Cluster logging is configurable using a Cluster Logging Custom Resource (CR) deployed in the openshift-logging project.

The Cluster Logging Operator watches for changes to Cluster Logging CRs, creates any missing logging components, and adjusts the logging deployment accordingly.

The Cluster Logging CR is based on the Cluster Logging Custom Resource Definition (CRD), which defines a complete cluster logging deployment and includes all the components of the logging stack to collect, store and visualize logs.

Sample Cluster Logging Custom Resource (CR)
apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  creationTimestamp: '2019-03-20T18:07:02Z'
  generation: 1
  name: instance
  namespace: openshift-logging
spec:
  collection:
    logs:
      fluentd:
        resources: null
      type: fluentd
  logStore:
    elasticsearch:
      nodeCount: 3
      redundancyPolicy: SingleRedundancy
      resources:
        limits:
          cpu:
          memory:
        requests:
          cpu:
          memory:
      storage: {}
    type: elasticsearch
  managementState: Managed
  visualization:
    kibana:
      proxy:
        resources: null
      replicas: 1
      resources: null
    type: kibana

You can configure the following for cluster logging:

  • You can place cluster logging into an unmanaged state that allows an administrator to assume full control of individual component configurations and upgrades.

  • You can overwrite the image for each cluster logging component by modifying the appropriate environment variable in the cluster-logging-operator Deployment.

  • You can specify specific nodes for the logging components using node selectors.

The logging routes are managed by the Cluster Logging Operator and cannot be modified by the user.