75abdb4148
We are phasing out use of ironic-lib, and as such are removing the metrics module from it. However, due to it's requirement of having a statsd instance on the same subnet as the agent and there being no support for prometheus exporting of metrics from IPA, these metrics are no longer valuable (in the agent). We are vendoring the module for the deprecation in order to facilitate its removal from ironic-lib. Change-Id: Ie50e078bc3f78d65cfa53680dc4116d1119ce155
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Emitting metrics from Ironic-Python-Agent (IPA)
Warning
IPA metrics are deprecated and scheduled for removal at or after the 2026.1 OpenStack release cycle.
This document describes how to emit metrics from IPA, including timers and counters in code to directly emitting hardware metrics from a custom HardwareManager.
Overview
IPA uses a vendored version of the metrics implementation originally from ironic-lib, with a few caveats due to the dynamic configuration done at lookup time. You cannot cache the metrics instance as the MetricsLogger returned will change after lookup if configs different than the default setting have been used. This also means that the method decorator cannot be used in IPA.
Using a context manager
Using the context manager is the recommended way for sending metrics that time or count sections of code. However, given that you cannot cache the MetricsLogger, you have to explicitly call get_metrics_logger() from every time. For example:
from ironic_python_agent.metrics_lib import metrics_utils
def my_method():
with metrics_utils.get_metrics_logger(__name__).timer('my_method'):
return _do_work()As a note, these metric collectors do work for custom HardwareManagers as well. However, you may want to metric the portions of a method that determine compatibility separate from portions of a method that actually do work, in order to assure the metrics are relevant and useful on all hardware.
Explicitly sending metrics
A feature that may be particularly helpful for deployers writing custom HardwareManagers is the ability to explicitly send metrics. For instance, you could add a cleaning step which would retrieve metrics about a device and ship them using the provided metrics library. For example:
from ironic_python_agent.metrics_lib import metrics_utils
def my_cleaning_step():
for name, value in _get_smart_data():
metrics_utils.get_metrics_logger(__name__).send_gauge(name, value)