Moves all tasks run by the Celery worker into a discrete package/module
for easier installation. Also adjusts several parameters throughout to
accomplish this.
For whatever reason, a Celery worker on <5.2.x was not picking these up.
Move them back to the root of the module so they are properly picked up
on these older versions but still prevents calling the routing functions
during an API doc generation.
Avoids calling unworkable functions when generating API docs etc. by
isolating them into a Celery startup function called by Daemon.py.
Also update to Celery 4+ settings format.
Updates all the example provisioner scripts to use the new functions
exposed by the VMBuilder class as an illustration of how best to use
them.
Also adds a wrapper fail() handler to ensure the cleanup of the script,
as well as the global cleanup, are run on an exception.
Full UUIDs were obnoxiously long, so switch to using just the first
8-character section of a UUID instead. Keeps the list nice and short,
makes them easier to copy, and is just generally nicer.
Could this cause uniqueness problems? Perhaps, but I don't see that
happening nearly frequently enough to matter.
Move the create_vm and run_benchmark tasks to use the new Celery
subsystem, handlers, and wait command. Remove the obsolete, dedicated
API endpoints.
Standardize the CLI client and move the repeated handler code into a
separate common function.
By default, tasks will continue to run as they did, on the primary
coordinator's task runner. However this opens the possibility for
defining more tasks that will run on other nodes or coordinators.
Redis did not provide a distributed solution for the worker, which
precluded several important planned functions. So instead, move to using
Zookeeper + PostgreSQL as the broker and result backend respectively.
Should be a seamless drop-in change but for future uses requires the
database host to be the primary coordinator IP rather than localhost, so
that writes can occur to the database from non-primary hosts.
