Publishing Events

Finally, let’s publish some events. The broker can only be accessed from within the cluster where Knative Eventing is installed. We will create a pod within that cluster to act as an event producer that will execute the curl commands.

kubectl apply -f - << EOF
apiVersion: v1
kind: Pod
metadata:
  labels:
    run: post-event
  name: post-event
spec:
  containers:
    # This could be any image that we can SSH into and has curl.
  - image: radial/busyboxplus:curl
    imagePullPolicy: IfNotPresent
    name: post-event
    resources: {}
    stdin: true
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    tty: true
EOF
# wait for it to be ready
kubectl wait pods/post-event --for=condition=ContainersReady --timeout=90s
```{{execute}}

Let us publish some [cloudevents](https://cloudevents.io/). The command below adds some cloud-events specific headers to the curl command.

Publish `red` events using the command:

kubectl exec post-event – curl -v “http://broker-ingress.knative-eventing.svc.cluster.local/default/default"
-X POST
-H “Ce-Id: test”
-H “Ce-Specversion: 1.0”
-H “Ce-Type: red”
-H “Ce-Source: kata-tutorial”
-H “Content-Type: application/json”
-d ‘{“msg”:“The event is red!"}’

Publish `blue` events using the command:

kubectl exec post-event – curl -v “http://broker-ingress.knative-eventing.svc.cluster.local/default/default"
-X POST
-H “Ce-Id: test”
-H “Ce-Specversion: 1.0”
-H “Ce-Type: blue”
-H “Ce-Source: kata-tutorial”
-H “Content-Type: application/json”
-d ‘{“msg”:“The event is blue!"}’

Publish `orange` events using the command:

kubectl exec post-event – curl -v “http://broker-ingress.knative-eventing.svc.cluster.local/default/default"
-X POST
-H “Ce-Id: test”
-H “Ce-Specversion: 1.0”
-H “Ce-Type: orange”
-H “Ce-Source: kata-tutorial”
-H “Content-Type: application/json”
-d ‘{“msg”:“The event is orange!"}’

Verify that consumer1 receives blue and orange events and consumer2 receives red events:

it is likely that is pod is still being created after scaling down to zero

kubectl wait –for=condition=ready pod -l serving.knative.dev/service=consumer1 –timeout=90s kubectl wait –for=condition=ready pod -l serving.knative.dev/service=consumer2 –timeout=90s

see the logs

kubectl logs -l serving.knative.dev/service=consumer1 -c user-container –since=10m –tail=50 kubectl logs -l serving.knative.dev/service=consumer2 -c user-container –since=10m –tail=50