Buildduty is responsible for reconfig-ing the Buildbot masters to get release engineering code changes into production.
The person doing reconfigs should also update the reconfig deployments page.
Scheduled reconfigs are *supposed* to happen every Monday and Thursday. During this, buildduty needs to merge default -> production branches and reconfig the affected masters. The Landing Buildbot Master Changes wiki page has step by step instructions.
It is also valid to do other additional reconfigs anytime you want. Other release engineers may have important changes to land that don't coincide with the scheduled reconfigs.
It is polite to ask in #mozbuild if anyone has further changes to land before starting the reconfig process.
While merging buildbot-configs default -> production and buildbotcustom default -> production-0.8, merge mozharness default -> production as well.
If there are changes to tools that impact the foopies, you should update to the latest version of code on the foopies.
How to reconfig
You should use Fabric to do the reconfig. That's kind of old school and error prone. Even better - use the script pmoore wrote. It's full of awesome. Unicorns too. bug 1018248 See https://hg.mozilla.org/build/tools/file/default/buildfarm/maintenance/end_to_end_reconfig.sh end_to_end_reconfig.sh
Help, my reconfig is stuck!
If the reconfig gets stuck, see How To/Unstick a Stuck Slave From A Master.