Preparing to update to OKD 4.12

OKD 4.12 uses Kubernetes 1.25, which removed several deprecated APIs.

A cluster administrator must provide a manual acknowledgment before the cluster can be updated from OKD 4.11 to 4.12. This is to help prevent issues after upgrading to OKD 4.12, where APIs that have been removed are still in use by workloads, tools, or other components running on or interacting with the cluster. Administrators must evaluate their cluster for any APIs in use that will be removed and migrate the affected components to use the appropriate new API version. After this evaluation and migration is complete, the administrator can provide the acknowledgment.

Before you can update your OKD 4.11 cluster to 4.12, you must provide the administrator acknowledgment.

Removed Kubernetes APIs

OKD 4.12 uses Kubernetes 1.25, which removed the following deprecated APIs. You must migrate manifests and API clients to use the appropriate API version. For more information about migrating removed APIs, see the Kubernetes documentation.

Table 1. APIs removed from Kubernetes 1.25
ResourceRemoved APIMigrate toNotable changes

CronJob

batch/v1beta1

batch/v1

No

EndpointSlice

discovery.k8s.io/v1beta1

discovery.k8s.io/v1

Yes

Event

events.k8s.io/v1beta1

events.k8s.io/v1

Yes

HorizontalPodAutoscaler

autoscaling/v2beta1

autoscaling/v2

No

PodDisruptionBudget

policy/v1beta1

policy/v1

Yes

PodSecurityPolicy

policy/v1beta1

Pod Security Admission [1]

Yes

RuntimeClass

node.k8s.io/v1beta1

node.k8s.io/v1

No

  1. For more information about pod security admission in OKD, see Understanding and managing pod security admission.

Additional resources

Evaluating your cluster for removed APIs

There are several methods to help administrators identify where APIs that will be removed are in use. However, OKD cannot identify all instances, especially workloads that are idle or external tools that are used. It is the responsibility of the administrator to properly evaluate all workloads and other integrations for instances of removed APIs.

Reviewing alerts to identify uses of removed APIs

Two alerts fire when an API is in use that will be removed in the next release:

  • APIRemovedInNextReleaseInUse - for APIs that will be removed in the next OKD release.

  • APIRemovedInNextEUSReleaseInUse - for APIs that will be removed in the next OKD Extended Update Support (EUS) release.

If either of these alerts are firing in your cluster, review the alerts and take action to clear the alerts by migrating manifests and API clients to use the new API version.

Use the APIRequestCount API to get more information about which APIs are in use and which workloads are using removed APIs, because the alerts do not provide this information. Additionally, some APIs might not trigger these alerts but are still captured by APIRequestCount. The alerts are tuned to be less sensitive to avoid alerting fatigue in production systems.

Using APIRequestCount to identify uses of removed APIs

You can use the APIRequestCount API to track API requests and review whether any of them are using one of the removed APIs.

Prerequisites

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

Procedure

  • Run the following command and examine the REMOVEDINRELEASE column of the output to identify the removed APIs that are currently in use:

    1. $ oc get apirequestcounts

    Example output

    1. NAME                                                                      REMOVEDINRELEASE   REQUESTSINCURRENTHOUR   REQUESTSINLAST24H
    2. ...
    3. poddisruptionbudgets.v1.policy                                                               391                     8114
    4. poddisruptionbudgets.v1beta1.policy                                       1.25               2                       23
    5. podmonitors.v1.monitoring.coreos.com                                                         3                       70
    6. podnetworkconnectivitychecks.v1alpha1.controlplane.operator.openshift.io                     612                     11748
    7. pods.v1                                                                                      1531                    38634
    8. podsecuritypolicies.v1beta1.policy                                        1.25               3                       39
    9. podtemplates.v1                                                                              2                       79
    10. preprovisioningimages.v1alpha1.metal3.io                                                     2                       39
    11. priorityclasses.v1.scheduling.k8s.io                                                         12                      248
    12. prioritylevelconfigurations.v1beta1.flowcontrol.apiserver.k8s.io          1.26               3                       86
    13. ...

    You can safely ignore the following entries that appear in the results:

    • The system:serviceaccount:kube-system:generic-garbage-collector and the system:serviceaccount:kube-system:namespace-controller users might appear in the results because these services invoke all registered APIs when searching for resources to remove.

    • The system:kube-controller-manager and system:cluster-policy-controller users might appear in the results because they walk through all resources while enforcing various policies.

    You can also use -o jsonpath to filter the results:

    1. $ oc get apirequestcounts -o jsonpath='{range .items[?(@.status.removedInRelease!="")]}{.status.removedInRelease}{"\t"}{.metadata.name}{"\n"}{end}'

    Example output

    1. 1.26    flowschemas.v1beta1.flowcontrol.apiserver.k8s.io
    2. 1.26    horizontalpodautoscalers.v2beta2.autoscaling
    3. 1.25    poddisruptionbudgets.v1beta1.policy
    4. 1.25    podsecuritypolicies.v1beta1.policy
    5. 1.26    prioritylevelconfigurations.v1beta1.flowcontrol.apiserver.k8s.io

Using APIRequestCount to identify which workloads are using the removed APIs

You can examine the APIRequestCount resource for a given API version to help identify which workloads are using the API.

Prerequisites

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

Procedure

  • Run the following command and examine the username and userAgent fields to help identify the workloads that are using the API:

    1. $ oc get apirequestcounts <resource>.<version>.<group> -o yaml

    For example:

    1. $ oc get apirequestcounts poddisruptionbudgets.v1beta1.policy -o yaml

    You can also use -o jsonpath to extract the username and userAgent values from an APIRequestCount resource:

    1. $ oc get apirequestcounts poddisruptionbudgets.v1beta1.policy \
    2.   -o jsonpath='{range .status.currentHour..byUser[*]}{..byVerb[*].verb}{","}{.username}{","}{.userAgent}{"\n"}{end}' \
    3.   | sort -k 2 -t, -u | column -t -s, -NVERBS,USERNAME,USERAGENT

    Example output

    1. VERBS  USERNAME                                                                       USERAGENT
    2. watch  system:serviceaccount:openshift-operators:3scale-operator                      manager/v0.0.0
    3. watch  system:serviceaccount:openshift-operators:datadog-operator-controller-manager  manager/v0.0.0

Migrating instances of removed APIs

For information about how to migrate removed Kubernetes APIs, see the Deprecated API Migration Guide in the Kubernetes documentation.

Providing the administrator acknowledgment

After you have evaluated your cluster for any removed APIs and have migrated any removed APIs, you can acknowledge that your cluster is ready to upgrade from OKD 4.11 to 4.12.

Be aware that all responsibility falls on the administrator to ensure that all uses of removed APIs have been resolved and migrated as necessary before providing this administrator acknowledgment. OKD can assist with the evaluation, but cannot identify all possible uses of removed APIs, especially idle workloads or external tools.

Prerequisites

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

Procedure

  • Run the following command to acknowledge that you have completed the evaluation and your cluster is ready for the Kubernetes API removals in OKD 4.12:

    1. $ oc -n openshift-config patch cm admin-acks --patch '{"data":{"ack-4.11-kube-1.25-api-removals-in-4.12":"true"}}' --type=merge