Puppet has been disabled on iridium (The server hosting phabricator.wikimedia.org) for some time now due to broken deployment configuration.
We (Myself and Ariel) are going to attempt to re-enable puppet today at 20:00 UTC (Noon, Pacific), taking advantage of the lower than normal level of activity on Phabricator due to the US Holiday. There shouldn't be any noticeable downtime, however, phabricator might respond with 5xx errors or become unresponsive for a short time around 20:10. Maintenance should be finished before 20:30.
I apologize for the short notice, this should have been sent out on Friday. Although I do not expect this to cause any issues, please do let me know if you notice any new issues after the maintenance is complete.