How do I force Kubernetes to re-pull an image?

Kubernetes will pull upon Pod creation if either (see updating-images doc):

• Using images tagged :latest
• imagePullPolicy: Always is specified

This is great if you want to always pull. But what if you want to do it on demand: For example, if you want to use some-public-image:latest but only want to pull a newer version manually when you ask for it. You can currently:

• Set imagePullPolicy to IfNotPresent or Never and pre-pull: Pull manually images on each cluster node so the latest is cached, then do a kubectl rolling-update or similar to restart Pods (ugly easily broken hack!)
• Temporarily change imagePullPolicy, do a kubectl apply, restart the pod (e.g. kubectl rolling-update), revert imagePullPolicy, redo a kubectl apply (ugly!)
• Pull and push some-public-image:latest to your private repository and do a kubectl rolling-update (heavy!)

No good solution for on-demand pull. If that changes, please comment; I'll update this answer.

One has to group imagePullPolicy inside the container data instead of inside the spec data. However, I filed an issue about this because I find it odd. Besides, there is no error message.

So, this spec snippet works:

spec:  containers:  - name: myapp    image: myregistry.com/myapp:5c3dda6b    ports:    - containerPort: 80    imagePullPolicy: Always  imagePullSecrets:    - name: myregistry.com-registry-key

There is a comand to directly do that:

Create a new kubectl rollout restart command that does a rolling restart of a deployment.

The pull request got merged. It is part of the version 1.15 (changelog) or higher.