Upgrading using the Knative Operator

This topic describes how to upgrade Knative if you installed using the Operator. If you installed using YAML, see Upgrading with kubectl.

The attribute spec.version is the only field you need to change in the Serving or Eventing custom resource to perform an upgrade. You do not need to specify the version for the patch number, because the Knative Operator matches the latest available patch number, as long as you specify major.minor for the version. For example, you only need to specify "0.23" to upgrade to the 0.23 release, you do not need to specify the exact patch number.

The Knative Operator supports up to the last three major releases. For example, if the current version of the Operator is 0.23, it bundles and supports the installation of Knative versions 0.20, 0.21, 0.22 and 0.23.

Note

In the following examples, Knative Serving custom resources are installed in the knative-serving namespace, and Knative Eventing custom resources are installed in the knative-eventing namespace.

Performing the upgrade

To upgrade, apply the Operator custom resources, adding the spec.version for the Knative version that you want to upgrade to:

1. Create a YAML file containing the following:

   apiVersion: operator.knative.dev/v1alpha1
   kind: KnativeServing
   metadata:
     name: knative-serving
     namespace: knative-serving
   spec:
     version: "<new-version>"

   Where <new-version> is the Knative version that you want to upgrade to.

2. Apply the YAML file by running the command:

   kubectl apply -f <filename>.yaml

   Where <filename> is the name of the file you created in the previous step.

Verifying an upgrade by viewing pods

You can confirm that your Knative components have upgraded successfully, by viewing the status of the pods for the components in the relevant namespace.

Note

All pods will restart during the upgrade and their age will reset.

Knative ServingKnative Eventing

Enter the following command to view information about pods in the knative-serving namespace:

kubectl get pods --namespace knative-serving

The command returns an output similar to the following:

NAME                                                     READY   STATUS      RESTARTS   AGE
activator-6875896748-gdjgs                               1/1     Running     0          58s
autoscaler-6bbc885cfd-vkrgg                              1/1     Running     0          57s
autoscaler-hpa-5cdd7c6b69-hxzv4                          1/1     Running     0          55s
controller-64dd4bd56-wzb2k                               1/1     Running     0          57s
net-istio-webhook-75cc84fbd4-dkcgt                       1/1     Running     0          50s
net-istio-controller-6dcbd4b5f4-mxm8q                    1/1     Running     0          51s
storage-version-migration-serving-serving-0.20.0-82hjt   0/1     Completed   0          50s
webhook-75f5d4845d-zkrdt                                 1/1     Running     0          56s

Enter the following command to view information about pods in the knative-eventing namespace:

kubectl get pods --namespace knative-eventing

The command returns an output similar to the following:

NAME                                              READY   STATUS      RESTARTS   AGE
eventing-controller-6bc59c9fd7-6svbm              1/1     Running     0          38s
eventing-webhook-85cd479f87-4dwxh                 1/1     Running     0          38s
imc-controller-97c4fd87c-t9mnm                    1/1     Running     0          33s
imc-dispatcher-c6db95ffd-ln4mc                    1/1     Running     0          33s
mt-broker-controller-5f87fbd5d9-m69cd             1/1     Running     0          32s
mt-broker-filter-5b9c64cbd5-d27p4                 1/1     Running     0          32s
mt-broker-ingress-55c66fdfdf-gn56g                1/1     Running     0          32s
storage-version-migration-eventing-0.20.0-fvgqf   0/1     Completed   0          31s
sugar-controller-684d5cfdbb-67vsv                 1/1     Running     0          31s

Verifying an upgrade by viewing custom resources

You can verify the status of a Knative component by checking that the custom resource READY status is True.

Knative ServingKnative Eventing

kubectl get KnativeServing knative-serving --namespace knative-serving

This command returns an output similar to the following:

NAME              VERSION         READY   REASON
knative-serving   0.20.0          True

kubectl get KnativeEventing knative-eventing --namespace knative-eventing

This command returns an output similar to the following:

NAME               VERSION        READY   REASON
knative-eventing   0.20.0         True

Rollback to an earlier version

If the upgrade fails, you can rollback to restore your Knative to the previous version. For example, if something goes wrong with an upgrade to 0.23, and your previous version is 0.22, you can apply the following custom resources to restore Knative Serving and Knative Eventing to version 0.22.

Knative Serving

To rollback to a previous version of Knative Serving:

1. Create a YAML file containing the following:

   apiVersion: operator.knative.dev/v1alpha1
   kind: KnativeServing
   metadata:
     name: knative-serving
     namespace: knative-serving
   spec:
     version: "<previous-version>"

   Where <previous-version> is the Knative version that you want to downgrade to.

2. Apply the YAML file by running the command:

   kubectl apply -f <filename>.yaml

   Where <filename> is the name of the file you created in the previous step.

Knative Eventing

To rollback to a previous version of Knative Eventing:

1. Create a YAML file containing the following:

   apiVersion: operator.knative.dev/v1alpha1
   kind: KnativeEventing
   metadata:
     name: knative-eventing
     namespace: knative-eventing
   spec:
     version: "<previous-version>"

   Where <previous-version> is the Knative version that you want to downgrade to.

2. Apply the YAML file by running the command:

   kubectl apply -f <filename>.yaml

   Where <filename> is the name of the file you created in the previous step.