iridium was phabricator, has been replaced by phab1001.
after a grace period, start decom'ing with all the steps.. not yet though
 - all system services confirmed offline from production use
 - set all icinga checks to maint mode/disabled while reclaim/decommmission takes place.
 - remove system from all lvs/pybal active configuration
 - any service group puppet/heira/dsh config removed
 - remove site.pp (replace with role::spare if system isn't shut down immediately during this process.)
START NON-INTERRUPPTABLE STEPS
 - disable puppet on host
 - remove all remaining puppet references (include role::spare) https://gerrit.wikimedia.org/r/#/c/366877/
 - power down host
 - disable switch port
 - switch port assignment noted on this task (for later removal) asw-b-eqiad:ge-1/0/16
 - remove production dns entries https://gerrit.wikimedia.org/r/#/c/366878/
 - puppet node clean, puppet node deactivate, salt key removed
END NON-INTERRUPPTABLE STEPS
 - system disks wiped (by onsite)
 - system unracked and decommissioned (by onsite), update racktables with result
 - switch port configration removed from switch once system is unracked.
 - mgmt dns entries removed.