Provide an ad-hoc maintenance lock for clustered repositories
Summary: Ref T13614. Provide "bin/repository lock" to temporarily lock repositories for manual maintenance.
- Read instructions.
- Used bin/repository lock according to the instructions.
- Saw Storage tab in Diffusion report lock held during maintenance, released after it completes.
- Saw "maintenance" push log generated and repository version bump.
- Tried to lock some invalid repositories.
Maniphest Tasks: T13614
Differential Revision: https://secure.phabricator.com/D21671