This is a clone of issue OCPBUGS-22175. The following is the description of the original issue:
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When the IPA image boots, there is no way of distinguishing it from any other CoreOS image (e.g. the actual booted cluster node) when looking at the console.

The image-customisation-controller should generate ignition that drops a file in /etc/issue.d/ (note that filenames must end with .issue) that tells the user they're looking at an IPA image.

e.g. the agent-based installer does this by overriding /etc/issue: https://github.com/openshift/installer/blob/master/data/data/agent/files/etc/issue.template

We should also set a MOTD for users who ssh in while we are at it, preferably overriding the one that CoreOS sets in /etc/motd that only makes sense in the context of a cluster node (I'm not sure if it's possible to override that one with Ignition though, we might have to settle for dropping it it /etc/motd.d.