Chapter 6. Cluster Operators reference This reference guide indexes the cluster Operators shipped by Red Hat that serve as the architectural foundation for OpenShift Container Platform. Cluster Operators are installed by default, unless otherwise noted, and are managed by the Cluster Version Operator (CVO). For more details on the control plane architecture, see Operators in OpenShift Container Platform . Cluster administrators can view cluster Operators in the OpenShift Container Platform web console from the Administration Cluster Settings page. Note Cluster Operators are not managed by Operator Lifecycle Manager (OLM) and OperatorHub. OLM and OperatorHub are part of the Operator Framework used in OpenShift Container Platform for installing and running optional add-on Operators . 6.1. Cloud Credential Operator Purpose The Cloud Credential Operator (CCO) manages cloud provider credentials as Kubernetes custom resource definitions (CRDs). The CCO syncs on CredentialsRequest custom resources (CRs) to allow OpenShift Container Platform components to request cloud provider credentials with the specific permissions that are required for the cluster to run. By setting different values for the credentialsMode parameter in the install-config.yaml file, the CCO can be configured to operate in several different modes. If no mode is specified, or the credentialsMode parameter is set to an empty string ( "" ), the CCO operates in its default mode. Project openshift-cloud-credential-operator CRDs credentialsrequests.cloudcredential.openshift.io Scope: Namespaced CR: CredentialsRequest Validation: Yes Configuration objects No configuration required. Additional resources CredentialsRequest custom resource About the Cloud Credential Operator 6.2. Cluster Authentication Operator Purpose The Cluster Authentication Operator installs and maintains the Authentication custom resource in a cluster and can be viewed with: USD oc get clusteroperator authentication -o yaml Project cluster-authentication-operator 6.3. Cluster Autoscaler Operator Purpose The Cluster Autoscaler Operator manages deployments of the OpenShift Cluster Autoscaler using the cluster-api provider. Project cluster-autoscaler-operator CRDs ClusterAutoscaler : This is a singleton resource, which controls the configuration autoscaler instance for the cluster. The Operator only responds to the ClusterAutoscaler resource named default in the managed namespace, the value of the WATCH_NAMESPACE environment variable. MachineAutoscaler : This resource targets a node group and manages the annotations to enable and configure autoscaling for that group, the min and max size. Currently only MachineSet objects can be targeted. 6.4. Cluster Cloud Controller Manager Operator Purpose Note This Operator is only fully supported for Azure Stack Hub. It is available as a Technology Preview for Amazon Web Services (AWS), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP). The Cluster Cloud Controller Manager Operator manages and updates the cloud controller managers deployed on top of OpenShift Container Platform. The Operator is based on the Kubebuilder framework and controller-runtime libraries. It is installed via the Cluster Version Operator (CVO). It contains the following components: Operator Cloud configuration observer By default, the Operator exposes Prometheus metrics through the metrics service. Project cluster-cloud-controller-manager-operator 6.5. Cluster Config Operator Purpose The Cluster Config Operator performs the following tasks related to config.openshift.io : Creates CRDs. Renders the initial custom resources. Handles migrations. Project cluster-config-operator 6.6. Cluster CSI Snapshot Controller Operator Purpose The Cluster CSI Snapshot Controller Operator installs and maintains the CSI Snapshot Controller. The CSI Snapshot Controller is responsible for watching the VolumeSnapshot CRD objects and manages the creation and deletion lifecycle of volume snapshots. Project cluster-csi-snapshot-controller-operator 6.7. Cluster Image Registry Operator Purpose The Cluster Image Registry Operator manages a singleton instance of the OpenShift Container Platform registry. It manages all configuration of the registry, including creating storage. On initial start up, the Operator creates a default image-registry resource instance based on the configuration detected in the cluster. This indicates what cloud storage type to use based on the cloud provider. If insufficient information is available to define a complete image-registry resource, then an incomplete resource is defined and the Operator updates the resource status with information about what is missing. The Cluster Image Registry Operator runs in the openshift-image-registry namespace and it also manages the registry instance in that location. All configuration and workload resources for the registry reside in that namespace. Project cluster-image-registry-operator 6.8. Cluster Machine Approver Operator Purpose The Cluster Machine Approver Operator automatically approves the CSRs requested for a new worker node after cluster installation. Note For the control plane node, the approve-csr service on the bootstrap node automatically approves all CSRs during the cluster bootstrapping phase. Project cluster-machine-approver-operator 6.9. Cluster Monitoring Operator Purpose The Cluster Monitoring Operator manages and updates the Prometheus-based cluster monitoring stack deployed on top of OpenShift Container Platform. Project openshift-monitoring CRDs alertmanagers.monitoring.coreos.com Scope: Namespaced CR: alertmanager Validation: Yes prometheuses.monitoring.coreos.com Scope: Namespaced CR: prometheus Validation: Yes prometheusrules.monitoring.coreos.com Scope: Namespaced CR: prometheusrule Validation: Yes servicemonitors.monitoring.coreos.com Scope: Namespaced CR: servicemonitor Validation: Yes Configuration objects USD oc -n openshift-monitoring edit cm cluster-monitoring-config 6.10. Cluster Network Operator Purpose The Cluster Network Operator installs and upgrades the networking components on an OpenShift Container Platform cluster. 6.11. Cluster Samples Operator Purpose The Cluster Samples Operator manages the sample image streams and templates stored in the openshift namespace. On initial start up, the Operator creates the default samples configuration resource to initiate the creation of the image streams and templates. The configuration object is a cluster scoped object with the key cluster and type configs.samples . The image streams are the Red Hat Enterprise Linux CoreOS (RHCOS)-based OpenShift Container Platform image streams pointing to images on registry.redhat.io . Similarly, the templates are those categorized as OpenShift Container Platform templates. The Cluster Samples Operator deployment is contained within the openshift-cluster-samples-operator namespace. On start up, the install pull secret is used by the image stream import logic in the internal registry and API server to authenticate with registry.redhat.io . An administrator can create any additional secrets in the openshift namespace if they change the registry used for the sample image streams. If created, those secrets contain the content of a config.json for docker needed to facilitate image import. The image for the Cluster Samples Operator contains image stream and template definitions for the associated OpenShift Container Platform release. After the Cluster Samples Operator creates a sample, it adds an annotation that denotes the OpenShift Container Platform version that it is compatible with. The Operator uses this annotation to ensure that each sample matches the compatible release version. Samples outside of its inventory are ignored, as are skipped samples. Modifications to any samples that are managed by the Operator are allowed as long as the version annotation is not modified or deleted. However, on an upgrade, as the version annotation will change, those modifications can get replaced as the sample will be updated with the newer version. The Jenkins images are part of the image payload from the installation and are tagged into the image streams directly. The samples resource includes a finalizer, which cleans up the following upon its deletion: Operator-managed image streams Operator-managed templates Operator-generated configuration resources Cluster status resources Upon deletion of the samples resource, the Cluster Samples Operator recreates the resource using the default configuration. Project cluster-samples-operator 6.12. Cluster Storage Operator Purpose The Cluster Storage Operator sets OpenShift Container Platform cluster-wide storage defaults. It ensures a default storage class exists for OpenShift Container Platform clusters. Project cluster-storage-operator Configuration No configuration is required. Notes The Cluster Storage Operator supports Amazon Web Services (AWS) and Red Hat OpenStack Platform (RHOSP). The created storage class can be made non-default by editing its annotation, but the storage class cannot be deleted as long as the Operator runs. 6.13. Cluster Version Operator Purpose Cluster Operators manage specific areas of cluster functionality. The Cluster Version Operator (CVO) manages the lifecycle of cluster Operators, many of which are installed in OpenShift Container Platform by default. The CVO also checks with the OpenShift Update Service to see the valid updates and update paths based on current component versions and information in the graph. Project cluster-version-operator Additional resources Operators in OpenShift Container Platform 6.14. Console Operator Purpose The Console Operator installs and maintains the OpenShift Container Platform web console on a cluster. Project console-operator 6.15. DNS Operator Purpose The DNS Operator deploys and manages CoreDNS to provide a name resolution service to pods that enables DNS-based Kubernetes Service discovery in OpenShift Container Platform. The Operator creates a working default deployment based on the cluster's configuration. The default cluster domain is cluster.local . Configuration of the CoreDNS Corefile or Kubernetes plugin is not yet supported. The DNS Operator manages CoreDNS as a Kubernetes daemon set exposed as a service with a static IP. CoreDNS runs on all nodes in the cluster. Project cluster-dns-operator 6.16. etcd cluster Operator Purpose The etcd cluster Operator automates etcd cluster scaling, enables etcd monitoring and metrics, and simplifies disaster recovery procedures. Project cluster-etcd-operator CRDs etcds.operator.openshift.io Scope: Cluster CR: etcd Validation: Yes Configuration objects USD oc edit etcd cluster 6.17. Ingress Operator Purpose The Ingress Operator configures and manages the OpenShift Container Platform router. Project openshift-ingress-operator CRDs clusteringresses.ingress.openshift.io Scope: Namespaced CR: clusteringresses Validation: No Configuration objects Cluster config Type Name: clusteringresses.ingress.openshift.io Instance Name: default View Command: USD oc get clusteringresses.ingress.openshift.io -n openshift-ingress-operator default -o yaml Notes The Ingress Operator sets up the router in the openshift-ingress project and creates the deployment for the router: USD oc get deployment -n openshift-ingress The Ingress Operator uses the clusterNetwork[].cidr from the network/cluster status to determine what mode (IPv4, IPv6, or dual stack) the managed ingress controller (router) should operate in. For example, if clusterNetwork contains only a v6 cidr , then the ingress controller operate in IPv6-only mode. In the following example, ingress controllers managed by the Ingress Operator will run in IPv4-only mode because only one cluster network exists and the network is an IPv4 cidr : USD oc get network/cluster -o jsonpath='{.status.clusterNetwork[*]}' Example output map[cidr:10.128.0.0/14 hostPrefix:23] 6.18. Insights Operator Purpose The Insights Operator gathers OpenShift Container Platform configuration data and sends it to Red Hat. The data is used to produce proactive insights recommendations about potential issues that a cluster might be exposed to. These insights are communicated to cluster administrators through Insights Advisor on console.redhat.com . Project insights-operator Configuration No configuration is required. Notes Insights Operator compliments OpenShift Container Platform Telemetry. Additional resources About remote health monitoring for details about Insights Operator and Telemetry 6.19. Kubernetes API Server Operator Purpose The Kubernetes API Server Operator manages and updates the Kubernetes API server deployed on top of OpenShift Container Platform. The Operator is based on the OpenShift Container Platform library-go framework and it is installed using the Cluster Version Operator (CVO). Project openshift-kube-apiserver-operator CRDs kubeapiservers.operator.openshift.io Scope: Cluster CR: kubeapiserver Validation: Yes Configuration objects USD oc edit kubeapiserver 6.20. Kubernetes Controller Manager Operator Purpose The Kubernetes Controller Manager Operator manages and updates the Kubernetes Controller Manager deployed on top of OpenShift Container Platform. The Operator is based on OpenShift Container Platform library-go framework and it is installed via the Cluster Version Operator (CVO). It contains the following components: Operator Bootstrap manifest renderer Installer based on static pods Configuration observer By default, the Operator exposes Prometheus metrics through the metrics service. Project cluster-kube-controller-manager-operator 6.21. Kubernetes Scheduler Operator Purpose The Kubernetes Scheduler Operator manages and updates the Kubernetes Scheduler deployed on top of OpenShift Container Platform. The Operator is based on the OpenShift Container Platform library-go framework and it is installed with the Cluster Version Operator (CVO). The Kubernetes Scheduler Operator contains the following components: Operator Bootstrap manifest renderer Installer based on static pods Configuration observer By default, the Operator exposes Prometheus metrics through the metrics service. Project cluster-kube-scheduler-operator Configuration The configuration for the Kubernetes Scheduler is the result of merging: a default configuration. an observed configuration from the spec schedulers.config.openshift.io . All of these are sparse configurations, invalidated JSON snippets which are merged to form a valid configuration at the end. 6.22. Kubernetes Storage Version Migrator Operator Purpose The Kubernetes Storage Version Migrator Operator detects changes of the default storage version, creates migration requests for resource types when the storage version changes, and processes migration requests. Project cluster-kube-storage-version-migrator-operator 6.23. Machine API Operator Purpose The Machine API Operator manages the lifecycle of specific purpose custom resource definitions (CRD), controllers, and RBAC objects that extend the Kubernetes API. This declares the desired state of machines in a cluster. Project machine-api-operator CRDs MachineSet Machine MachineHealthCheck 6.24. Machine Config Operator Purpose The Machine Config Operator manages and applies configuration and updates of the base operating system and container runtime, including everything between the kernel and kubelet. There are four components: machine-config-server : Provides Ignition configuration to new machines joining the cluster. machine-config-controller : Coordinates the upgrade of machines to the desired configurations defined by a MachineConfig object. Options are provided to control the upgrade for sets of machines individually. machine-config-daemon : Applies new machine configuration during update. Validates and verifies the state of the machine to the requested machine configuration. machine-config : Provides a complete source of machine configuration at installation, first start up, and updates for a machine. Important Currently, there is no supported way to block or restrict the machine config server endpoint. The machine config server must be exposed to the network so that newly-provisioned machines, which have no existing configuration or state, are able to fetch their configuration. In this model, the root of trust is the certificate signing requests (CSR) endpoint, which is where the kubelet sends its certificate signing request for approval to join the cluster. Because of this, machine configs should not be used to distribute sensitive information, such as secrets and certificates. To ensure that the machine config server endpoints, ports 22623 and 22624, are secured in bare metal scenarios, customers must configure proper network policies. Additional resources About the OpenShift SDN network plugin . Project openshift-machine-config-operator 6.25. Marketplace Operator Purpose The Marketplace Operator is a conduit to bring off-cluster Operators to your cluster. Project operator-marketplace 6.26. Node Tuning Operator Purpose The Node Tuning Operator helps you manage node-level tuning by orchestrating the TuneD daemon. The majority of high-performance applications require some level of kernel tuning. The Node Tuning Operator provides a unified management interface to users of node-level sysctls and more flexibility to add custom tuning specified by user needs. The Operator manages the containerized TuneD daemon for OpenShift Container Platform as a Kubernetes daemon set. It ensures the custom tuning specification is passed to all containerized TuneD daemons running in the cluster in the format that the daemons understand. The daemons run on all nodes in the cluster, one per node. Node-level settings applied by the containerized TuneD daemon are rolled back on an event that triggers a profile change or when the containerized TuneD daemon is terminated gracefully by receiving and handling a termination signal. The Node Tuning Operator is part of a standard OpenShift Container Platform installation in version 4.1 and later. Project cluster-node-tuning-operator 6.27. OpenShift API Server Operator Purpose The OpenShift API Server Operator installs and maintains the openshift-apiserver on a cluster. Project openshift-apiserver-operator CRDs openshiftapiservers.operator.openshift.io Scope: Cluster CR: openshiftapiserver Validation: Yes 6.28. OpenShift Controller Manager Operator Purpose The OpenShift Controller Manager Operator installs and maintains the OpenShiftControllerManager custom resource in a cluster and can be viewed with: USD oc get clusteroperator openshift-controller-manager -o yaml The custom resource definitino (CRD) openshiftcontrollermanagers.operator.openshift.io can be viewed in a cluster with: USD oc get crd openshiftcontrollermanagers.operator.openshift.io -o yaml Project cluster-openshift-controller-manager-operator 6.29. Operator Lifecycle Manager Operators Purpose Operator Lifecycle Manager (OLM) helps users install, update, and manage the lifecycle of Kubernetes native applications (Operators) and their associated services running across their OpenShift Container Platform clusters. It is part of the Operator Framework , an open source toolkit designed to manage Operators in an effective, automated, and scalable way. Figure 6.1. Operator Lifecycle Manager workflow OLM runs by default in OpenShift Container Platform 4.9, which aids cluster administrators in installing, upgrading, and granting access to Operators running on their cluster. The OpenShift Container Platform web console provides management screens for cluster administrators to install Operators, as well as grant specific projects access to use the catalog of Operators available on the cluster. For developers, a self-service experience allows provisioning and configuring instances of databases, monitoring, and big data services without having to be subject matter experts, because the Operator has that knowledge baked into it. CRDs Operator Lifecycle Manager (OLM) is composed of two Operators: the OLM Operator and the Catalog Operator. Each of these Operators is responsible for managing the custom resource definitions (CRDs) that are the basis for the OLM framework: Table 6.1. CRDs managed by OLM and Catalog Operators Resource Short name Owner Description ClusterServiceVersion (CSV) csv OLM Application metadata: name, version, icon, required resources, installation, and so on. InstallPlan ip Catalog Calculated list of resources to be created to automatically install or upgrade a CSV. CatalogSource catsrc Catalog A repository of CSVs, CRDs, and packages that define an application. Subscription sub Catalog Used to keep CSVs up to date by tracking a channel in a package. OperatorGroup og OLM Configures all Operators deployed in the same namespace as the OperatorGroup object to watch for their custom resource (CR) in a list of namespaces or cluster-wide. Each of these Operators is also responsible for creating the following resources: Table 6.2. Resources created by OLM and Catalog Operators Resource Owner Deployments OLM ServiceAccounts (Cluster)Roles (Cluster)RoleBindings CustomResourceDefinitions (CRDs) Catalog ClusterServiceVersions OLM Operator The OLM Operator is responsible for deploying applications defined by CSV resources after the required resources specified in the CSV are present in the cluster. The OLM Operator is not concerned with the creation of the required resources; you can choose to manually create these resources using the CLI or using the Catalog Operator. This separation of concern allows users incremental buy-in in terms of how much of the OLM framework they choose to leverage for their application. The OLM Operator uses the following workflow: Watch for cluster service versions (CSVs) in a namespace and check that requirements are met. If requirements are met, run the install strategy for the CSV. Note A CSV must be an active member of an Operator group for the install strategy to run. Catalog Operator The Catalog Operator is responsible for resolving and installing cluster service versions (CSVs) and the required resources they specify. It is also responsible for watching catalog sources for updates to packages in channels and upgrading them, automatically if desired, to the latest available versions. To track a package in a channel, you can create a Subscription object configuring the desired package, channel, and the CatalogSource object you want to use for pulling updates. When updates are found, an appropriate InstallPlan object is written into the namespace on behalf of the user. The Catalog Operator uses the following workflow: Connect to each catalog source in the cluster. Watch for unresolved install plans created by a user, and if found: Find the CSV matching the name requested and add the CSV as a resolved resource. For each managed or required CRD, add the CRD as a resolved resource. For each required CRD, find the CSV that manages it. Watch for resolved install plans and create all of the discovered resources for it, if approved by a user or automatically. Watch for catalog sources and subscriptions and create install plans based on them. Catalog Registry The Catalog Registry stores CSVs and CRDs for creation in a cluster and stores metadata about packages and channels. A package manifest is an entry in the Catalog Registry that associates a package identity with sets of CSVs. Within a package, channels point to a particular CSV. Because CSVs explicitly reference the CSV that they replace, a package manifest provides the Catalog Operator with all of the information that is required to update a CSV to the latest version in a channel, stepping through each intermediate version. Additional resources Understanding Operator Lifecycle Manager (OLM) 6.30. OpenShift Service CA Operator Purpose The OpenShift Service CA Operator mints and manages serving certificates for Kubernetes services. Project openshift-service-ca-operator 6.31. vSphere Problem Detector Operator Purpose The vSphere Problem Detector Operator checks clusters that are deployed on vSphere for common installation and misconfiguration issues that are related to storage. Note The vSphere Problem Detector Operator is only started by the Cluster Storage Operator when the Cluster Storage Operator detects that the cluster is deployed on vSphere. Configuration No configuration is required. Notes The Operator supports OpenShift Container Platform installations on vSphere. The Operator uses the vsphere-cloud-credentials to communicate with vSphere. The Operator performs checks that are related to storage. Additional resources Using the vSphere Problem Detector Operator

Commands:
oc get clusteroperator authentication -o yaml
oc -n openshift-monitoring edit cm cluster-monitoring-config
oc edit etcd cluster
oc get clusteringresses.ingress.openshift.io -n openshift-ingress-operator default -o yaml
oc get deployment -n openshift-ingress
oc get network/cluster -o jsonpath='{.status.clusterNetwork[*]}'
map[cidr:10.128.0.0/14 hostPrefix:23]
oc edit kubeapiserver
oc get clusteroperator openshift-controller-manager -o yaml
oc get crd openshiftcontrollermanagers.operator.openshift.io -o yaml