Create Knative Source and Broker

In this section you will set up the Knative components that can invoke the HTTP endpoint of the services (aiml-moderate-reviews, aiml-sentiment-reviews & persist-reviews) whenever a new event occurs due to a product review being submitted. This is performed by using the components Knative Source, Broker and Triggers.

The red box in the diagram below highlights the Knative Kafka Source and Kafka Broker that you will be creating within this section.

1. Create Knative Broker

From the the top right corner of the OpenShift console, click on the (+) button and then Import Yaml dropdown option
Copy the following YAML (CRD) and click Create to create a Knative broker.
Note: There is just one broker for the entire solution, which will use triggers to route them to the right services thereby building a realtime event mesh.
```
apiVersion: eventing.knative.dev/v1
kind: Broker
metadata:
  name: globex-broker
  namespace: globex-serverless-{user_name}
```

2. Create Knative source

From the the top right corner of the OpenShift console, click on the (+) button and then Import Yaml dropdown option

Copy the following YAML to create a Knative KafkaSource.
Note that this KafkaSource reads from the specific three (3) topics that are defined in the YAML below, and refers to the globex-broker you created in the previous step.

apiVersion: sources.knative.dev/v1beta1
kind: KafkaSource
metadata:
  name: kafka-source
  namespace: globex-serverless-{user_name}
spec:
  bootstrapServers:
    - 'kafka-kafka-bootstrap.globex-mw-{user_name}.svc.cluster.local:9092'
  topics:
    - globex.reviews
    - reviews.moderated
    - reviews.sentiment
  net:
    sasl:
      enable: true
      password:
        secretKeyRef:
          key: password
          name: kafka-secret
      type:
        secretKeyRef:
          key: sasl.mechanism
          name: kafka-secret
      user:
        secretKeyRef:
          key: user
          name: kafka-secret
    tls:
      caCert: {}
      cert: {}
      key: {}
  sink:
    ref:
      apiVersion: eventing.knative.dev/v1
      kind: Broker
      name: globex-broker
      namespace: globex-serverless-{user_name}

The kafka-source is created and the Conditions are all true denoting that the creation is a success.
Navigate back to the {openshift_cluster_console}/topology/ns/globex-serverless-{user_name}?view=graph[Topology View, window="console"], to view the new Source and Broker you created.