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.

 

REPLICATION CONTROLLER CREATION

  • Log in to the kubernetes master server through putty.

Steps to create a Replication Controller using YAML

 

  • Create a YAML file using the default editor.

Steps to create a Replication Controller using YAML

 

  • 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

Steps to create a Replication Controller using YAML

 

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

Syntax: kubectl apply -f <filename with extension>

Example: kubectl apply -f rc.yml

Steps to create a Replication Controller using YAML

 

  • Command executed successfully.

Steps to create a Replication Controller using YAML

 

  • All the PODs will be in creating status.

Steps to create a Replication Controller using YAML

 

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

Steps to create a Replication Controller using YAML

 

VERIFYING REPLICATION CONTROLLER

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

kubectl get rc

Steps to create a Replication Controller using YAML

 

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 <replication controller name>

Example: kubectl describe rc rep-pod

Steps to create a Replication Controller using YAML

Steps to create a Replication Controller using YAML

 

DELETING THE REPLICATION POD

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

Steps to create a Replication Controller using YAML

 

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

Steps to create a Replication Controller using YAML

 

  • 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.

Steps to create a Replication Controller using YAML

 

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

Steps to create a Replication Controller using YAML

Steps to create a Replication Controller using YAML

 

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.



Author: Loges
Logeswaran holds Microsoft certified engineer & solution architect certifications with over 11+ years of experience in the fields of hosting technologies and IMS/Cloud consulting. At AssistanZ, Logeswaran spearheads the strategic planning and execution of the company’s Microsoft based core technologies to Enterprise clients.

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