Observability Libs
- Jon Seager
Channel | Revision | Published | Runs on |
---|---|---|---|
latest/edge | 50 | 11 Oct 2024 |
juju deploy observability-libs --channel edge
Deploy Kubernetes operators easily with Juju, the Universal Operator Lifecycle Manager. Need a Kubernetes cluster? Install MicroK8s to create a full CNCF-certified Kubernetes system in under 60 seconds.
Platform:
charms.observability_libs.v0.metrics_endpoint_discovery
-
- Last updated 20 Feb 2024
- Revision Library version 0.7
MetricsEndpointDiscovery Library.
This library provides functionality for discovering metrics endpoints exposed by applications deployed to a Kubernetes cluster.
It comprises:
- A custom event and event source for handling metrics endpoint changes.
- Logic to observe cluster events and emit the events as appropriate.
Using the Library
Handling Events
To ensure that your charm can react to changing metrics endpoint events, use the CharmEvents extension.
import json
from charms.observability_libs.v0.metrics_endpoint_discovery import
MetricsEndpointCharmEvents,
MetricsEndpointObserver
)
class MyCharm(CharmBase):
on = MetricsEndpointChangeCharmEvents()
def __init__(self, *args):
super().__init__(*args)
self._observer = MetricsEndpointObserver(self, {"app.kubernetes.io/name": ["grafana-k8s"]})
self.framework.observe(self.on.metrics_endpoint_change, self._on_endpoints_change)
def _on_endpoints_change(self, event):
self.unit.status = ActiveStatus(json.dumps(event.discovered))
Index
class MetricsEndpointChangeEvent
Description
A custom event for metrics endpoint changes. None
Methods
MetricsEndpointChangeEvent. __init__( self , handle )
MetricsEndpointChangeEvent. snapshot( self )
Description
Save the event payload data. None
MetricsEndpointChangeEvent. restore( self , snapshot )
Description
Restore the event payload data. None
MetricsEndpointChangeEvent. discovered( self )
Description
Return the payload of detected endpoint changes for this event. None
class MetricsEndpointChangeCharmEvents
A CharmEvents extension for metrics endpoint changes.
Description
Includes :class:MetricsEndpointChangeEvent
in those that can be handled.
class MetricsEndpointObserver
Observes changing metrics endpoints in the cluster.
Description
Observed endpoint changes cause :class"MetricsEndpointChangeEvent
to be emitted.
Methods
MetricsEndpointObserver. __init__( self , charm: CharmBase , labels )
Constructor for MetricsEndpointObserver.
Arguments
the charm that is instantiating the library.
dictionary of label/value to be observed for changing metrics endpoints.
MetricsEndpointObserver. start_observer( self )
Description
Start the metrics endpoint observer running in a new process. None
MetricsEndpointObserver. stop_observers( self )
Description
Stops all running instances of the observer. None
MetricsEndpointObserver. unit_tag( self )
Description
Juju-style tag identifying the unit being run by this charm. None
def write_payload(payload)
Description
Write the input event data to event payload file. None
def
dispatch(
run_cmd,
unit,
charm_dir
)
Description
Use the input juju-run command to dispatch a :class:MetricsEndpointChangeEvent
. None
def main()
Main watch and dispatch loop.
Description
Watch the input k8s service names. When changes are detected, write the observed data to the payload file, and dispatch the change event.