Readme.md

Managing Deployment, Scaling and Rolling updates

1. Download the deployment deploy-1.yaml file using following command:

   On Windows Powershell '-Outfile' is used for target filename, please replace it with '-o' on Mac or Linux Bash

   BASH

   $ wget -outfile deploy-1.yaml https://raw.githubusercontent.com/mahendra-shinde/kubernetes-demos/master/09-deployment/deploy-1.yaml
   
   

   Windows Powershell

   iwr -outfile deploy-1.yaml https://raw.githubusercontent.com/mahendra-shinde/kubernetes-demos/master/09-deployment/deploy-1.yaml
   

2. Now, run following commands to deploy.

   # Deploy
   $ kubectl apply -f deploy-1.yaml
   # Verify the deployment
   $ kubectl get deploy deploy1
   $ kubectl get rs -l app=web1
   $ kubectl get pods -l app=web1

3. Try scaling deployment through command line

   $ kubectl scale deploy deploy1 --replicas=5  
   $ kubectl get deploy
   $ kubectl get rs -l app=web1

4. Now, lets try rolling update. Try changing yaml file and update image version from 1 to 2 using CLI.

   # Update container image for 'web' container for deployment 'deploy1'
   $ kubectl set  image deploy/deploy1 web=mahendrshinde/myweb:2
   # View the rollout status, pod status and replica-sets
   $ kubectl rollout  status deploy/deploy1  
   $ kubectl get pods -l app=web1
   $ kubectl get rs -l app=web1

5. Undo the last change (revert to last version) using following command:

   $ kubectl rollout undo deploy/deploy1    
   $ kubectl rollout status deploy/deploy1
   # View all replica sets along with image tags
   $ kubectl get rs -l app=web1 -o wide

6. View the rollout history

   $ kubectl rollout history -f deploy-1.yaml

7. Performing rolling update using declarative option (editing deploy-1.yaml) Open deploy-1.yaml and replace mahendrshinde/myweb:1 to mahendrshinde/myweb:3 Use following command to apply changes and view rollout history.

   $ kubectl apply -f deploy-1.yaml --record
   $ kubectl rollout history -f deploy-1.yaml
   $ kubectl get rs -o wide -l app=web1

the extra option --record records the current command and use it as change-cause for rollout history.