monitoring-configuring-the-cluster-monitoring-stack.adoc

Configuring the cluster monitoring stack

You can configure the Prometheus Cluster Monitoring stack using ConfigMaps. ConfigMaps configure the Cluster Monitoring Operator, which in turn configures components of the stack.

Prerequisites

• Make sure you have the cluster-monitoring-config ConfigMap object with the data/config.yaml section.

Procedure

1. Start editing the cluster-monitoring-config ConfigMap:

   $ oc -n openshift-monitoring edit configmap cluster-monitoring-config

2. Put your configuration under data/config.yaml as key-value pair <component_name>: <component_configuration>:

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: cluster-monitoring-config
     namespace: openshift-monitoring
   data:
     config.yaml: |
       <component>:
         <configuration_for_the_component>

   Substitute <component> and <configuration_for_the_component> accordingly.

   For example, create this ConfigMap to configure a Persistent Volume Claim (PVC) for Prometheus:

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: cluster-monitoring-config
     namespace: openshift-monitoring
   data:
     config.yaml: |
       prometheusK8s:
         volumeClaimTemplate:
          spec:
            storageClassName: fast
            volumeMode: Filesystem
            resources:
              requests:
                storage: 40Gi

   Here, prometheusK8s defines the Prometheus component and the following lines define its configuration.

3. Save the file to apply the changes. The pods affected by the new configuration are restarted automatically.