Understanding FeatureGates and Technology Preview features

You can use the FeatureGates Custom Resource to enable Technology Preview features throughout your cluster. This allows you, for example, to enable Technology Preview features on test clusters where you can fully test them while ensuring they are disabled on production clusters.

After turning Technology Preview features on using FeatureGates, they cannot be turned off and cluster upgrades are prevented.

For more information about the support scope of Red Hat Technology Preview features, see https://access.redhat.com/support/offerings/techpreview/.

Features that are affected by FeatureGates

The following features are affected by FeatureGates:

FeatureGate Description

CSIBlockVolume

Enables external CSI drivers to implement raw block volume support.

ExperimentalCriticalPodAnnotation

Enables annotating specific Pods as critical so that their scheduling is guaranteed.

MachineHealthCheck

Enables automatically repairing damaged machines in a machine pool.

RotateKubeletServerCertificate

Enables the rotation of the server TLS certificate on the cluster.

SupportPodPidsLimit

Enables support for limiting the number of processes (PIDs) running in a Pod.

Enabling Technology Preview features using FeatureGates

You can turn Technology Preview features on for all nodes in the cluster by editing the FeatureGates Custom Resource, named cluster, in the openshift-config project.

Turning on Technology Preview features cannot be undone and prevents upgrades.

Procedure

To turn on the Technology Preview features for the entire cluster:

  1. Create the FeatureGates instance:

    1. Switch to the the AdministrationCustom Resource Definitions page.

    2. On the Custom Resource Definitions page, click FeatureGate.

    3. On the Custom Resource Definitions page, click the Actions Menu and select View Instances.

    4. On the Feature Gates page, click Create Feature Gates.

    5. Replace the code with following sample:

      apiVersion: config.openshift.io/v1
      kind: FeatureGate
      metadata:
        name: cluster
      spec: {}
    6. Click Create.

  2. To turn on the Technology Preview features, change the spec parameter to:

    apiVersion: config.openshift.io/v1
    kind: FeatureGate
    metadata:
      name: cluster
    spec:
      featureSet: TechPreviewNoUpgrade (1)
    1 Add featureSet: TechPreviewNoUpgrade to enable the Technology Preview features that are affected by FeatureGates.