tl;dr:
VMs created on or after September 8th will stop having .eqiad.wmflabs domains, and be found only under .eqiad1.wikimedia.cloud
The whole story:
Currently cloud-vps VMs stand astride two worlds: wmflabs and wikimedia.cloud. Here's the status quo:
- New VMs get three different DNS entries: hostname.project.eqiad1.wikimedia.cloud, hostname.project.eqiad.wmflabs, and hostname.eqiad.wmflabs [0]
- Reverse DNS lookups return hostnames under eqiad1.wikimedia.cloud
- VMs themselves believe (e.g. via hostname -f) that they're still under eqiad.wmflabs
That hybrid system has done a good job maintaining backwards compatibility, but it's a bit of a mess. In the interest of simplifying, standardizing, and eliminating ever more uses of the term 'labs', we're going to start phasing out the wmflabs domain name. Beginning on September 8th, new VMs will no longer receive any naming associated with .wmflabs [1].
- New VMs will get one DNS entry: hostname.project.eqiad1.wikimedia.cloud
- New VMs will continue to have a pointer DNS entry that refers to the .wikimedia.cloud name
- New VMs will be assigned an internal hostname under .wikimedia.cloud
In order to avoid breaking existing systems, these changes will NOT be applied retroactively to existing VMs. Old DNS entries will live on until the VM is deleted and should be largely harmless. If, however, you find yourself rewriting code in order to deal with VMs under both domains (due to the change in hostname -f behavior), don't worry -- adjusting an old VM to identify as part of .wikimedia.cloud only requires a simple change to /etc/hosts. I'll be available to make that change for any project that chooses consistency over backwards-compatibility.
[0] https://phabricator.wikimedia.org/phame/post/view/191/new_names_for_everyone