feature & bug: Pre-loading images in Airgap mode

[hoangphuocbk]

Summary

Description

When I upgrade RKE2 version on our cluster, steps in airgap mode are described as below

1. Copy tarball images from local to remote servers
2. Rolling restart RKE2 services node by node

However if the version of some components need to be upgraded such as cilium, ingress, etc... Helm release will be upgraded when first RKE2 service on server node is restarted. Then that causes ImagePullBackOff error on server & agent nodes which are not restarted yet.

Proposal

Add the rke2_airgap_preloading_image flag variable, that allow us to pre-load images on all nodes in cluster from tarball image files after this step https://github.com/lablabs/ansible-role-rke2/blob/main/tasks/rke2.yml#L128-L134

Benefits

1. Fix my report bug, that avoids downtime when upgrade important components such as CNIs.
2. Reduce time when install and upgrade cluster, because images are already imported. Pre-loading images are quicker because it can be done in parallel when compare with import images in restarting RKE2 services orderly.

Issue Type

Feature Idea

[simonfelding]

already exists #301 (comment)

[hoangphuocbk]

Auto import images is supported as k3s-io/k3s#11563