I'd like to see if I can get some input on the current state of the Placement API split.
For some background, the nova placement API was removed from nova in train, and it's been split into its own project. It's mostly just a basic API charm. The tricky part is the migration of tables from the nova_api database to the placement database.
Test scenarios I've been testing with:
1) deploy nova-cc et al train, configure keystonev3, deploy instance
2) deploy nova-cc et al stein, configure keystonev3, deploy instance 1, deploy placement train, deploy instance 2, upgrade nova-cc to train, deploy instance 3
There is currently an issue with the second test scenario where instance 2 creation errors because nova-scheduler can't find a valid placement candidate (not sure of the exact error atm). However if I delete instance 1 before creating instance 2 it is created successfully. It feels like a DB related issue but I'm really not sure so I'll keep digging.