What: If BUILDKITE_PULL_REQUEST_REPO is empty string, default to DEFAULT_REPO
Why: BUILDKITE_PULL_REQUEST_REPO is set to an empty string per default, thus we're currently not detecting the buildkite repo correctly in branched builds.
Apparently, ray gets imported somewhere before running the client runner (maybe from an anyscale package). This means that we need to reload the ray package after installing a matching local ray wheel.
Additionally, job submission should also install a matching local ray to match with the job submission server.
Adds a unit-tested and restructured ray_release package for running release tests.
Relevant changes in behavior:
Per default, Buildkite will wait for the wheels of the current commit to be available. Alternatively, users can a) specify a different commit hash, b) a wheels URL (which we will also wait for to be available) or c) specify a branch (or user/branch combination), in which case the latest available wheels will be used (e.g. if master is passed, behavior matches old default behavior).
The main subpackages are:
Cluster manager: Creates cluster envs/computes, starts cluster, terminates cluster
Command runner: Runs commands, e.g. as client command or sdk command
File manager: Uploads/downloads files to/from session
Reporter: Reports results (e.g. to database)
Much of the code base is unit tested, but there are probably some pieces missing.
Example build (waited for wheels to be built): https://buildkite.com/ray-project/kf-dev/builds/51#_
Wheel build: https://buildkite.com/ray-project/ray-builders-branch/builds/6023