There are a few steps required to decommission a buildbot master.

• disable the master in Slavealloc: https://secure.pub.build.mozilla.org/slavealloc/ui/#masters
• shutdown it down to prevent Puppet from spamming us
• remove it from puppet repository
  • manifests/moco-nodes.pp
• remove the master from sysadmin Puppet repository (git-internal.mozilla.org/sysadmins/puppet.git)
  • modules/nagios4/manifests/prod/releng/scl3.pp
• remove it from tools repository
  • buildfarm/maintenance/production-masters.json
• delete the master from buildslaves DB
• once our part of the process is done, we'll also need to file a bug against MOC:Service Requests for decommissioning that master

Useful bug examples

• bug 1376279
• bug 1383266