Removes the dependency of the monitoring subsystem from the node
keepalives, and runs them at a 60s interval to avoid excessive backups
if a plugin takes too long.
Adds its own logs and related items as required.
Finally adds a new required argument to the run() of plugins, the
coordinator state, which can be used by a plugin to determine actions
based on whether the node is a primary, secondary, or non-coordinator.
Ensure that all keepalive timeouts are set (prevent the queue.get()
actions from blocking forever) and set the thread timeouts to line up as
well. Everything here is thus limited to keepalive_interval seconds
(default 5s) to keep it uniform.
This branch commit refactors the pvcnoded component to better adhere to
good programming practices. The previous Daemon.py was a massive file
which contained almost 2000 lines of direct, root-level code which was
directly imported. Not only was this poor practice, but this resulted
in a nigh-unmaintainable file which was hard even for me to understand.
This refactoring splits a large section of the code from Daemon.py into
separate small modules and functions in the `util/` directory. This will
hopefully make most of the functionality easy to find and modify without
having to dig through a single large file.
Further the existing subcomponents have been moved to the `objects/`
directory which clearly separates them.
Finally, the Daemon.py code has mostly been moved into a function,
`entrypoint()`, which is then called from the `pvcnoded.py` stub.
An additional item is that most format strings have been replaced by
f-strings to make use of the Python 3.6 features in Daemon.py and the
utility files.
Joshua Boniface