Rolling update

There are 3 major update methods for the services running inside k8s:

1. Rolling update
2. Blue/Green
3. Canary

I will not repeat them since there is a very good article there:

https://searchitoperations.techtarget.com/answer/When-to-use-canary-vs-blue-green-vs-rolling-deployment

For rolling update, Google has an introduction here:

https://cloud.google.com/kubernetes-engine/docs/how-to/updating-apps

There are multiple ways to use rolling update:

• 'kubectl set image'
• Use new image (through terraform either from command line or Gitlab)

Some considerations for a successful rolling update:

• Backward compatible
• Testing
• Rollback strategy
• Timing