auto-pull images by default?

[jmarrero]

While the aim of this project is to run local containers to iterate on, in many cases we can start a VM to test an already shipped feature or perform a smoke test on an image built by CI in the cloud.

Instead of failing, we could pull the container using Podman or Skopeo and issue a warning such as: “Container not found locally, pulling from remote source.

[jmarrero]

@alicefr reported this, WDYT @cgwalters? If you hold strongly that we should error out, this can be just modifying the error message a bit?

[cgwalters]

This is a very complex topic. Kubelet has slightly different rules for this than docker/podman: https://kubernetes.io/docs/concepts/containers/images/#updating-images

I'd be fine changing it to pull-by-default, but it was intentional to not do so. If we do start pulling, then we definitely want to expose --pull=<policy>.