Steps to create a Replication Controller using YAML

In this blog, We will show you the Steps to create a Replication Controller using YAML in Kubernetes Environment.

REQUIREMENTS

• 2 Node Cluster ( 1 Master VM with 2 Nodes)

• Kubernetes Components

INFRASTRUCTURE OVERVIEW

• We have already installed and configured the 2 Node cluster in our demo environment.

• Please check the URL https://www.assistanz.com/steps-to-install-kubernetes-cluster-manually-using-centos-7/ for more information

REPLICATION CONTROLLER CREATION

• Log in to the kubernetes master server through putty.

• Create a YAML file using the default editor.

• Add the below coding and save it.

apiVersion: v1 kind: ReplicationController metadata:     name: rep-pod spec:     replicas: 4     selector:        app: web        env: test     template:        metadata:           labels:              app: web              env: test        spec:           containers:           - name: rep-cont             image: nginx

• Execute the below command to create a replication controller using YAML file.

Syntax: kubectl apply -f

Example: kubectl apply -f rc.yml

• Command executed successfully.

• All the PODs will be in creating status.

• After few seconds, all the PODs are in running status.

VERIFYING REPLICATION CONTROLLER

• Use the below command to view the list of replication controllers.

kubectl get rc

Note: rc is the short-hand of replication controller

• Describe command will use to view the detailed information about the replication controller.

Syntax: kubectl describe rc

Example: kubectl describe rc rep-pod

DELETING THE REPLICATION POD

• Currently, there are four POD’s available in our demo replication controller.

• Let’s delete a POD and see how kubernetes reacts.

• Kubernetes will start creating a new POD automatically. Kubernetes will keep on checking the desired state. When the desired state fails, kubernetes takes own action to restore the state.

• After few seconds, the new POD is in running status and replaced the old one.

EXTERNAL LINKS

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

VIDEO

Thanks for reading this blog. We hope it was useful for you learn about creating a replication controller using YAML file in the kubernetes environment.