Ensures that information like the FSIDs and the OSD LVM volume are
stored in Zookeeper at creation time and updated at daemon start time
(to ensure the data is populated at least once, or if the /dev/sdX
path changes).
This will allow safer operation of OSD removals and the potential
implementation of re-activation after node replacements.
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An additional item is that most format strings have been replaced by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.
We need to do a bit more finagling with the logger on termination to
ensure that all messages are written and the queue drained before
actually terminating.
Joshua Boniface