Uninstall your operator

When uninstalling an operator managed by OLM, a Cluster Admin must decide whether or not to remove the CustomResourceDefinitions (CRD), APIServices, and resources related to these types owned by the operator. By design, when OLM uninstalls an operator it does not remove any of the operator’s owned CRDs, APIServices, or CRs in order to prevent data loss. Instead, it is left to the Cluster Admin to remove any unwanted types and resources from the cluster. This document will discuss the steps a Cluster Admin should take when uninstalling an operator.

Step 1: Identifying Resources to Remove

The cluster admin should first understand which types (CRDs and APIServices) are owned by the operator, which is available in the operator’s ClusterServiceVersion (CSV) under the spec.customresourcedefinitions.owned and spec.apiservicedefinitions.owned arrays. It is likely that users have created resources for these types since the operator was installed. The cluster admin should should decide which of these resources to delete on a case-by-case basis. If the resource is not required, delete it. The Cluster Admin should delete all unwanted resources before moving to the next step.

Note: Although deleting the CRD or APIService removes all resource of the type from the cluster, this action may lead to unintended consequences. Operators often use finalizers to execute application specific cleanup routines before removing the CR. If the API is removed, the operator will be unable to properly remove the resource, and the cluster may appear to be “stuck” as defined in this Kubernetes issue.

Step 2: Unsubscribe from the Operator

OLM uses the Subscription resource to convey a user’s intent to subscribe to the latest version of an operator. If the operator was installed with Automatic Updates (spec.InstallPlanApproval: "Automatic"), OLM will reinstall a new version of the operator even if the operator’s CSV was deleted earlier. In effect, you must tell OLM that you do not want new versions of the operator to be installed by deleting the Subscription associated with the operator. It should be noted that opting out of future upgrades by deleting a Subscription does not delete the associated CSV as this ensures that a specific version of the operator is available on cluster and is never upgraded.

You can list existing Subscription in a specific namespace with the following kubectl command:

$ kubectl get subscription -n <namespace>
# Example output
NAME                                                 PACKAGE              SOURCE            CHANNEL
foo-sub                                              foo                  foo-catalog       alpha

Note: The name of the operator installed by the Subscription is available under the Package column.

The Subscription can be deleted by running this command:

kubectl delete subscription <subscription-name> -n <namespace>

Step 3: Delete the Operator’s ClusterServiceVersion (CSV)

The CSV contains all the information that OLM needs to manage an operator, and it effectively represents an operator that is installed on cluster. By deleting a CSV, OLM will delete the resources it created for the operator such as the deployment, RBAC, and any corresponding CSVs that OLM “Copied” into other namespaces watched by the operator.

If you wish to look up a list of ClusterServiceVersion in a specific namespace to see which ClusterServiceVersion you need to delete, you can use the example kubectl command:

$ kubectl get clusterserviceversion -n <namespace>
# Example output
NAME                        DISPLAY              VERSION   REPLACES                    PHASE
foo                         Foo Operator         1.0.0                                 Succeeded

You can delete the ClusterServiceVersion in the namespace that the operator was installed into using this command:

kubectl delete clusterserviceversion <csv-name> -n <namespace>

Combine steps 2 and 3

Alternatively, you can delete both Subscription and its CSV using a sequence of commands:

CSV=$(kubectl get subscription <subscription-name> -n <namespace> -o json | jq -r '.status.installedCSV')
kubectl delete subscription <subscription-name> -n <namespace>
kubectl delete csv $CSV -n <namespace>

Step 4: Deciding whether or not to delete the CRDs and APIServices

The fourth step consists of deciding whether or not to delete the CRDs and APIServices that were introduced to the cluster by the operator. Assuming you have already deleted all unwanted resources on cluster as enumerated in Step 1, if no resources remain it is safe to remove the CRD or APISerivces. Otherwise, you should not delete the type as the wanted resources will be deleted automatically when the CRD or APISerivce is deleted.

Step 5: Deleting the Operator CR

OLM recently introduced the view-only operator CRD which communicates the list of resources associated with an operator bundle installed by OLM. When installing an operator bundle, OLM will create an operator CR named:

• <packageName> if the operator is All Namespaced scoped.
• <packageName>.<Namespace> if the operator is not All Namespaced scoped.

OLM will then the update the operator’s status.Components.Refs array to include all resources associated with the operator. Let’s consider OLM’s behavior after creating the operator CR named foo:

• All resources associated with the foo operator CR will have the operators.coreos.com/foo label applied to it.
• OLM will create or recreate the foo operator CR if any resources exist with the operators.coreos.com/foo label.

This ultimately means that in order to delete the foo operator CR, users will need to ensure that no resources are labeled with the operators.coreos.com/foo label. Typically, OLM should not attempt to recreate the foo operator after a user deletes it if they have completed steps 1 through 4 above. However, if OLM is still recreating the foo operator, a user should:

• Delete each resource found in the foo operator's status.Components.Refs array. Alternatively, if you have deleted the foo operator's CSV and Subscription you may remove the operators.coreos.com/foo label from any resources you do not wish to delete.
• Delete the foo operator CR. The final step consists of deciding whether or not to delete the CRDs and APIServices that were introduced to the cluster by the operator. Assuming you have already deleted all unwanted resources on cluster as enumerated in Step 1, if no resources remain it is safe to remove the CRD or APISerivces. Otherwise, you should not delete the type as the wanted resources will be deleted automatically when the CRD or APISerivce is deleted.