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An additional item is that most format strings have been replaced by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.
Adds the ability to send node daemon logs to Zookeeper to facilitate a
command like "pvc node log", similar to "pvc vm log". Each node stores
its logs in a separate tree under "/logs" which can then be combined or
queried. By default, set by config, only 2000 lines are kept.
This reverts commit 65d14ccd92.
This was actually a bad idea. For inexplicable reasons, running these
Ceph commands manually (not even via Python, but in a normal shell)
takes 7 * two orders of magnitude longer than running them with the
Rados module, so long in fact that some basic commands like "ceph
health" would sometimes take longer than the 1 second timeout to
complete. The Rados commands would however take about 1ms instead.
Despite the occasional issues when monitors drop out, the Rados module
is clearly far superior to the shell commands for any moderately-loaded
Ceph cluster. We can look into solving timeouts another way (perhaps
with Processes instead of Threads) at a later time.
Rados module "ceph health":
b'{"checks":{},"status":"HEALTH_OK"}'
0.001204 (s)
b'{"checks":{},"status":"HEALTH_OK"}'
0.001258 (s)
Command "ceph health":
joshua@hv1.c.bonilan.net ~ $ time ceph health >/dev/null
real 0m0.772s
user 0m0.707s
sys 0m0.046s
joshua@hv1.c.bonilan.net ~ $ time ceph health >/dev/null
real 0m0.796s
user 0m0.728s
sys 0m0.054s
Using the Rados module was very problematic, specifically because it had
no sensible timeout parameters and thus would hang for many seconds.
This has poor implications since it blocks further keepalives.
Instead, remove the Rados usage entirely and go back completely to using
manual OS commands to gather this information. While this may cause PID
exhaustion more quickly it's worthwhile to avoid failure scenarios when
Ceph stats time out.
Closes#137
Ensures that the configuration of a VF is not overwritten in Zookeeper
on a node restart. The SRIOVVFInstance handlers were modified to start
with None values, so that the DataWatch statements will always trigger
updates to the live system interfaces on daemon startup, thus ensuring
that the config stored in Zookeeper is applied to the system on startup
(mostly relevant after a cold boot or if the API changes them during a
daemon restart).
Adds support for the node daemon managing SR-IOV PF and VF instances.
PFs are added to Zookeeper automatically based on the config at startup
during network configuration, and are otherwise completely static. PFs
are automatically removed from Zookeeper, along with all coresponding
VFs, should the PF phy device be removed from the configuration.
VFs are configured based on the (autocreated) VFs of each PF device,
added to Zookeeper, and then a new class instance, SRIOVVFInstance, is
used to watch them for configuration changes. This will enable the
runtime management of VF settings by the API. The set of keys ensures
that both configuration and details of the NIC can be tracked.
Most keys are self-explanatory, especially for PFs and the basic keys
for VFs. The configuration tree is also self-explanatory, being based
entirely on the options available in the `ip link set {dev} vf` command.
Two additional keys are also present: `used` and `used_by`, which will
be able to track the (boolean) state of usage, as well as the VM that
uses a given VIF. Since the VM side implementation will support both
macvtap and direct "hostdev" assignments, this will ensure that this
state can be tracked on both the VF and the VM side.
Adds configuration values for enabled flag and SR-IOV devices to the
configuration and sets up the initial SR-IOV configuration on daemon
startup (inserting the module, configuring the VF count, etc.).
Instead of exiting and trusting systemd to restart us, instead leverage
the os.execv() call to reload the process in the current PID context.
Also improves the log messages so it's very clear what's going on.
A hot reload isn't possible due to DataWatch and ChildrenWatch
constructs, so we instead need to terminate the daemon to "apply" the
schema update. Thus we use exit code 150 (Application defined in LSB)
and reorder some of the elements of the schema validation to ensure
things happen in the right order.
Joshua Boniface