We need to update the base reference platform we perform the
functional tests on. Debian bullseye seems like the best choice -- it
is recent enough to last for a while, and will match the
nodepool-builder container environment.
Depends-On: https://review.opendev.org/c/zuul/zuul-jobs/+/814088
Change-Id: Ic68e8c5b839cbc2852326747c68ef89f630f26a3
This is a base element which uses a containerfile (Dockerfile) to
build a container image, then the filesystem is extracted from that
image and forms the root of the dib image.
You can add as little or as much to the dockerfile as desired.
Change-Id: I4e821aa2ce7feb8841ef31da56de1a31aa9218b5