this commit implements the bulk of `awx-manage run_dispatcher`, a new
command that binds to RabbitMQ via kombu and balances messages across
a pool of workers that are similar to celeryd workers in spirit.
Specifically, this includes:
- a new decorator, `awx.main.dispatch.task`, which can be used to
decorate functions or classes so that they can be designated as
"Tasks"
- support for fanout/broadcast tasks (at this point in time, only
`conf.Setting` memcached flushes use this functionality)
- support for job reaping
- support for success/failure hooks for job runs (i.e.,
`handle_work_success` and `handle_work_error`)
- support for auto scaling worker pool that scale processes up and down
on demand
- minimal support for RPC, such as status checks and pool recycle/reload
refactor existing handlers to be the related
"real" handler classes, which are swapped
out dynamically by external logger "proxy" handler class
real handler swapout only done on setting change
remove restart_local_services method
get rid of uWSGI fifo file
change TCP/UDP return type contract so that it mirrors
the request futures object
add details to socket error messages
In some systems, the tower service process may not have sufficient
permissions to communicate with the supervisorctl socket, in which
case an automated restart will not be possible.
