Simple distributed locks using lockgate.
The server holds the locks. It can be deployed to Heroku with git push.
The client is a command-line application that can request a lock and renew a lock.
Use deploylock-client acquire -n <lockname> https://deploylock-server/ to acquire a lock.
It will block until the lock is successfully retrieved. Clients waiting to
acquire the lock are placed in a FIFO queue.
Upon successfully acquiring the lock, the lock's UUID will be written to stdout
and deploylock-client will exit.
Keep the lock by running deploylock-client renew -n <lockname -l <uuid> https://deploylock-server/. This can be placed in the background to run other
commands that require the lock. Kill deploylock-client renew to release the
lock.
Deploylock was built to help coordinate long-running builds against Salesforce orgs. Due to defects in the Metadata API, it's sometimes necessary to perform multiple deployments sequentially. Deploylock can be used to prevent deployments from independent builds from getting intertwined by using an external lock on the org.
Shared locks aren't supported. Lockgate supports shared locks, but a use case for deploylock hasn't been identified yet.