PRE-CACHE tool | Assisted installer agent forces to remove a precached container image

When running ZTP to install SNO, there is an script called /usr/local/bin/agent-fix-bz1964591 that forces the removal of an assisted service container image if it is available locally. 

This causes the precache tool to always pull the container image from a registry even if the image is already available locally.

Always

1. Set up the precache ZTP flow by downloading the proper artifacts
2. Configure the siteconfig with the proper ZTP configuration for precaching. That includes a couple of ignitionOverrides to modify the discovery ISO.
2.
3.

The assisted installer agent image is always removed and then pulled from network

Since the agent container image is already available locally, there is no need to be pulled. The removal of this container image should be optional.

There is a workaround, which is basically override the script that removes the container image. This is done via an ignitionConfigOverrides. Example:

https://gitlab.cee.redhat.com/sysdeseng/5g-ericsson/-/blob/cnf-integration/demos/ztp-policygen/site-configs/clus3a-t5g-lab.yaml#L31

The script ends up being modified and looks like:

data:,#!/usr/bin/sh# This script is a workaround for bugzilla 1964591 where symlinks inside /var/lib/containers/ get
# corrupted under some circumstances.
#
# In order to let agent.service start correctly we are checking here whether the requested
# container image exists and in case "podman images" returns an error we try removing the faulty
# image.
#
# In such a scenario agent.service will detect the image is not present and pull it again. In case
# the image is present and can be detected correctly, no any action is required.IMAGE=$(echo $1 | sed 's/:.*//')
podman image exists $1 || echo "already loaded" || echo "need to be pulled"
#podman images | grep $IMAGE || podman rmi --force $1 || true