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TASK 101: ReplicationController in Kubernetes

Start:         2022-12-22 19:57:05
Finished:   2023-02-15 20:57:16

Requirements​

The Nautilus DevOps team wants to create a ReplicationController to deploy several pods. They are going to deploy applications on these pods, these applications need highly available infrastructure. Below you can find exact details, create the ReplicationController accordingly.

  • Create a ReplicationController using httpd image, preferably with latest tag, and name it as httpd-replicationcontroller.

  • Labels app should be httpd_app, and labels type should be front-end.

  • The container should be named as httpd-container and also make sure replica counts are 3.

  • All pods should be running state after deployment.

Note: The kubectl utility on jump_host has been configured to work with the kubernetes cluster.

Note

This document focuses on the implementation approach. The task statement in Requirements is preserved as the source requirement.

Prerequisites​

  • Access to the configured Kubernetes cluster from jump_host.
  • kubectl is configured and points to the correct context.
  • Use the task-specified namespace, resource names, and images exactly.

Steps​

Check the existing resources.

kubectl get all

Create the replica-controller.yml file based on the requirements.

apiVersion: v1
kind: ReplicationController
metadata:
  name: httpd-replicationcontroller
  labels:
    app: httpd_app
    type: front-end
spec:
  replicas: 3
  selector:
    app: httpd_app
  template:
    metadata:
      labels:
        app: httpd_app
        type: front-end
    spec:
      containers:
        - name: httpd-container
          image: 
            httpd:latest
          ports:
            - containerPort: 80   
kubectl apply -f replica-controller.yml

Verify.

$ kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
httpd-replicationcontroller-dpv59   1/1     Running   0          33s
httpd-replicationcontroller-fchkz   1/1     Running   0          33s
httpd-replicationcontroller-hdzw5   1/1     Running   0          33s

Verification​

  • Confirm the required pods/services/deployments/jobs are in the expected state.
  • Run kubectl get commands for the affected resource types and namespace.

Resources​