access the application and service running in KIND (kubernetes in docker)

Steps

• create kind cluster

$ git clone https://github.com/ozbillwang/kind-deployment-port-demo.git
$ cd kind-deployment-port-demo

$ brew install kind
$ kind create cluster --config kind-config.yaml

Make sure you can see the nodes

$ kubectl get nodes

NAME                 STATUS   ROLES    AGE   VERSION
kind-control-plane   Ready    master   19m   v1.18.2
kind-worker          Ready    <none>   19m   v1.18.2

Make sure the port has been redirected from host to kind worker's container

$ docker ps

CONTAINER ID        IMAGE                  COMMAND                  CREATED             STATUS              PORTS                       NAMES
06fc7e02d4b6        kindest/node:v1.18.2   "/usr/local/bin/entr…"   20 minutes ago      Up 20 minutes       0.0.0.0:80->32000/tcp       kind-worker
2a06cdabe9c7        kindest/node:v1.18.2   "/usr/local/bin/entr…"   20 minutes ago      Up 20 minutes       127.0.0.1:63527->6443/tcp   kind-control-plane

From above output, host port 32000 has been redirected from kind worker's port 80

deploy nginx service

$ kubectl apply -f https://k8s.io/examples/controllers/nginx-deployment.yaml

# check if nginx pods are running
$ kubectl get pods

NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-6b474476c4-4r2gw   1/1     Running   0          23m
nginx-deployment-6b474476c4-8z2ds   1/1     Running   0          23m
nginx-deployment-6b474476c4-h9b5m   1/1     Running   0          23m

Using a Service to Expose Your App

$ kubectl apply -f service.yaml

$ kk get service
NAME               TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes         ClusterIP   10.96.0.1      <none>        443/TCP        24m
nginx-deployment   NodePort    10.103.49.97   <none>        80:32000/TCP   16m

$ kk get ep
NAME               ENDPOINTS                                   AGE
kubernetes         172.18.0.3:6443                             30m
nginx-deployment   10.244.1.2:80,10.244.1.3:80,10.244.1.4:80   22m

Access nginx service

Access http://localhost

Explanation

• Export port 3200 in kind configuration, so your host's port 3200 will be redirected to kind worker's port 32000
• use a service to expose your application (nginx), from port 32000 to deployment port 80 to 3 nginx pods.

Now you are fine to access it from your host directly via http://localhost, the whole path would be

localhost:80 -> kind worker (a container) port 32000) -> via service (nginx-deployment) -> deployment port 80 > three pods with selector app=nginx

Reference

https://kubernetes.io/docs/concepts/workloads/controllers/deployment/