[x] Write a Horizon FAQ https://wikitech.wikimedia.org/wiki/Help:Horizon_FAQ
[x] Give users adequate notice of the change
[] Complete work on the Horizon proxy panel https://phabricator.wikimedia.org/T124183
-- at pre-scheduled time:
[x] Remove wikitech link 'Manage DNS Domains' (via MediaWiki:Sidebar/Group:cloudadmin)
[x] Disable/hide/remove wikitech link 'Manage Addresses' (via MediaWiki:Sidebar/Group:projectadmin)
[x] Disable/hide/remove wikitech link 'Manage Web Proxies' (via MediaWiki:Sidebar/Group:projectadmin)
[] Migrate existing ldap DNS to designate https://phabricator.wikimedia.org/T129272
[x] Create default domains for all projects (~andrew/projectdomains.py on californium)
[] change labs-ns0 and labs-ns1 to the new pdns hosts (labservices1001 and holmium)
[] Replace wikitech link 'Manage Addresses' as a link to https://horizon.wikimedia.org/project/dns_domains/
[] Replace wikitech link 'Manage We Proxies' as a link to https://horizon.wikimedia.org/project/proxy/
[] Announce
[] Clean-up: Turn off ldap/pdns servers