when I run kubectl get deploy/my-deploy -o yaml > my-deployment.yaml and modify only the container image tag, and run kubectl apply with the fixed file, is there a command that I can check whether the configured deployment is ready or not?
When I create a new deployment by changing both the image tag AND the deployment name, I check the new deployment’s readiness by checking the .status.conditions[] and selecting the reason MinimumReplicasAvailable. However this is not possible in the case above because the MinimumReplicasAvailable already meets (As the original one before modifying the image tag is already alive).
Any helps or suggestions ?
If I understood the issue correctly, this command will do your job.
kubectl rollout status deployment/my-deployIt will output you with the current deployment rollout status.
Waiting for rollout to finish: 2 out of 3 new replicas have been updated...
or
deployment "my-deploy" successfully rolled out
Reference: https://kubernetes.io/docs/concepts/workloads/controllers/deployment/
The field that indicates how many pods are updated is the status.updatedReplicas.
According to the documentation, this is the meaning of that field:
Total number of non-terminated pods targeted by this deployment that have the desired template spec.
This means you should be able to tell when a Deployment rollout is complete by comparing spec.Replicas with status.updatedReplicas. When they match the rollout is complete.