Prometheus operator and alerting¶

Configure the prometheus resource¶

Section	Explanation
spec.alerting	Configure the alertmanager endpoints to send the alerts

There are a lot of other prometheus and kubernetes settings we can configure (replicas, retention, persistent storage, resources,...)

Setup the alertmanager resource¶

This will deploy an alertmanager statefulset and its settings

metadata.namespace

pending

metadata.labels

pending

Alertmanager configuration¶

There are 3 ways to configure alertmanager

spec.configSecret

With this we can choose a Kubernetes secret that contains a native alertmanager configuration (global) in the alertmanager.yaml key.

kubectl create secret generic myalertmanagerconfig --from-file=alertmanager.yaml=myfile.yaml

And in the alertmanager resource

apiVersion: monitoring.coreos.com/v1
kind: Alertmanager
metadata:
  name: myalertmanager
spec:
  configSecret: myalertmanagerconfig

The default value is alertmanager-name_of-the_alertmanager_instance. If the alertmanager.yaml key does not exist or a secret is not defined, a default configuration will deployed dropping alert notifications.

spec.alertmanagerConfiguration

Experimental feature that takes precedence over the configSecret field as a global configuration. We can choose an alertmanagerconfig kubernetes resource.

apiVersion: monitoring.coreos.com/v1
kind: Alertmanager
metadata:
  name: myalertmanager
spec:
  alertmanagerConfiguration:
    name: myalertmanagerconfig

spec.alertmanagerConfigSelector

Choose what labels should have an alertmanagerconfig resource to be selected for to merge and configure Alertmanager with.

apiVersion: monitoring.coreos.com/v1
kind: Alertmanager
metadata:
  name: myalertmanager
spec:
  alertmanagerConfigSelector:
    matchLabels:
      mylabel: myvalue