title	description
Kubernetes - Rollback Deployment	Learn and Implement Kubernetes Rollback Deployment

Step-00: Introduction

• We can rollback a deployment in two ways.
  • Previous Version
  • Specific Version

Step-01: Rollback a Deployment to previous version

Check the Rollout History of a Deployment

# List Deployment Rollout History
kubectl rollout history deployment/<Deployment-Name>
kubectl rollout history deployment/my-first-deployment  

Verify changes in each revision

• Observation: Review the "Annotations" and "Image" tags for clear understanding about changes.

# List Deployment History with revision information
kubectl rollout history deployment/my-first-deployment --revision=1
kubectl rollout history deployment/my-first-deployment --revision=2
kubectl rollout history deployment/my-first-deployment --revision=3

Rollback to previous version

• Observation: If we rollback, it will go back to revision-2 and its number increases to revision-4

# Undo Deployment
kubectl rollout undo deployment/my-first-deployment

# List Deployment Rollout History
kubectl rollout history deployment/my-first-deployment  

Verify Deployment, Pods, ReplicaSets

# Verify Deployment, Pods, ReplicaSets
kubectl get deploy
kubectl get rs
kubectl get po
kubectl describe deploy my-first-deployment

Access the Application using Public IP

• We should see Application Version:V2 whenever we access the application in browser

# Get Load Balancer IP
kubectl get svc

# Application URL
http://<External-IP-from-get-service-output>

Step-02: Rollback to specific revision

Check the Rollout History of a Deployment

# List Deployment Rollout History
kubectl rollout history deployment/<Deployment-Name>
kubectl rollout history deployment/my-first-deployment 

Rollback to specific revision

# Rollback Deployment to Specific Revision
kubectl rollout undo deployment/my-first-deployment --to-revision=3

List Deployment History

• Observation: If we rollback to revision 3, it will go back to revision-3 and its number increases to revision-5 in rollout history

# List Deployment Rollout History
kubectl rollout history deployment/my-first-deployment

Access the Application using Public IP

• We should see Application Version:V3 whenever we access the application in browser

# Get Load Balancer IP
kubectl get svc

# Application URL
http://<Load-Balancer-IP>

Step-03: Rolling Restarts of Application

• Rolling restarts will kill the existing pods and recreate new pods in a rolling fashion.

# Rolling Restarts
kubectl rollout restart deployment/<Deployment-Name>
kubectl rollout restart deployment/my-first-deployment

# Get list of Pods
kubectl get po