[devel at bb.net] Taking knuth.r.igoro.us offline

[Dustin J. Mitchell]

We've been using a worker in my basement for quite some time to run
Buildbot's tests in the metabuildbot.  It's time for that server to be
retired -- its power consumption is costing me about as much as an
equivalent cloud instance these days, and I'm not fully utilizing it.

The buildbot-linux4 worker, hosted at Mozilla, is running exactly the
same set of builders -- most critically, db-postgres and db-mysql.  So
I don't think shutting this worker off will leave us without any
functionality loss.  However, I don't expect that host to last
forever, either -- Mozilla's IT has been on a corporatist cost-cutting
tear for a few years now and eventually they'll remember that little
VM in the corner.

The advantage of these two hosts is that they have very reliable
connections (I have a business line at home) and they have MySQL and
Postgres DB's on them.  Moreover, they aren't used for other things,
so unrelated upgrades don't tend to break the buildbot functionality.
These days, we could probably address the latter issue with Docker
containers, putting the buildbot-worker in one container and MySQL and
Postgres in others.

This would be a great time for one of the other organizations using
Buildbot to set up a similar host.  I'd be happy to draft up the
Docker images, if that helps.

Dustin