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Configuring the monitoring stack | Monitoring | OpenShift Container Platform 4.10
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Configuring the monitoring stack

The OpenShift Container Platform 4 installation program provides only a low number of configuration options before installation. Configuring most OpenShift Container Platform framework components, including the cluster monitoring stack, happens post-installation.

This section explains what configuration is supported, shows how to configure the monitoring stack, and demonstrates several common configuration scenarios.

Prerequisites

  • The monitoring stack imposes additional resource requirements. Consult the computing resources recommendations in Scaling the Cluster Monitoring Operator and verify that you have sufficient resources.

Maintenance and support for monitoring

The supported way of configuring OpenShift Container Platform Monitoring is by configuring it using the options described in this document. Do not use other configurations, as they are unsupported. Configuration paradigms might change across Prometheus releases, and such cases can only be handled gracefully if all configuration possibilities are controlled. If you use configurations other than those described in this section, your changes will disappear because the cluster-monitoring-operator reconciles any differences. The Operator resets everything to the defined state by default and by design.

Support considerations for monitoring

The following modifications are explicitly not supported:

  • Creating additional ServiceMonitor, PodMonitor, and PrometheusRule objects in the openshift-* and kube-* projects.

  • Modifying any resources or objects deployed in the openshift-monitoring or openshift-user-workload-monitoring projects. The resources created by the OpenShift Container Platform monitoring stack are not meant to be used by any other resources, as there are no guarantees about their backward compatibility.

    The Alertmanager configuration is deployed as a secret resource in the openshift-monitoring project. To configure additional routes for Alertmanager, you need to decode, modify, and then encode that secret. This procedure is a supported exception to the preceding statement.

  • Modifying resources of the stack. The OpenShift Container Platform monitoring stack ensures its resources are always in the state it expects them to be. If they are modified, the stack will reset them.

  • Deploying user-defined workloads to openshift-*, and kube-* projects. These projects are reserved for Red Hat provided components and they should not be used for user-defined workloads.

  • Modifying the monitoring stack Grafana instance.

  • Installing custom Prometheus instances on OpenShift Container Platform. A custom instance is a Prometheus custom resource (CR) managed by the Prometheus Operator.

  • Enabling symptom based monitoring by using the Probe custom resource definition (CRD) in Prometheus Operator.

  • Modifying Alertmanager configurations by using the AlertmanagerConfig CRD in Prometheus Operator.

Backward compatibility for metrics, recording rules, or alerting rules is not guaranteed.

Support policy for monitoring Operators

Monitoring Operators ensure that OpenShift Container Platform monitoring resources function as designed and tested. If Cluster Version Operator (CVO) control of an Operator is overridden, the Operator does not respond to configuration changes, reconcile the intended state of cluster objects, or receive updates.

While overriding CVO control for an Operator can be helpful during debugging, this is unsupported and the cluster administrator assumes full control of the individual component configurations and upgrades.

Overriding the Cluster Version Operator

The spec.overrides parameter can be added to the configuration for the CVO to allow administrators to provide a list of overrides to the behavior of the CVO for a component. Setting the spec.overrides[].unmanaged parameter to true for a component blocks cluster upgrades and alerts the administrator after a CVO override has been set:

Disabling ownership via cluster version overrides prevents upgrades. Please remove overrides before continuing.

Setting a CVO override puts the entire cluster in an unsupported state and prevents the monitoring stack from being reconciled to its intended state. This impacts the reliability features built into Operators and prevents updates from being received. Reported issues must be reproduced after removing any overrides for support to proceed.

Preparing to configure the monitoring stack

You can configure the monitoring stack by creating and updating monitoring config maps.

Creating a cluster monitoring config map

To configure core OpenShift Container Platform monitoring components, you must create the cluster-monitoring-config configmap object in the openshift-monitoring project.

When you save your changes to the cluster-monitoring-config configmap object, some or all of the pods in the openshift-monitoring project might be redeployed. It can sometimes take a while for these components to redeploy.
Prerequisites

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Check whether the cluster-monitoring-config configmap object exists:

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

  2. If the configmap object does not exist:

    1. Create the following YAML manifest. In this example the file is called cluster-monitoring-config.yaml:

      apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |

    2. Apply the configuration to create the configmap object:

      $ oc apply -f cluster-monitoring-config.yaml

Creating a user-defined workload monitoring config map

To configure the components that monitor user-defined projects, you must create the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project.

When you save your changes to the user-workload-monitoring-config configmap object, some or all of the pods in the openshift-user-workload-monitoring project might be redeployed. It can sometimes take a while for these components to redeploy. You can create and configure the config map before you first enable monitoring for user-defined projects, to prevent having to redeploy the pods often.
Prerequisites

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Check whether the user-workload-monitoring-config configmap object exists:

    $ oc -n openshift-user-workload-monitoring get configmap user-workload-monitoring-config

  2. If the user-workload-monitoring-config configmap object does not exist:

    1. Create the following YAML manifest. In this example the file is called user-workload-monitoring-config.yaml:

      apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |

    2. Apply the configuration to create the configmap object:

      $ oc apply -f user-workload-monitoring-config.yaml

      Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.
Additional resources

Configuring the monitoring stack

In OpenShift Container Platform 4.10, you can configure the monitoring stack using the cluster-monitoring-config or user-workload-monitoring-config configmap objects. Config maps configure the Cluster Monitoring Operator (CMO), which in turn configures the components of the stack.

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object.

    • To configure core OpenShift Container Platform monitoring components:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Add your configuration under data/config.yaml as a 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.

        The following example configmap object configures a persistent volume claim (PVC) for Prometheus. This relates to the Prometheus instance that monitors core OpenShift Container Platform components only:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s: (1)
      volumeClaimTemplate:
        spec:
          storageClassName: fast
          volumeMode: Filesystem
          resources:
            requests:
              storage: 40Gi
        1 Defines the Prometheus component and the subsequent lines define its configuration.

    • To configure components that monitor user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

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

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>:
      <configuration_for_the_component>

        Substitute <component> and <configuration_for_the_component> accordingly.

        The following example configmap object configures a data retention period and minimum container resource requests for Prometheus. This relates to the Prometheus instance that monitors user-defined projects only:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus: (1)
      retention: 24h (2)
      resources:
        requests:
          cpu: 200m (3)
          memory: 2Gi (4)
        1 Defines the Prometheus component and the subsequent lines define its configuration.
        2 Configures a twenty-four hour data retention period for the Prometheus instance that monitors user-defined projects.
        3 Defines a minimum resource request of 200 millicores for the Prometheus container.
        4 Defines a minimum pod resource request of 2 GiB of memory for the Prometheus container.

        The Prometheus config map component is called prometheusK8s in the cluster-monitoring-config configmap object and prometheus in the user-workload-monitoring-config configmap object.

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

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.
Additional resources

Configurable monitoring components

This table shows the monitoring components you can configure and the keys used to specify the components in the cluster-monitoring-config and user-workload-monitoring-config configmap objects:

Table 1. Configurable monitoring components
Component cluster-monitoring-config config map key user-workload-monitoring-config config map key

Prometheus Operator

prometheusOperator

prometheusOperator

Prometheus

prometheusK8s

prometheus

Alertmanager

alertmanagerMain

kube-state-metrics

kubeStateMetrics

openshift-state-metrics

openshiftStateMetrics

Grafana

grafana

Telemeter Client

telemeterClient

Prometheus Adapter

k8sPrometheusAdapter

Thanos Querier

thanosQuerier

Thanos Ruler

thanosRuler

The Prometheus key is called prometheusK8s in the cluster-monitoring-config configmap object and prometheus in the user-workload-monitoring-config configmap object.

Using node selectors to move monitoring components

By using the nodeSelector constraint with labeled nodes, you can move any of the monitoring stack components to specific nodes. By doing so, you can control the placement and distribution of the monitoring components across a cluster.

By controlling placement and distribution of monitoring components, you can optimize system resource use, improve performance, and segregate workloads based on specific requirements or policies.

How node selectors work with other constraints

If you move monitoring components by using node selector constraints, be aware that other constraints to control pod scheduling might exist for a cluster:

  • Topology spread constraints might be in place to control pod placement.

  • Hard anti-affinity rules are in place for Prometheus, Thanos Querier, Alertmanager, and other monitoring components to ensure that multiple pods for these components are always spread across different nodes and are therefore always highly available.

When scheduling pods onto nodes, the pod scheduler tries to satisfy all existing constraints when determining pod placement. That is, all constraints compound when the pod scheduler determines which pods will be placed on which nodes.

Therefore, if you configure a node selector constraint but existing constraints cannot all be satisfied, the pod scheduler cannot match all constraints and will not schedule a pod for placement onto a node.

To maintain resilience and high availability for monitoring components, ensure that enough nodes are available and match all constraints when you configure a node selector constraint to move a component.

Additional resources

Moving monitoring components to different nodes

To specify the nodes in your cluster on which monitoring stack components will run, configure the nodeSelector constraint in the component’s configmap object to match labels assigned to the nodes.

You cannot add a node selector constraint directly to an existing scheduled pod.
Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. If you have not done so yet, add a label to the nodes on which you want to run the monitoring components:

    $ oc label nodes <node-name> <node-label>

  2. Edit the configmap object:

    • To move a component that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Specify the node labels for the nodeSelector constraint for the component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    <component>: (1)
      nodeSelector:
        <node-label-1> (2)
        <node-label-2> (3)
        <...>
        1 Substitute <component> with the appropriate monitoring stack component name.
        2 Substitute <node-label-1> with the label you added to the node.
        3 Optional: Specify additional labels. If you specify additional labels, the pods for the component are only scheduled on the nodes that contain all of the specified labels.

        If monitoring components remain in a Pending state after configuring the nodeSelector constraint, check the pod events for errors relating to taints and tolerations.

    • To move a component that monitors user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Specify the node labels for the nodeSelector constraint for the component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>: (1)
      nodeSelector:
        <node-label-1> (2)
        <node-label-2> (3)
        <...>
        1 Substitute <component> with the appropriate monitoring stack component name.
        2 Substitute <node-label-1> with the label you added to the node.
        3 Optional: Specify additional labels. If you specify additional labels, the pods for the component are only scheduled on the nodes that contain all of the specified labels.

        If monitoring components remain in a Pending state after configuring the nodeSelector constraint, check the pod events for errors relating to taints and tolerations.

  3. Save the file to apply the changes. The components specified in the new configuration are moved to the new nodes automatically.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When you save changes to a monitoring config map, the pods and other resources in the project might be redeployed. The running monitoring processes in that project might also restart.
Additional resources

Assigning tolerations to monitoring components

You can assign tolerations to any of the monitoring stack components to enable moving them to tainted nodes.

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object:

    • To assign tolerations to a component that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Specify tolerations for the component:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    <component>:
      tolerations:
        <toleration_specification>

        Substitute <component> and <toleration_specification> accordingly.

        For example, oc adm taint nodes node1 key1=value1:NoSchedule adds a taint to node1 with the key key1 and the value value1. This prevents monitoring components from deploying pods on node1 unless a toleration is configured for that taint. The following example configures the alertmanagerMain component to tolerate the example taint:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    alertmanagerMain:
      tolerations:
      - key: "key1"
        operator: "Equal"
        value: "value1"
        effect: "NoSchedule"

    • To assign tolerations to a component that monitors user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Specify tolerations for the component:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>:
      tolerations:
        <toleration_specification>

        Substitute <component> and <toleration_specification> accordingly.

        For example, oc adm taint nodes node1 key1=value1:NoSchedule adds a taint to node1 with the key key1 and the value value1. This prevents monitoring components from deploying pods on node1 unless a toleration is configured for that taint. The following example configures the thanosRuler component to tolerate the example taint:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    thanosRuler:
      tolerations:
      - key: "key1"
        operator: "Equal"
        value: "value1"
        effect: "NoSchedule"

  2. Save the file to apply the changes. The new component placement configuration is applied automatically.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.
Additional resources

Configuring a dedicated service monitor

You can configure OpenShift Container Platform core platform monitoring to use dedicated service monitors to collect metrics for the resource metrics pipeline.

When enabled, a dedicated service monitor exposes two additional metrics from the kubelet endpoint and sets the value of the honorTimestamps field to true.

By enabling a dedicated service monitor, you can improve the consistency of Prometheus Adapter-based CPU usage measurements used by, for example, the oc adm top pod command or the Horizontal Pod Autoscaler.

Enabling a dedicated service monitor

You can configure core platform monitoring to use a dedicated service monitor by configuring the dedicatedServiceMonitors key in the cluster-monitoring-config configmap object in the openshift-monitoring namespace.

Prerequisites

  • You have installed the OpenShift CLI (oc).

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have created the cluster-monitoring-config configmap object.

Procedure

  1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring namespace:

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

  2. Add an enabled: true key-value pair as shown in the following sample:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    k8sPrometheusAdapter:
      dedicatedServiceMonitors:
        enabled: true (1)
    1 Set the value of the enabled field to true to deploy a dedicated service monitor that exposes the kubelet /metrics/resource endpoint.

  3. Save the file to apply the changes automatically.

    When you save changes to a cluster-monitoring-config config map, the pods and other resources in the openshift-monitoring project might be redeployed. The running monitoring processes in that project might also restart.

Configuring persistent storage

Running cluster monitoring with persistent storage means that your metrics are stored to a persistent volume (PV) and can survive a pod being restarted or recreated. This is ideal if you require your metrics or alerting data to be guarded from data loss. For production environments, it is highly recommended to configure persistent storage. Because of the high IO demands, it is advantageous to use local storage.

See Recommended configurable storage technology.

Persistent storage prerequisites

  • Dedicate sufficient local persistent storage to ensure that the disk does not become full. How much storage you need depends on the number of pods. For information on system requirements for persistent storage, see Prometheus database storage requirements.

  • Verify that you have a persistent volume (PV) ready to be claimed by the persistent volume claim (PVC), one PV for each replica. Because Prometheus and Alertmanager both have two replicas, you need four PVs to support the entire monitoring stack. The PVs are available from the Local Storage Operator, but not if you have enabled dynamically provisioned storage.

  • Use Filesystem as the storage type value for the volumeMode parameter when you configure the persistent volume.

  • Configure local persistent storage.

    If you use a local volume for persistent storage, do not use a raw block volume, which is described with volumeMode: Block in the LocalVolume object. Prometheus cannot use raw block volumes.

    Prometheus does not support file systems that are not POSIX compliant. For example, some NFS file system implementations are not POSIX compliant. If you want to use an NFS file system for storage, verify with the vendor that their NFS implementation is fully POSIX compliant.

Configuring a local persistent volume claim

For monitoring components to use a persistent volume (PV), you must configure a persistent volume claim (PVC).

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object:

    • To configure a PVC for a component that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Add your PVC configuration for the component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    <component>:
      volumeClaimTemplate:
        spec:
          storageClassName: <storage_class>
          resources:
            requests:
              storage: <amount_of_storage>

        See the Kubernetes documentation on PersistentVolumeClaims for information on how to specify volumeClaimTemplate.

        The following example configures a PVC that claims local persistent storage for the Prometheus instance that monitors core OpenShift Container Platform components:

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

        In the above example, the storage class created by the Local Storage Operator is called local-storage.

        The following example configures a PVC that claims local persistent storage for Alertmanager:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    alertmanagerMain:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 10Gi

    • To configure a PVC for a component that monitors user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Add your PVC configuration for the component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>:
      volumeClaimTemplate:
        spec:
          storageClassName: <storage_class>
          resources:
            requests:
              storage: <amount_of_storage>

        See the Kubernetes documentation on PersistentVolumeClaims for information on how to specify volumeClaimTemplate.

        The following example configures a PVC that claims local persistent storage for the Prometheus instance that monitors user-defined projects:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 40Gi

        In the above example, the storage class created by the Local Storage Operator is called local-storage.

        The following example configures a PVC that claims local persistent storage for Thanos Ruler:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    thanosRuler:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 10Gi

        Storage requirements for the thanosRuler component depend on the number of rules that are evaluated and how many samples each rule generates.

  2. Save the file to apply the changes. The pods affected by the new configuration are restarted automatically and the new storage configuration is applied.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.

Resizing a persistent storage volume

OpenShift Container Platform does not support resizing an existing persistent storage volume used by StatefulSet resources, even if the underlying StorageClass resource used supports persistent volume sizing. Therefore, even if you update the storage field for an existing persistent volume claim (PVC) with a larger size, this setting will not be propagated to the associated persistent volume (PV).

However, resizing a PV is still possible by using a manual process. If you want to resize a PV for a monitoring component such as Prometheus, Thanos Ruler, or Alertmanager, you can update the appropriate config map in which the component is configured. Then, patch the PVC, and delete and orphan the pods. Orphaning the pods recreates the StatefulSet resource immediately and automatically updates the size of the volumes mounted in the pods with the new PVC settings. No service disruption occurs during this process.

Prerequisites

  • You have installed the OpenShift CLI (oc).

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

    • You have configured at least one PVC for core OpenShift Container Platform monitoring components.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

    • You have configured at least one PVC for components that monitor user-defined projects.

Procedure

  1. Edit the configmap object:

    • To resize a PVC for a component that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Add a new storage size for the PVC configuration for the component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    <component>: (1)
      volumeClaimTemplate:
        spec:
          storageClassName: <storage_class> (2)
          resources:
            requests:
              storage: <amount_of_storage> (3)
        1 Specify the core monitoring component.
        2 Specify the storage class.
        3 Specify the new size for the storage volume.

        The following example configures a PVC that sets the local persistent storage to 100 gigabytes for the Prometheus instance that monitors core OpenShift Container Platform components:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 100Gi

        The following example configures a PVC that sets the local persistent storage for Alertmanager to 40 gigabytes:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    alertmanagerMain:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 40Gi

    • To resize a PVC for a component that monitors user-defined projects:

      You can resize the volumes for the Thanos Ruler and Prometheus instances that monitor user-defined projects.

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Update the PVC configuration for the monitoring component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>: (1)
      volumeClaimTemplate:
        spec:
          storageClassName: <storage_class> (2)
          resources:
            requests:
              storage: <amount_of_storage> (3)
        1 Specify the core monitoring component.
        2 Specify the storage class.
        3 Specify the new size for the storage volume.

        The following example configures the PVC size to 100 gigabytes for the Prometheus instance that monitors user-defined projects:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 100Gi

        The following example sets the PVC size to 20 gigabytes for Thanos Ruler:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    thanosRuler:
      volumeClaimTemplate:
        spec:
          storageClassName: local-storage
          resources:
            requests:
              storage: 20Gi

        Storage requirements for the thanosRuler component depend on the number of rules that are evaluated and how many samples each rule generates.

  2. Save the file to apply the changes. The pods affected by the new configuration restart automatically.

    When you save changes to a monitoring config map, the pods and other resources in the related project might be redeployed. The monitoring processes running in that project might also be restarted.

  3. Manually patch every PVC with the updated storage request. The following example resizes the storage size for the Prometheus component in the openshift-monitoring namespace to 100Gi:

    $ for p in $(oc -n openshift-monitoring get pvc -l app.kubernetes.io/name=prometheus -o jsonpath='{range .items[*]}{.metadata.name} {end}'); do \
  oc -n openshift-monitoring patch pvc/${p} --patch '{"spec": {"resources": {"requests": {"storage":"100Gi"}}}}'; \
  done

  4. Delete the underlying StatefulSet with the --cascade=orphan parameter:

    $ oc delete statefulset -l app.kubernetes.io/name=prometheus --cascade=orphan

Modifying the retention time for Prometheus metrics data

By default, the OpenShift Container Platform monitoring stack configures the retention time for Prometheus data to be 15 days. You can modify the retention time to change how soon the data is deleted.

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object:

    • To modify the retention time for the Prometheus instance that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Add your retention time configuration under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      retention: <time_specification>

        Substitute <time_specification> with a number directly followed by ms (milliseconds), s (seconds), m (minutes), h (hours), d (days), w (weeks), or y (years).

        The following example sets the retention time to 24 hours for the Prometheus instance that monitors core OpenShift Container Platform components:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      retention: 24h

    • To modify the retention time for the Prometheus instance that monitors user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Add your retention time configuration under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      retention: <time_specification>

        Substitute <time_specification> with a number directly followed by ms (milliseconds), s (seconds), m (minutes), h (hours), d (days), w (weeks), or y (years).

        The following example sets the retention time to 24 hours for the Prometheus instance that monitors user-defined projects:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      retention: 24h

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

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.

Modifying the retention time for Thanos Ruler metrics data

By default, for user-defined projects, Thanos Ruler automatically retains metrics data for 24 hours. You can modify the retention time to change how long this data is retained by specifying a time value in the user-workload-monitoring-config config map in the openshift-user-workload-monitoring namespace.

Prerequisites

  • You have installed the OpenShift CLI (oc).

  • A cluster administrator has enabled monitoring for user-defined projects.

  • You have access to the cluster as a user with the cluster-admin cluster role or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

  • You have created the user-workload-monitoring-config configmap object.

Saving changes to a monitoring config map might restart monitoring processes and redeploy the pods and other resources in the related project. The running monitoring processes in that project might also restart.
Procedure

  1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

    $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

  2. Add the retention time configuration under data/config.yaml:

    apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    thanosRuler:
      retention: <time_specification> (1)
    1 Specify the retention time in the following format: a number directly followed by ms (milliseconds), s (seconds), m (minutes), h (hours), d (days), w (weeks), or y (years). You can also combine time values for specific times, such as 1h30m15s. The default is 24h.

    The following example sets the retention time to 10 days for Thanos Ruler data:

    apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    thanosRuler:
      retention: 10d

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

Additional resources

Configuring remote write storage

You can configure remote write storage to enable Prometheus to send ingested metrics to remote systems for long-term storage. Doing so has no impact on how or for how long Prometheus stores metrics.

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

  • You have set up a remote write compatible endpoint (such as Thanos) and know the endpoint URL. See the Prometheus remote endpoints and storage documentation for information about endpoints that are compatible with the remote write feature.

  • You have set up authentication credentials for the remote write endpoint.

    To reduce security risks, avoid sending metrics to an endpoint via unencrypted HTTP or without using authentication.
Procedure

  1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

  2. Add a remoteWrite: section under data/config.yaml/prometheusK8s.

  3. Add an endpoint URL and authentication credentials in this section:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        <endpoint_authentication_credentials>

    For endpoint_authentication_credentials substitute the credentials for the endpoint. Currently supported authentication methods are basic authentication (basicAuth) and client TLS (tlsConfig) authentication.

    • The following example configures basic authentication:

      basicAuth:
  username:
    <usernameSecret>
  password:
    <passwordSecret>

      Substitute <usernameSecret> and <passwordSecret> accordingly.

      The following sample shows basic authentication configured with remoteWriteAuth for the name values and user and password for the key values. These values contain the endpoint authentication credentials:

      apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        basicAuth:
          username:
            name: remoteWriteAuth
            key: user
          password:
            name: remoteWriteAuth
            key: password

    • The following example configures client TLS authentication:

      tlsConfig:
  ca:
    <caSecret>
  cert:
    <certSecret>
  keySecret:
    <keySecret>

      Substitute <caSecret>, <certSecret>, and <keySecret> accordingly.

      The following sample shows a TLS authentication configuration using selfsigned-mtls-bundle for the name values and ca.crt for the ca key value, client.crt for the cert key value, and client.key for the keySecret key value:

      apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        tlsConfig:
          ca:
            secret:
              name: selfsigned-mtls-bundle
              key: ca.crt
          cert:
            secret:
              name: selfsigned-mtls-bundle
              key: client.crt
          keySecret:
            name: selfsigned-mtls-bundle
            key: client.key

  4. Add write relabel configuration values after the authentication credentials:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        <endpoint_authentication_credentials>
        <write_relabel_configs>

    For <write_relabel_configs> substitute a list of write relabel configurations for metrics that you want to send to the remote endpoint.

    The following sample shows how to forward a single metric called my_metric:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        writeRelabelConfigs:
        - sourceLabels: [__name__]
          regex: 'my_metric'
          action: keep

    See the Prometheus relabel_config documentation for information about write relabel configuration options.

  5. If required, configure remote write for the Prometheus instance that monitors user-defined projects by changing the name and namespace metadata values as follows:

    apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      remoteWrite:
      - url: "https://remote-write.endpoint"
        <endpoint_authentication_credentials>
        <write_relabel_configs>

    The Prometheus config map component is called prometheusK8s in the cluster-monitoring-config configmap object and prometheus in the user-workload-monitoring-config configmap object.

  6. Save the file to apply the changes to the configmap object. The pods affected by the new configuration restart automatically.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    Saving changes to a monitoring configmap object might redeploy the pods and other resources in the related project. Saving changes might also restart the running monitoring processes in that project.
Additional resources

Controlling the impact of unbound metrics attributes in user-defined projects

Developers can create labels to define attributes for metrics in the form of key-value pairs. The number of potential key-value pairs corresponds to the number of possible values for an attribute. An attribute that has an unlimited number of potential values is called an unbound attribute. For example, a customer_id attribute is unbound because it has an infinite number of possible values.

Every assigned key-value pair has a unique time series. The use of many unbound attributes in labels can result in an exponential increase in the number of time series created. This can impact Prometheus performance and can consume a lot of disk space.

Cluster administrators can use the following measures to control the impact of unbound metrics attributes in user-defined projects:

  • Limit the number of samples that can be accepted per target scrape in user-defined projects

  • Create alerts that fire when a scrape sample threshold is reached or when the target cannot be scraped

Limiting scrape samples can help prevent the issues caused by adding many unbound attributes to labels. Developers can also prevent the underlying cause by limiting the number of unbound attributes that they define for metrics. Using attributes that are bound to a limited set of possible values reduces the number of potential key-value pair combinations.

Setting a scrape sample limit for user-defined projects

You can limit the number of samples that can be accepted per target scrape in user-defined projects.

If you set a sample limit, no further sample data is ingested for that target scrape after the limit is reached.
Prerequisites

  • You have access to the cluster as a user with the cluster-admin role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

  • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

    $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

  2. Add the enforcedSampleLimit configuration to data/config.yaml to limit the number of samples that can be accepted per target scrape in user-defined projects:

    apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      enforcedSampleLimit: 50000 (1)
    1 A value is required if this parameter is specified. This enforcedSampleLimit example limits the number of samples that can be accepted per target scrape in user-defined projects to 50,000.

  3. Save the file to apply the changes. The limit is applied automatically.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to the user-workload-monitoring-config configmap object, the pods and other resources in the openshift-user-workload-monitoring project might be redeployed. The running monitoring processes in that project might also be restarted.

Creating scrape sample alerts

You can create alerts that notify you when:

  • The target cannot be scraped or is not available for the specified for duration

  • A scrape sample threshold is reached or is exceeded for the specified for duration

Prerequisites

  • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

  • You have enabled monitoring for user-defined projects.

  • You have created the user-workload-monitoring-config configmap object.

  • You have limited the number of samples that can be accepted per target scrape in user-defined projects, by using enforcedSampleLimit.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Create a YAML file with alerts that inform you when the targets are down and when the enforced sample limit is approaching. The file in this example is called monitoring-stack-alerts.yaml:

    apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  labels:
    prometheus: k8s
    role: alert-rules
  name: monitoring-stack-alerts (1)
  namespace: ns1 (2)
spec:
  groups:
  - name: general.rules
    rules:
    - alert: TargetDown (3)
      annotations:
        message: '{{ printf "%.4g" $value }}% of the {{ $labels.job }}/{{ $labels.service
          }} targets in {{ $labels.namespace }} namespace are down.' (4)
      expr: 100 * (count(up == 0) BY (job, namespace, service) / count(up) BY (job,
        namespace, service)) > 10
      for: 10m (5)
      labels:
        severity: warning (6)
    - alert: ApproachingEnforcedSamplesLimit (7)
      annotations:
        message: '{{ $labels.container }} container of the {{ $labels.pod }} pod in the {{ $labels.namespace }} namespace consumes {{ $value | humanizePercentage }} of the samples limit budget.' (8)
      expr: scrape_samples_scraped/50000 > 0.8 (9)
      for: 10m (10)
      labels:
        severity: warning (11)
    1 Defines the name of the alerting rule.
    2 Specifies the user-defined project where the alerting rule will be deployed.
    3 The TargetDown alert will fire if the target cannot be scraped or is not available for the for duration.
    4 The message that will be output when the TargetDown alert fires.
    5 The conditions for the TargetDown alert must be true for this duration before the alert is fired.
    6 Defines the severity for the TargetDown alert.
    7 The ApproachingEnforcedSamplesLimit alert will fire when the defined scrape sample threshold is reached or exceeded for the specified for duration.
    8 The message that will be output when the ApproachingEnforcedSamplesLimit alert fires.
    9 The threshold for the ApproachingEnforcedSamplesLimit alert. In this example the alert will fire when the number of samples per target scrape has exceeded 80% of the enforced sample limit of 50000. The for duration must also have passed before the alert will fire. The <number> in the expression scrape_samples_scraped/<number> > <threshold> must match the enforcedSampleLimit value defined in the user-workload-monitoring-config configmap object.
    10 The conditions for the ApproachingEnforcedSamplesLimit alert must be true for this duration before the alert is fired.
    11 Defines the severity for the ApproachingEnforcedSamplesLimit alert.

  2. Apply the configuration to the user-defined project:

    $ oc apply -f monitoring-stack-alerts.yaml
Additional resources

Configuring external alertmanager instances

The OpenShift Container Platform monitoring stack includes a local Alertmanager instance that routes alerts from Prometheus. You can add external Alertmanager instances by configuring the cluster-monitoring-config config map in either the openshift-monitoring project or the user-workload-monitoring-config project.

If you add the same external Alertmanager configuration for multiple clusters and disable the local instance for each cluster, you can then manage alert routing for multiple clusters by using a single external Alertmanager instance.

Prerequisites

  • You have installed the OpenShift CLI (oc).

  • If you are configuring core OpenShift Container Platform monitoring components in the openshift-monitoring project:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config config map.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config config map.

Procedure

  1. Edit the configmap object.

    • To configure additional Alertmanagers for routing alerts from core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config config map in the openshift-monitoring project:

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

      2. Add an additionalAlertmanagerConfigs: section under data/config.yaml/prometheusK8s.

      3. Add the configuration details for additional Alertmanagers in this section:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      additionalAlertmanagerConfigs:
      - <alertmanager_specification>

        For <alertmanager_specification>, substitute authentication and other configuration details for additional Alertmanager instances. Currently supported authentication methods are bearer token (bearerToken) and client TLS (tlsConfig). The following sample config map configures an additional Alertmanager using a bearer token with client TLS authentication:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      additionalAlertmanagerConfigs:
      - scheme: https
        pathPrefix: /
        timeout: "30s"
        apiVersion: v1
        bearerToken:
          name: alertmanager-bearer-token
          key: token
        tlsConfig:
          key:
            name: alertmanager-tls
            key: tls.key
          cert:
            name: alertmanager-tls
            key: tls.crt
          ca:
            name: alertmanager-tls
            key: tls.ca
        staticConfigs:
        - external-alertmanager1-remote.com
        - external-alertmanager1-remote2.com

    • To configure additional Alertmanager instances for routing alerts from user-defined projects:

      1. Edit the user-workload-monitoring-config config map in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Add a <component>/additionalAlertmanagerConfigs: section under data/config.yaml/.

      3. Add the configuration details for additional Alertmanagers in this section:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>:
      additionalAlertmanagerConfigs:
      - <alertmanager_specification>

        For <component>, substitute one of two supported external Alertmanager components: prometheus or thanosRuler.

        For <alertmanager_specification>, substitute authentication and other configuration details for additional Alertmanager instances. Currently supported authentication methods are bearer token (bearerToken) and client TLS (tlsConfig). The following sample config map configures an additional Alertmanager using Thanos Ruler with a bearer token and client TLS authentication:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
   thanosRuler:
     additionalAlertmanagerConfigs:
    - scheme: https
      pathPrefix: /
      timeout: "30s"
      apiVersion: v1
      bearerToken:
        name: alertmanager-bearer-token
        key: token
      tlsConfig:
        key:
          name: alertmanager-tls
          key: tls.key
        cert:
          name: alertmanager-tls
          key: tls.crt
        ca:
          name: alertmanager-tls
          key: tls.ca
      staticConfigs:
      - external-alertmanager1-remote.com
      - external-alertmanager1-remote2.com

        Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

  2. Save the file to apply the changes to the configmap object. The new component placement configuration is applied automatically.

Attaching additional labels to your time series and alerts

Using the external labels feature of Prometheus, you can attach custom labels to all time series and alerts leaving Prometheus.

Prerequisites

  • If you are configuring core OpenShift Container Platform monitoring components:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are configuring components that monitor user-defined projects:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object:

    • To attach custom labels to all time series and alerts leaving the Prometheus instance that monitors core OpenShift Container Platform projects:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Define a map of labels you want to add for every metric under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      externalLabels:
        <key>: <value> (1)
        1 Substitute <key>: <value> with a map of key-value pairs where <key> is a unique name for the new label and <value> is its value.

        Do not use prometheus or prometheus_replica as key names, because they are reserved and will be overwritten.

        For example, to add metadata about the region and environment to all time series and alerts, use:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      externalLabels:
        region: eu
        environment: prod

    • To attach custom labels to all time series and alerts leaving the Prometheus instance that monitors user-defined projects:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Define a map of labels you want to add for every metric under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      externalLabels:
        <key>: <value> (1)
        1 Substitute <key>: <value> with a map of key-value pairs where <key> is a unique name for the new label and <value> is its value.

        Do not use prometheus or prometheus_replica as key names, because they are reserved and will be overwritten.

        In the openshift-user-workload-monitoring project, Prometheus handles metrics and Thanos Ruler handles alerting and recording rules. Setting externalLabels for prometheus in the user-workload-monitoring-config configmap object will only configure external labels for metrics and not for any rules.

        For example, to add metadata about the region and environment to all time series and alerts related to user-defined projects, use:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      externalLabels:
        region: eu
        environment: prod

  2. Save the file to apply the changes. The new configuration is applied automatically.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.
Additional resources

Setting log levels for monitoring components

You can configure the log level for Alertmanager, Prometheus Operator, Prometheus, Thanos Querier, and Thanos Ruler.

The following log levels can be applied to the relevant component in the cluster-monitoring-config and user-workload-monitoring-config configmap objects:

  • debug. Log debug, informational, warning, and error messages.

  • info. Log informational, warning, and error messages.

  • warn. Log warning and error messages only.

  • error. Log error messages only.

The default log level is info.

Prerequisites

  • If you are setting a log level for Alertmanager, Prometheus Operator, Prometheus, or Thanos Querier in the openshift-monitoring project:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are setting a log level for Prometheus Operator, Prometheus, or Thanos Ruler in the openshift-user-workload-monitoring project:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the configmap object:

    • To set a log level for a component in the openshift-monitoring project:

      1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

      2. Add logLevel: <log_level> for a component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    <component>: (1)
      logLevel: <log_level> (2)
        1 The monitoring stack component for which you are setting a log level. For default platform monitoring, available component values are prometheusK8s, alertmanagerMain, prometheusOperator, and thanosQuerier.
        2 The log level to set for the component. The available values are error, warn, info, and debug. The default value is info.

    • To set a log level for a component in the openshift-user-workload-monitoring project:

      1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

        $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

      2. Add logLevel: <log_level> for a component under data/config.yaml:

        apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    <component>: (1)
      logLevel: <log_level> (2)
        1 The monitoring stack component for which you are setting a log level. For user workload monitoring, available component values are prometheus, prometheusOperator, and thanosRuler.
        2 The log level to set for the component. The available values are error, warn, info, and debug. The default value is info.

  2. Save the file to apply the changes. The pods for the component restarts automatically when you apply the log-level change.

    Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.

  3. Confirm that the log-level has been applied by reviewing the deployment or pod configuration in the related project. The following example checks the log level in the prometheus-operator deployment in the openshift-user-workload-monitoring project:

    $ oc -n openshift-user-workload-monitoring get deploy prometheus-operator -o yaml |  grep "log-level"
    Example output
            - --log-level=debug

  4. Check that the pods for the component are running. The following example lists the status of pods in the openshift-user-workload-monitoring project:

    $ oc -n openshift-user-workload-monitoring get pods

    If an unrecognized loglevel value is included in the configmap object, the pods for the component might not restart successfully.

Enabling the query log file for Prometheus

You can configure Prometheus to write all queries that have been run by the engine to a log file. You can do so for default platform monitoring and for user-defined workload monitoring.

Because log rotation is not supported, only enable this feature temporarily when you need to troubleshoot an issue. After you finish troubleshooting, disable query logging by reverting the changes you made to the configmap object to enable the feature.
Prerequisites

  • You have installed the OpenShift CLI (oc).

  • If you are enabling the query log file feature for Prometheus in the openshift-monitoring project:

    • You have access to the cluster as a user with the cluster-admin cluster role.

    • You have created the cluster-monitoring-config configmap object.

  • If you are enabling the query log file feature for Prometheus in the openshift-user-workload-monitoring project:

    • You have access to the cluster as a user with the cluster-admin cluster role, or as a user with the user-workload-monitoring-config-edit role in the openshift-user-workload-monitoring project.

    • You have created the user-workload-monitoring-config configmap object.

Procedure

  • To set the query log file for Prometheus in the openshift-monitoring project:

    1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

    2. Add queryLogFile: <path> for prometheusK8s under data/config.yaml:

      apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    prometheusK8s:
      queryLogFile: <path> (1)
      1 The full path to the file in which queries will be logged.

    3. Save the file to apply the changes.

      When you save changes to a monitoring config map, pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.

    4. Verify that the pods for the component are running. The following sample command lists the status of pods in the openshift-monitoring project:

      $ oc -n openshift-monitoring get pods

    5. Read the query log:

      $ oc -n openshift-monitoring exec prometheus-k8s-0 -- cat <path>

      Revert the setting in the config map after you have examined the logged query information.

  • To set the query log file for Prometheus in the openshift-user-workload-monitoring project:

    1. Edit the user-workload-monitoring-config configmap object in the openshift-user-workload-monitoring project:

      $ oc -n openshift-user-workload-monitoring edit configmap user-workload-monitoring-config

    2. Add queryLogFile: <path> for prometheus under data/config.yaml:

      apiVersion: v1
kind: configmap
metadata:
  name: user-workload-monitoring-config
  namespace: openshift-user-workload-monitoring
data:
  config.yaml: |
    prometheus:
      queryLogFile: <path> (1)
      1 The full path to the file in which queries will be logged.

    3. Save the file to apply the changes.

      Configurations applied to the user-workload-monitoring-config configmap object are not activated unless a cluster administrator has enabled monitoring for user-defined projects.

      When you save changes to a monitoring config map, pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.

    4. Verify that the pods for the component are running. The following example command lists the status of pods in the openshift-user-workload-monitoring project:

      $ oc -n openshift-user-workload-monitoring get pods

    5. Read the query log:

      $ oc -n openshift-user-workload-monitoring exec prometheus-user-workload-0 -- cat <path>

      Revert the setting in the config map after you have examined the logged query information.
Additional resources

Enabling query logging for Thanos Querier

For default platform monitoring in the openshift-monitoring project, you can enable the Cluster Monitoring Operator to log all queries run by Thanos Querier.

Because log rotation is not supported, only enable this feature temporarily when you need to troubleshoot an issue. After you finish troubleshooting, disable query logging by reverting the changes you made to the configmap object to enable the feature.
Prerequisites

  • You have installed the OpenShift CLI (oc).

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have created the cluster-monitoring-config configmap object.

Procedure

You can enable query logging for Thanos Querier in the openshift-monitoring project:

  1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

  2. Add a thanosQuerier section under data/config.yaml and add values as shown in the following example:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    thanosQuerier:
      enableRequestLogging: <value> (1)
      logLevel: <value> (2)
    1 Set the value to true to enable logging and false to disable logging. The default value is false.
    2 Set the value to debug, info, warn, or error. If no value exists for logLevel, the log level defaults to error.

  3. Save the file to apply the changes.

    When you save changes to a monitoring config map, pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.
Verification

  1. Verify that the Thanos Querier pods are running. The following sample command lists the status of pods in the openshift-monitoring project:

    $ oc -n openshift-monitoring get pods

  2. Run a test query using the following sample commands as a model:

    $ token=`oc sa get-token prometheus-k8s -n openshift-monitoring`
$ oc -n openshift-monitoring exec -c prometheus prometheus-k8s-0 -- curl -k -H "Authorization: Bearer $token" 'https://thanos-querier.openshift-monitoring.svc:9091/api/v1/query?query=cluster_version'

  3. Run the following command to read the query log:

    $ oc -n openshift-monitoring logs <thanos_querier_pod_name> -c thanos-query

    Because the thanos-querier pods are highly available (HA) pods, you might be able to see logs in only one pod.

  4. After you examine the logged query information, disable query logging by changing the enableRequestLogging value to false in the config map.

Additional resources

Setting audit log levels for the Prometheus Adapter

In default platform monitoring, you can configure the audit log level for the Prometheus Adapter.

Prerequisites

  • You have installed the OpenShift CLI (oc).

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have created the cluster-monitoring-config configmap object.

Procedure

You can set an audit log level for the Prometheus Adapter in the default openshift-monitoring project:

  1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

  2. Add profile: in the k8sPrometheusAdapter/audit section under data/config.yaml:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    k8sPrometheusAdapter:
      audit:
        profile: <audit_log_level> (1)
    1 The audit log level to apply to the Prometheus Adapter.

  3. Set the audit log level by using one of the following values for the profile: parameter:

    • None: Do not log events.

    • Metadata: Log only the metadata for the request, such as user, timestamp, and so forth. Do not log the request text and the response text. Metadata is the default audit log level.

    • Request: Log only the metadata and the request text but not the response text. This option does not apply for non-resource requests.

    • RequestResponse: Log event metadata, request text, and response text. This option does not apply for non-resource requests.

  4. Save the file to apply the changes. The pods for the Prometheus Adapter restart automatically when you apply the change.

    When changes are saved to a monitoring config map, the pods and other resources in the related project might be redeployed. The running monitoring processes in that project might also be restarted.
Verification

  1. In the config map, under k8sPrometheusAdapter/audit/profile, set the log level to Request and save the file.

  2. Confirm that the pods for the Prometheus Adapter are running. The following example lists the status of pods in the openshift-monitoring project:

    $ oc -n openshift-monitoring get pods

  3. Confirm that the audit log level and audit log file path are correctly configured:

    $ oc -n openshift-monitoring get deploy prometheus-adapter -o yaml
    Example output
    ...
  - --audit-policy-file=/etc/audit/request-profile.yaml
  - --audit-log-path=/var/log/adapter/audit.log

  4. Confirm that the correct log level has been applied in the prometheus-adapter deployment in the openshift-monitoring project:

    $ oc -n openshift-monitoring exec deploy/prometheus-adapter -c prometheus-adapter -- cat /etc/audit/request-profile.yaml
    Example output
    "apiVersion": "audit.k8s.io/v1"
"kind": "Policy"
"metadata":
  "name": "Request"
"omitStages":
- "RequestReceived"
"rules":
- "level": "Request"

    If you enter an unrecognized profile value for the Prometheus Adapter in the configmap object, no changes are made to the Prometheus Adapter, and an error is logged by the Cluster Monitoring Operator.

  5. Review the audit log for the Prometheus Adapter:

    $ oc -n openshift-monitoring exec -c <prometheus_adapter_pod_name> -- cat /var/log/adapter/audit.log
Additional resources

Disabling the default Grafana deployment

By default, a read-only Grafana instance is deployed with a collection of dashboards displaying cluster metrics. The Grafana instance is not user-configurable.

You can disable the Grafana deployment, causing the associated resources to be deleted from the cluster. You might do this if you do not need these dashboards and want to conserve resources in your cluster. You will still be able to view metrics and dashboards included in the web console. Grafana can be safely enabled again at any time.

Prerequisites

  • You have access to the cluster as a user with the cluster-admin role.

  • You have created the cluster-monitoring-config configmap object.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the cluster-monitoring-config configmap object in the openshift-monitoring project:

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

  2. Add enabled: false for the grafana component under data/config.yaml:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    grafana:
      enabled: false

  3. Save the file to apply the changes. The resources will begin to be removed automatically when you apply the change.

    This change results in some components, including Prometheus and the Thanos Querier, being restarted. This might lead to previously collected metrics being lost if you have not yet followed the steps in the "Configuring persistent storage" section.

  4. Check that the Grafana pod is no longer running. The following example lists the status of pods in the openshift-monitoring project:

    $ oc -n openshift-monitoring get pods

    It may take a few minutes after applying the change for these pods to terminate.
Additional resources

Disabling the local Alertmanager

A local Alertmanager that routes alerts from Prometheus instances is enabled by default in the openshift-monitoring project of the OpenShift Container Platform monitoring stack.

If you do not need the local Alertmanager, you can disable it by configuring the cluster-monitoring-config config map in the openshift-monitoring project.

Prerequisites

  • You have access to the cluster as a user with the cluster-admin cluster role.

  • You have created the cluster-monitoring-config config map.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Edit the cluster-monitoring-config config map in the openshift-monitoring project:

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

  2. Add enabled: false for the alertmanagerMain component under data/config.yaml:

    apiVersion: v1
kind: configmap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    alertmanagerMain:
      enabled: false

  3. Save the file to apply the changes. The Alertmanager instance is disabled automatically when you apply the change.

Additional resources

Next steps