11.4. Using a ping source

Procedure

1. To verify that the ping source is working, create a simple Knative service that dumps incoming messages to the service’s logs:

   $ kn service create event-display \
       --image quay.io/openshift-knative/knative-eventing-sources-event-display:latest

2. For each set of ping events that you want to request, create a PingSource object in the same namespace as the event consumer:

   $ kn source ping create test-ping-source \
       --schedule "*/2 * * * *" \
       --data '{"message": "Hello world!"}' \
       --sink ksvc:event-display

3. Check that the controller is mapped correctly by entering the following command and inspecting the output:

   $ kn source ping describe test-ping-source

   Example output

   Name:         test-ping-source
   Namespace:    default
   Annotations:  sources.knative.dev/creator=developer, sources.knative.dev/lastModifier=developer
   Age:          15s
   Schedule:     */2 * * * *
   Data:         {"message": "Hello world!"}
   
   Sink:
     Name:       event-display
     Namespace:  default
     Resource:   Service (serving.knative.dev/v1)
   
   Conditions:
     OK TYPE                 AGE REASON
     ++ Ready                 8s
     ++ Deployed              8s
     ++ SinkProvided         15s
     ++ ValidSchedule        15s
     ++ EventTypeProvided    15s
     ++ ResourcesCorrect     15s

1. Watch for new pods created:

   $ watch oc get pods

2. Cancel watching the pods using Ctrl+C, then look at the logs of the created pod:

   $ 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.sources.ping
     source: /apis/v1/namespaces/default/pingsources/test-ping-source
     id: 99e4f4f6-08ff-4bff-acf1-47f61ded68c9
     time: 2020-04-07T16:16:00.000601161Z
     datacontenttype: application/json
   Data,
     {
       "message": "Hello world!"
     }

Procedure

1. To verify that the ping source is working, create a simple Knative service that dumps incoming messages to the log of the service.

   1. Copy the example YAML into a file named service.yaml:

      apiVersion: serving.knative.dev/v1
      kind: Service
      metadata:
        name: event-display
      spec:
        template:
          spec:
            containers:
              - image: quay.io/openshift-knative/knative-eventing-sources-event-display:latest

   2. Apply the service.yaml file:

      $ oc apply --filename service.yaml

2. For each set of ping events that you want to request, create a PingSource object in the same namespace as the event consumer.

   1. Copy the example YAML into a file named ping-source.yaml:

      apiVersion: sources.knative.dev/v1alpha2
      kind: PingSource
      metadata:
        name: test-ping-source
      spec:
        schedule: "*/2 * * * *"
        jsonData: '{"message": "Hello world!"}'
        sink:
          ref:
            apiVersion: serving.knative.dev/v1
            kind: Service
            name: event-display

   2. Apply the ping-source.yaml file:

      $ oc apply --filename ping-source.yaml

3. Check that the controller is mapped correctly by entering the following command and observing the output:

   $ oc get pingsource.sources.knative.dev test-ping-source -oyaml

   Example output

   apiVersion: sources.knative.dev/v1alpha2
   kind: PingSource
   metadata:
     annotations:
       sources.knative.dev/creator: developer
       sources.knative.dev/lastModifier: developer
     creationTimestamp: "2020-04-07T16:11:14Z"
     generation: 1
     name: test-ping-source
     namespace: default
     resourceVersion: "55257"
     selfLink: /apis/sources.knative.dev/v1alpha2/namespaces/default/pingsources/test-ping-source
     uid: 3d80d50b-f8c7-4c1b-99f7-3ec00e0a8164
   spec:
     jsonData: '{ value: "hello" }'
     schedule: '*/2 * * * *'
     sink:
       ref:
         apiVersion: serving.knative.dev/v1
         kind: Service
         name: event-display
         namespace: default

1. Watch for new pods created:

   $ watch oc get pods

2. Cancel watching the pods using Ctrl+C, then look at the logs of the created pod:

   $ 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.sources.ping
     source: /apis/v1/namespaces/default/pingsources/test-ping-source
     id: 042ff529-240e-45ee-b40c-3a908129853e
     time: 2020-04-07T16:22:00.000791674Z
     datacontenttype: application/json
   Data,
     {
       "message": "Hello world!"
     }