Chapter 16. Using a sink binding with Service Mesh

Procedure

1. Create a Service object in a namespace that is member of the ServiceMeshMemberRoll:

   Example event-display-service.yaml configuration file

   apiVersion: serving.knative.dev/v1
   kind: Service
   metadata:
     name: event-display
     namespace: <namespace> 

   1

   
   spec:
     template:
       metadata:
         annotations:
           sidecar.istio.io/inject: "true" 

   2

   
           sidecar.istio.io/rewriteAppHTTPProbers: "true"
       spec:
         containers:
         - image: quay.io/openshift-knative/knative-eventing-sources-event-display:latest

   1

   A namespace that is a member of the ServiceMeshMemberRoll.

   2

   This annotation injects Service Mesh sidecars into the Knative service pods.

2. Apply the Service object:

   $ oc apply -f event-display-service.yaml

3. Create a SinkBinding object:

   Example heartbeat-sinkbinding.yaml configuration file

   apiVersion: sources.knative.dev/v1alpha1
   kind: SinkBinding
   metadata:
     name: bind-heartbeat
     namespace: <namespace> 

   1

   
   spec:
     subject:
       apiVersion: batch/v1
       kind: Job 

   2

   
       selector:
         matchLabels:
           app: heartbeat-cron
   
     sink:
       ref:
         apiVersion: serving.knative.dev/v1
         kind: Service
         name: event-display

   1

   A namespace that is part of the ServiceMeshMemberRoll.

   2

   Bind any Job with the label app: heartbeat-cron to the event sink.

4. Apply the SinkBinding object:

   $ oc apply -f heartbeat-sinkbinding.yaml

5. Create a CronJob object:

   Example heartbeat-cronjob.yaml configuration file

   apiVersion: batch/v1
   kind: CronJob
   metadata:
     name: heartbeat-cron
     namespace: <namespace> 

   1

   
   spec:
     # Run every minute
     schedule: "* * * * *"
     jobTemplate:
       metadata:
         labels:
           app: heartbeat-cron
           bindings.knative.dev/include: "true"
       spec:
         template:
           metadata:
             annotations:
               sidecar.istio.io/inject: "true" 

   2

   
               sidecar.istio.io/rewriteAppHTTPProbers: "true"
           spec:
             restartPolicy: Never
             containers:
               - name: single-heartbeat
                 image: quay.io/openshift-knative/heartbeats:latest
                 args:
                   - --period=1
                 env:
                   - name: ONE_SHOT
                     value: "true"
                   - name: POD_NAME
                     valueFrom:
                       fieldRef:
                         fieldPath: metadata.name
                   - name: POD_NAMESPACE
                     valueFrom:
                       fieldRef:
                         fieldPath: metadata.namespace

   1

   A namespace that is part of the ServiceMeshMemberRoll.

   2

   Inject Service Mesh sidecars into the CronJob pods.

6. Apply the CronJob object:

   $ oc apply -f heartbeat-cronjob.yaml

7. Optional: Verify that the events were sent to the Knative event sink by looking at the message dumper function logs:

   Example command

   $ oc logs $(oc get pod -o name | grep event-display) -c user-container

   Example output

   ☁️  cloudevents.Event
   Validation: valid
   Context Attributes,
     specversion: 1.0
     type: dev.knative.eventing.samples.heartbeat
     source: https://knative.dev/eventing-contrib/cmd/heartbeats/#event-test/mypod
     id: 2b72d7bf-c38f-4a98-a433-608fbcdd2596
     time: 2019-10-18T15:23:20.809775386Z
     contenttype: application/json
   Extensions,
     beats: true
     heart: yes
     the: 42
   Data,
     {
       "id": 1,
       "label": ""
     }