Configuring the default broker class - Brokers | Eventing

You can use the config-br-defaults config map to specify default broker class settings for Knative Eventing. You can specify the default broker class for the entire cluster or for one or more namespaces. Currently the MTChannelBasedBroker and Kafka broker types are supported.

Prerequisites

You have administrator permissions on OpenShift Container Platform.
You have installed the OpenShift Serverless Operator and Knative Eventing on your cluster.
If you want to use the Knative broker for Apache Kafka as the default broker implementation, you must also install the KnativeKafka CR on your cluster.

Procedure

Modify the KnativeEventing custom resource to add configuration details for the config-br-defaults config map:

apiVersion: operator.knative.dev/v1beta1
kind: KnativeEventing
metadata:
  name: knative-eventing
  namespace: knative-eventing
spec:
  defaultBrokerClass: Kafka (1)
  config: (2)
    config-br-defaults: (3)
      default-br-config: |
        clusterDefault: (4)
          brokerClass: Kafka
          apiVersion: v1
          kind: ConfigMap
          name: kafka-broker-config (5)
          namespace: knative-eventing (6)
        namespaceDefaults: (7)
          my-namespace:
            brokerClass: MTChannelBasedBroker
            apiVersion: v1
            kind: ConfigMap
            name: config-br-default-channel (8)
            namespace: knative-eventing (9)
...

1	The default broker class for Knative Eventing.
2	In `spec.config`, you can specify the config maps that you want to add modified configurations for.
3	The `config-br-defaults` config map specifies the default settings for any broker that does not specify `spec.config` settings or a broker class.
4	The cluster-wide default broker class configuration. In this example, the default broker class implementation for the cluster is `Kafka`.
5	The `kafka-broker-config` config map specifies default settings for the Kafka broker. See "Configuring Knative broker for Apache Kafka settings" in the "Additional resources" section.
6	The namespace where the `kafka-broker-config` config map exists.
7	The namespace-scoped default broker class configuration. In this example, the default broker class implementation for the `my-namespace` namespace is `MTChannelBasedBroker`. You can specify default broker class implementations for multiple namespaces.
8	The `config-br-default-channel` config map specifies the default backing channel for the broker. See "Configuring the default broker backing channel" in the "Additional resources" section.
9	The namespace where the `config-br-default-channel` config map exists.

Configuring a namespace-specific default overrides any cluster-wide settings.