Step-00: Introduction¶

Why do we need Pausing & Resuming Deployments?
If we want to make multiple changes to our Deployment, we can pause the deployment make all changes and resume it.
We are going to update our Application Version from V3 to V4 as part of learning "Pause and Resume Deployments"

Step-01: Pausing & Resuming Deployments¶

Check current State of Deployment & Application¶

```t

Check the Rollout History of a Deployment¶

kubectl rollout history deployment/my-first-deployment
Observation: Make a note of last version number

Get list of ReplicaSets¶

kubectl get rs Observation: Make a note of number of replicaSets present.

Access the Application¶

http:// Observation: Make a note of application version

### Pause Deployment and Two Changes
```t
# Pause the Deployment
kubectl rollout pause deployment/<Deployment-Name>
kubectl rollout pause deployment/my-first-deployment

# Update Deployment - Application Version from V3 to V4
kubectl set image deployment/my-first-deployment kubenginx=stacksimplify/kubenginx:4.0.0 

# Check the Rollout History of a Deployment
kubectl rollout history deployment/my-first-deployment  
Observation: No new rollout should start, we should see same number of versions as we check earlier with last version number matches which we have noted earlier.

# Get list of ReplicaSets
kubectl get rs
Observation: No new replicaSet created. We should have same number of replicaSets as earlier when we took note. 

# Make one more change: set limits to our container
kubectl set resources deployment/my-first-deployment -c=kubenginx --limits=cpu=20m,memory=30Mi

Resume Deployment¶

# Resume the Deployment
kubectl rollout resume deployment/my-first-deployment

# Check the Rollout History of a Deployment
kubectl rollout history deployment/my-first-deployment  
Observation: You should see a new version got created

# Update REVISION CHANGE-CAUSE
kubectl annotate deployment/my-first-deployment kubernetes.io/change-cause="Deployment PAUSE RESUME Demo - App Version 4.0.0 "

# Check the Rollout History of a Deployment
kubectl rollout history deployment/my-first-deployment

# Get list of ReplicaSets
kubectl get rs
Observation: You should see new ReplicaSet.

# Get Load Balancer IP
kubectl get svc

Access Application¶

# Access the Application 
http://<External-IP-from-get-service-output>
Observation: You should see Application V4 version

Step-02: Clean-Up¶

# Delete Deployment
kubectl delete deployment my-first-deployment

# Delete Service
kubectl delete svc my-first-deployment-service

# Get all Objects from Kubernetes default namespace
kubectl get all