Running ReplicaSet on Kubernetes

Introduction

I was trying to understand the Replicaset and wanted to see if we can run it directly and can it be accessible like Deployment Resource.

ReplicaSet

The YAML for the replicaset is:

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: helloweb-rs
  labels:
    app: hello
spec:
  replicas: 3
  selector:
    matchLabels:
      app: hello
  template:
    metadata:
      labels:
        app: hello
    spec:
      containers:
       - name: hello-app
         image: gcr.io/google-samples/hello-app:1.0
         ports:
         - containerPort: 8080

I launched the 3 pods using the above YAML.

$ kubectl apply -f replicaset.yaml
replicaset.apps/helloweb-rs created

The status of the K8 cluster:

$ kubectl get all
NAME                    READY   STATUS    RESTARTS   AGE
pod/helloweb-rs-8grmh   1/1     Running   0          6s
pod/helloweb-rs-9bstq   1/1     Running   0          6s
pod/helloweb-rs-rzjc8   1/1     Running   0          6s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   42h

NAME                          DESIRED   CURRENT   READY   AGE
replicaset.apps/helloweb-rs   3         3         3       6s

Created load balancer service YAML

apiVersion: v1
kind: Service
metadata:
  name: helloweb-svc
  labels:
    app: hello
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: hello

Launched it via kubectl:

$ kubectl apply -f service-lb.yaml
service/helloweb-svc created

The status of the service

$ kubectl get all
NAME                    READY   STATUS    RESTARTS   AGE
pod/helloweb-rs-8grmh   1/1     Running   0          3m9s
pod/helloweb-rs-9bstq   1/1     Running   0          3m9s
pod/helloweb-rs-rzjc8   1/1     Running   0          3m9s

NAME                   TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/helloweb-svc   LoadBalancer   10.102.140.85   localhost     80:30971/TCP   6s
service/kubernetes     ClusterIP      10.96.0.1       <none>        443/TCP        42h

NAME                          DESIRED   CURRENT   READY   AGE
replicaset.apps/helloweb-rs   3         3         3       3m9s

Open the http://localhost/ in browser:

Happy Coding !!