Operators are a method of packaging, deploying, and managing an OKD application. They act like an extension of the software vendor’s engineering team, watching over an OKD environment and using its current state to make decisions in real time. Operators are designed to handle upgrades seamlessly, react to failures automatically, and not take shortcuts, such as skipping a software backup process to save time.

OKD 4.8 includes a default set of Operators that are required for proper functioning of the cluster. These default Operators are managed by the Cluster Version Operator (CVO).

As a cluster administrator, you can install application Operators from the OperatorHub using the OKD web console or the CLI. You can then subscribe the Operator to one or more namespaces to make it available for developers on your cluster. Application Operators are managed by Operator Lifecycle Manager (OLM).

If you experience Operator issues, verify Operator subscription status. Check Operator pod health across the cluster and gather Operator logs for diagnosis.

Operator subscription condition types

Subscriptions can report the following condition types:

Table 1. Subscription condition types
Condition Description

CatalogSourcesUnhealthy

Some or all of the catalog sources to be used in resolution are unhealthy.

InstallPlanMissing

An install plan for a subscription is missing.

InstallPlanPending

An install plan for a subscription is pending installation.

InstallPlanFailed

An install plan for a subscription has failed.

Default OKD cluster Operators are managed by the Cluster Version Operator (CVO) and they do not have a Subscription object. Application Operators are managed by Operator Lifecycle Manager (OLM) and they have a Subscription object.

Viewing Operator subscription status by using the CLI

You can view Operator subscription status by using the CLI.

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

  • You have installed the OpenShift CLI (oc).

Procedure
  1. List Operator subscriptions:

    $ oc get subs -n <operator_namespace>
  2. Use the oc describe command to inspect a Subscription resource:

    $ oc describe sub <subscription_name> -n <operator_namespace>
  3. In the command output, find the Conditions section for the status of Operator subscription condition types. In the following example, the CatalogSourcesUnhealthy condition type has a status of false because all available catalog sources are healthy:

    Example output
    Conditions:
       Last Transition Time:  2019-07-29T13:42:57Z
       Message:               all available catalogsources are healthy
       Reason:                AllCatalogSourcesHealthy
       Status:                False
       Type:                  CatalogSourcesUnhealthy

Default OKD cluster Operators are managed by the Cluster Version Operator (CVO) and they do not have a Subscription object. Application Operators are managed by Operator Lifecycle Manager (OLM) and they have a Subscription object.

Viewing Operator catalog source status by using the CLI

You can view the status of an Operator catalog source by using the CLI.

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

  • You have installed the OpenShift CLI (oc).

Procedure
  1. List the catalog sources in a namespace. For example, you can check the olm namespace, which is used for cluster-wide catalog sources:

    $ oc get catalogsources -n olm
    Example output
    NAME                  DISPLAY               TYPE   PUBLISHER   AGE
    certified-operators   Certified Operators   grpc   Red Hat     55m
    community-operators   Community Operators   grpc   Red Hat     55m
    example-catalog       Example Catalog       grpc   Example Org 2m25s
    redhat-marketplace    Red Hat Marketplace   grpc   Red Hat     55m
    redhat-operators      Red Hat Operators     grpc   Red Hat     55m
  2. Use the oc describe command to get more details and status about a catalog source:

    $ oc describe catalogsource example-catalog -n olm
    Example output
    Name:         example-catalog
    Namespace:    olm
    ...
    Status:
      Connection State:
        Address:              example-catalog.olm.svc:50051
        Last Connect:         2021-09-09T17:07:35Z
        Last Observed State:  TRANSIENT_FAILURE
      Registry Service:
        Created At:         2021-09-09T17:05:45Z
        Port:               50051
        Protocol:           grpc
        Service Name:       example-catalog
        Service Namespace:  olm

    In the preceding example output, the last observed state is TRANSIENT_FAILURE. This state indicates that there is a problem establishing a connection for the catalog source.

  3. List the pods in the namespace where your catalog source was created:

    $ oc get pods -n olm
    Example output
    NAME                                    READY   STATUS             RESTARTS   AGE
    certified-operators-cv9nn               1/1     Running            0          36m
    community-operators-6v8lp               1/1     Running            0          36m
    marketplace-operator-86bfc75f9b-jkgbc   1/1     Running            0          42m
    example-catalog-bwt8z                   0/1     ImagePullBackOff   0          3m55s
    redhat-marketplace-57p8c                1/1     Running            0          36m
    redhat-operators-smxx8                  1/1     Running            0          36m

    When a catalog source is created in a namespace, a pod for the catalog source is created in that namespace. In the preceding example output, the status for the example-catalog-bwt8z pod is ImagePullBackOff. This status indicates that there is an issue pulling the catalog source’s index image.

  4. Use the oc describe command to inspect a pod for more detailed information:

    $ oc describe pod example-catalog-bwt8z -n olm
    Example output
    Name:         example-catalog-bwt8z
    Namespace:    olm
    Priority:     0
    Node:         ci-ln-jyryyg2-f76d1-ggdbq-worker-b-vsxjd/10.0.128.2
    ...
    Events:
      Type     Reason          Age                From               Message
      ----     ------          ----               ----               -------
      Normal   Scheduled       48s                default-scheduler  Successfully assigned olm/example-catalog-bwt8z to ci-ln-jyryyf2-f76d1-fgdbq-worker-b-vsxjd
      Normal   AddedInterface  47s                multus             Add eth0 [10.131.0.40/23] from openshift-sdn
      Normal   BackOff         20s (x2 over 46s)  kubelet            Back-off pulling image "quay.io/example-org/example-catalog:v1"
      Warning  Failed          20s (x2 over 46s)  kubelet            Error: ImagePullBackOff
      Normal   Pulling         8s (x3 over 47s)   kubelet            Pulling image "quay.io/example-org/example-catalog:v1"
      Warning  Failed          8s (x3 over 47s)   kubelet            Failed to pull image "quay.io/example-org/example-catalog:v1": rpc error: code = Unknown desc = reading manifest v1 in quay.io/example-org/example-catalog: unauthorized: access to the requested resource is not authorized
      Warning  Failed          8s (x3 over 47s)   kubelet            Error: ErrImagePull

    In the preceding example output, the error messages indicate that the catalog source’s index image is failing to pull successfully because of an authorization issue. For example, the index image might be stored in a registry that requires login credentials.

Querying Operator pod status

You can list Operator pods within a cluster and their status. You can also collect a detailed Operator pod summary.

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

  • Your API service is still functional.

  • You have installed the OpenShift CLI (oc).

Procedure
  1. List Operators running in the cluster. The output includes Operator version, availability, and up-time information:

    $ oc get clusteroperators
  2. List Operator pods running in the Operator’s namespace, plus pod status, restarts, and age:

    $ oc get pod -n <operator_namespace>
  3. Output a detailed Operator pod summary:

    $ oc describe pod <operator_pod_name> -n <operator_namespace>
  4. If an Operator issue is node-specific, query Operator container status on that node.

    1. Start a debug pod for the node:

      $ oc debug node/my-node
    2. Set /host as the root directory within the debug shell. The debug pod mounts the host’s root file system in /host within the pod. By changing the root directory to /host, you can run binaries contained in the host’s executable paths:

      # chroot /host

      OKD 4.8 cluster nodes running Fedora CoreOS (FCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. However, if the OKD API is not available, or the kubelet is not properly functioning on the target node, oc operations will be impacted. In such situations, it is possible to access nodes using ssh core@<node>.<cluster_name>.<base_domain> instead.

    3. List details about the node’s containers, including state and associated pod IDs:

      # crictl ps
    4. List information about a specific Operator container on the node. The following example lists information about the network-operator container:

      # crictl ps --name network-operator
    5. Exit from the debug shell.

Gathering Operator logs

If you experience Operator issues, you can gather detailed diagnostic information from Operator pod logs.

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

  • Your API service is still functional.

  • You have installed the OpenShift CLI (oc).

  • You have the fully qualified domain names of the control plane, or control plane machines (also known as the master machines).

Procedure
  1. List the Operator pods that are running in the Operator’s namespace, plus the pod status, restarts, and age:

    $ oc get pods -n <operator_namespace>
  2. Review logs for an Operator pod:

    $ oc logs pod/<pod_name> -n <operator_namespace>

    If an Operator pod has multiple containers, the preceding command will produce an error that includes the name of each container. Query logs from an individual container:

    $ oc logs pod/<operator_pod_name> -c <container_name> -n <operator_namespace>
  3. If the API is not functional, review Operator pod and container logs on each control plane node by using SSH instead. Replace <master-node>.<cluster_name>.<base_domain> with appropriate values.

    1. List pods on each control plane node:

      $ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl pods
    2. For any Operator pods not showing a Ready status, inspect the pod’s status in detail. Replace <operator_pod_id> with the Operator pod’s ID listed in the output of the preceding command:

      $ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspectp <operator_pod_id>
    3. List containers related to an Operator pod:

      $ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl ps --pod=<operator_pod_id>
    4. For any Operator container not showing a Ready status, inspect the container’s status in detail. Replace <container_id> with a container ID listed in the output of the preceding command:

      $ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl inspect <container_id>
    5. Review the logs for any Operator containers not showing a Ready status. Replace <container_id> with a container ID listed in the output of the preceding command:

      $ ssh core@<master-node>.<cluster_name>.<base_domain> sudo crictl logs -f <container_id>

      OKD 4.8 cluster nodes running Fedora CoreOS (FCOS) are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes using SSH is not recommended and nodes will be tainted as accessed. Before attempting to collect diagnostic data over SSH, review whether the data collected by running oc adm must gather and other oc commands is sufficient instead. However, if the OKD API is not available, or the kubelet is not properly functioning on the target node, oc operations will be impacted. In such situations, it is possible to access nodes using ssh core@<node>.<cluster_name>.<base_domain>.

Disabling the Machine Config Operator from automatically rebooting

When configuration changes are made by the Machine Config Operator (MCO), Fedora CoreOS (FCOS) must reboot for the changes to take effect. Whether the configuration change is automatic or manual, an FCOS node reboots automatically unless it is paused.

The following modifications do not trigger a node reboot:

  • When the MCO detects any of the following changes, it applies the update without draining or rebooting the node:

    • Changes to the SSH key in the spec.config.passwd.users.sshAuthorizedKeys parameter of a machine config.

    • Changes to the global pull secret or pull secret in the openshift-config namespace.

    • Automatic rotation of the /etc/kubernetes/kubelet-ca.crt certificate authority (CA) by the Kubernetes API Server Operator.

  • When the MCO detects changes to the /etc/containers/registries.conf file, such as adding or editing an ImageContentSourcePolicy object, it drains the corresponding nodes, applies the changes, and uncordons the nodes.

To avoid unwanted disruptions, you can modify the machine config pool (MCP) to prevent automatic rebooting after the Operator makes changes to the machine config.

Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc commands, including but not limited to oc debug, oc logs, oc exec, and oc attach. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer CA certificate expiration and for short periods of time only.

New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.

Disabling the Machine Config Operator from automatically rebooting by using the console

To avoid unwanted disruptions from changes made by the Machine Config Operator (MCO), you can use the OKD web console to modify the machine config pool (MCP) to prevent the MCO from making any changes to nodes in that pool. This prevents any reboots that would normally be part of the MCO update process.

Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc commands, including but not limited to oc debug, oc logs, oc exec, and oc attach. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer CA certificate expiration and for short periods of time only.

New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.

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

Procedure

To pause or unpause automatic MCO update rebooting:

  • Pause the autoreboot process:

    1. Log in to the OKD web console as a user with the cluster-admin role.

    2. Click ComputeMachine Config Pools.

    3. On the Machine Config Pools page, click either master or worker, depending upon which nodes you want to pause rebooting for.

    4. On the master or worker page, click YAML.

    5. In the YAML, update the spec.paused field to true.

      Sample MachineConfigPool object
      apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfigPool
       ...
      spec:
       ...
        paused: true (1)
      1 Update the spec.paused field to true to pause rebooting.
    6. To verify that the MCP is paused, return to the Machine Config Pools page.

      On the Machine Config Pools page, the Paused column reports True for the MCP you modified.

      If the MCP has pending changes while paused, the Updated column is False and Updating is False. When Updated is True and Updating is False, there are no pending changes.

      If there are pending changes (where both the Updated and Updating columns are False), it is recommended to schedule a maintenance window for a reboot as early as possible. Use the following steps for unpausing the autoreboot process to apply the changes that were queued since the last reboot.

  • Unpause the autoreboot process:

    1. Log in to the OKD web console as a user with the cluster-admin role.

    2. Click ComputeMachine Config Pools.

    3. On the Machine Config Pools page, click either master or worker, depending upon which nodes you want to pause rebooting for.

    4. On the master or worker page, click YAML.

    5. In the YAML, update the spec.paused field to false.

      Sample MachineConfigPool object
      apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfigPool
       ...
      spec:
       ...
        paused: false (1)
      1 Update the spec.paused field to false to allow rebooting.

      By unpausing an MCP, the MCO applies all paused changes reboots Fedora CoreOS (FCOS) as needed.

    6. To verify that the MCP is paused, return to the Machine Config Pools page.

      On the Machine Config Pools page, the Paused column reports False for the MCP you modified.

      If the MCP is applying any pending changes, the Updated column is False and the Updating column is True. When Updated is True and Updating is False, there are no further changes being made.

Disabling the Machine Config Operator from automatically rebooting by using the CLI

To avoid unwanted disruptions from changes made by the Machine Config Operator (MCO), you can modify the machine config pool (MCP) using the OpenShift CLI (oc) to prevent the MCO from making any changes to nodes in that pool. This prevents any reboots that would normally be part of the MCO update process.

Pausing an MCP prevents the MCO from applying any configuration changes on the associated nodes. Pausing an MCP also prevents any automatically-rotated certificates from being pushed to the associated nodes, including the automatic rotation of the kube-apiserver-to-kubelet-signer CA certificate. If the MCP is paused when the kube-apiserver-to-kubelet-signer CA certificate expires, and the MCO attempts to renew the certificate automatically, the new certificate is created but not applied across the nodes in the paused MCP. This causes failure in multiple oc commands, including but not limited to oc debug, oc logs, oc exec, and oc attach. Pausing an MCP should be done with careful consideration about the kube-apiserver-to-kubelet-signer CA certificate expiration and for short periods of time only.

New CA certificates are generated at 292 days from the installation date and removed at 365 days from that date. To determine the next automatic CA certificate rotation, see the Understand CA cert auto renewal in Red Hat OpenShift 4.

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

  • You have installed the OpenShift CLI (oc).

Procedure

To pause or unpause automatic MCO update rebooting:

  • Pause the autoreboot process:

    1. Update the MachineConfigPool custom resource to set the spec.paused field to true.

      Control plane (master) nodes
      $ oc patch --type=merge --patch='{"spec":{"paused":true}}' machineconfigpool/master
      Worker nodes
      $ oc patch --type=merge --patch='{"spec":{"paused":true}}' machineconfigpool/worker
    2. Verify that the MCP is paused:

      Control plane (master) nodes
      $ oc get machineconfigpool/master --template='{{.spec.paused}}'
      Worker nodes
      $ oc get machineconfigpool/worker --template='{{.spec.paused}}'
      Example output
      true

      The spec.paused field is true and the MCP is paused.

    3. Determine if the MCP has pending changes:

      # oc get machineconfigpool
      Example output
      NAME     CONFIG                                             UPDATED   UPDATING
      master   rendered-master-33cf0a1254318755d7b48002c597bf91   True      False
      worker   rendered-worker-e405a5bdb0db1295acea08bcca33fa60   False     False

      If the UPDATED column is False and UPDATING is False, there are pending changes. When UPDATED is True and UPDATING is False, there are no pending changes. In the previous example, the worker node has pending changes. The control plane node (also known as the master node) does not have any pending changes.

      If there are pending changes (where both the Updated and Updating columns are False), it is recommended to schedule a maintenance window for a reboot as early as possible. Use the following steps for unpausing the autoreboot process to apply the changes that were queued since the last reboot.

  • Unpause the autoreboot process:

    1. Update the MachineConfigPool custom resource to set the spec.paused field to false.

      Control plane (master) nodes
      $ oc patch --type=merge --patch='{"spec":{"paused":false}}' machineconfigpool/master
      Worker nodes
      $ oc patch --type=merge --patch='{"spec":{"paused":false}}' machineconfigpool/worker

      By unpausing an MCP, the MCO applies all paused changes and reboots Fedora CoreOS (FCOS) as needed.

    2. Verify that the MCP is unpaused:

      Control plane (master) nodes
      $ oc get machineconfigpool/master --template='{{.spec.paused}}'
      Worker nodes
      $ oc get machineconfigpool/worker --template='{{.spec.paused}}'
      Example output
      false

      The spec.paused field is false and the MCP is unpaused.

    3. Determine if the MCP has pending changes:

      $ oc get machineconfigpool
      Example output
      NAME     CONFIG                                   UPDATED  UPDATING
      master   rendered-master-546383f80705bd5aeaba93   True     False
      worker   rendered-worker-b4c51bb33ccaae6fc4a6a5   False    True

      If the MCP is applying any pending changes, the UPDATED column is False and the UPDATING column is True. When UPDATED is True and UPDATING is False, there are no further changes being made. In the previous example, the MCO is updating the worker node.

Refreshing failing subscriptions

In Operator Lifecycle Manager (OLM), if you subscribe to an Operator that references images that are not accessible on your network, you can find jobs in the openshift-marketplace namespace that are failing with the following errors:

Example output
ImagePullBackOff for
Back-off pulling image "example.com/openshift4/ose-elasticsearch-operator-bundle@sha256:6d2587129c846ec28d384540322b40b05833e7e00b25cca584e004af9a1d292e"
Example output
rpc error: code = Unknown desc = error pinging docker registry example.com: Get "https://example.com/v2/": dial tcp: lookup example.com on 10.0.0.1:53: no such host

As a result, the subscription is stuck in this failing state and the Operator is unable to install or upgrade.

You can refresh a failing subscription by deleting the subscription, cluster service version (CSV), and other related objects. After recreating the subscription, OLM then reinstalls the correct version of the Operator.

Prerequisites
  • You have a failing subscription that is unable to pull an inaccessible bundle image.

  • You have confirmed that the correct bundle image is accessible.

Procedure
  1. Get the names of the Subscription and ClusterServiceVersion objects from the namespace where the Operator is installed:

    $ oc get sub,csv -n <namespace>
    Example output
    NAME                                                       PACKAGE                  SOURCE             CHANNEL
    subscription.operators.coreos.com/elasticsearch-operator   elasticsearch-operator   redhat-operators   5.0
    
    NAME                                                                         DISPLAY                            VERSION    REPLACES   PHASE
    clusterserviceversion.operators.coreos.com/elasticsearch-operator.5.0.0-65   OpenShift Elasticsearch Operator   5.0.0-65              Succeeded
  2. Delete the subscription:

    $ oc delete subscription <subscription_name> -n <namespace>
  3. Delete the cluster service version:

    $ oc delete csv <csv_name> -n <namespace>
  4. Get the names of any failing jobs and related config maps in the openshift-marketplace namespace:

    $ oc get job,configmap -n openshift-marketplace
    Example output
    NAME                                                                        COMPLETIONS   DURATION   AGE
    job.batch/1de9443b6324e629ddf31fed0a853a121275806170e34c926d69e53a7fcbccb   1/1           26s        9m30s
    
    NAME                                                                        DATA   AGE
    configmap/1de9443b6324e629ddf31fed0a853a121275806170e34c926d69e53a7fcbccb   3      9m30s
  5. Delete the job:

    $ oc delete job <job_name> -n openshift-marketplace

    This ensures pods that try to pull the inaccessible image are not recreated.

  6. Delete the config map:

    $ oc delete configmap <configmap_name> -n openshift-marketplace
  7. Reinstall the Operator using OperatorHub in the web console.

Verification
  • Check that the Operator has been reinstalled successfully:

    $ oc get sub,csv,installplan -n <namespace>