Comment 10 for bug 1846535

EOD update from the cloud-init team:

We've identified what the problem is: in the problematic code path, we have started filtering out network devices that have a "master", which accidentally also includes physical interfaces that are members of a bridge or bond. As suggested in comment #1, it's the "net: add is_master check for filtering device list" commit that introduced the issue. Unfortunately, that commit was a fix for a critical issue (bug 1844191) from another source, so we cannot simply revert it and take our time to land a different fix.

We are currently pursuing three potential options for fixes: (a) completely circumvent the now-incorrect function in the code path that is raising the exception, (b) specifically avoid excluding bridge and bond member interfaces from the list, and (c) match more closely on the type of interface the 'master' check was intended to exclude. In order of preference, we would prefer (c) over (b) over (a). (Because (a) does not obviate the need for something along the lines of (b) or (c) for other code paths, and because we may have to play whack-a-mole with other cases that (b) needs to expand to include.)

We have initial implementations of (a) and (b) which we are testing (though they are not yet ready to land in trunk in their current form). We are investigating (c), but it's likely that we won't reach a conclusion on that investigation fast enough to warrant waiting for its completion before addressing this issue.