2.5. Custom event sources

Procedure

1. To check that sink binding is set up correctly, create a Knative event display service, or event sink, that dumps incoming messages to its log.

   1. Create a service YAML file:

      Example service YAML file

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

   2. Create the service:

      $ oc apply -f <filename>

2. Create a sink binding instance that directs events to the service.

   1. Create a sink binding YAML file:

      Example service YAML file

      apiVersion: sources.knative.dev/v1alpha1
      kind: SinkBinding
      metadata:
        name: bind-heartbeat
      spec:
        subject:
          apiVersion: batch/v1
          kind: Job 

      1

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

      1

      In this example, any Job with the label app: heartbeat-cron will be bound to the event sink.

   2. Create the sink binding:

      $ oc apply -f <filename>

3. Create a CronJob object.

   1. Create a cron job YAML file:

      Example cron job YAML file

      apiVersion: batch/v1
      kind: CronJob
      metadata:
        name: heartbeat-cron
      spec:
        # Run every minute
        schedule: "* * * * *"
        jobTemplate:
          metadata:
            labels:
              app: heartbeat-cron
              bindings.knative.dev/include: "true"
          spec:
            template:
              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

      重要

      To use sink binding, you must manually add a bindings.knative.dev/include=true label to your Knative resources.

      For example, to add this label to a CronJob resource, add the following lines to the Job resource YAML definition:

        jobTemplate:
          metadata:
            labels:
              app: heartbeat-cron
              bindings.knative.dev/include: "true"

   2. Create the cron job:

      $ oc apply -f <filename>

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

   $ oc get sinkbindings.sources.knative.dev bind-heartbeat -oyaml

   Example output

   spec:
     sink:
       ref:
         apiVersion: serving.knative.dev/v1
         kind: Service
         name: event-display
         namespace: default
     subject:
       apiVersion: batch/v1
       kind: Job
       namespace: default
       selector:
         matchLabels:
           app: heartbeat-cron

1. Enter the command:

   $ oc get pods

2. Enter the 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": ""
     }

Procedure

1. To check that sink binding is set up correctly, create a Knative event display service, or event sink, that dumps incoming messages to its log:

   $ kn service create event-display --image quay.io/openshift-knative/showcase

2. Create a sink binding instance that directs events to the service:

   $ kn source binding create bind-heartbeat --subject Job:batch/v1:app=heartbeat-cron --sink ksvc:event-display

3. Create a CronJob object.

   1. Create a cron job YAML file:

      Example cron job YAML file

      apiVersion: batch/v1
      kind: CronJob
      metadata:
        name: heartbeat-cron
      spec:
        # Run every minute
        schedule: "* * * * *"
        jobTemplate:
          metadata:
            labels:
              app: heartbeat-cron
              bindings.knative.dev/include: "true"
          spec:
            template:
              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

      重要

      To use sink binding, you must manually add a bindings.knative.dev/include=true label to your Knative CRs.

      For example, to add this label to a CronJob CR, add the following lines to the Job CR YAML definition:

        jobTemplate:
          metadata:
            labels:
              app: heartbeat-cron
              bindings.knative.dev/include: "true"

   2. Create the cron job:

      $ oc apply -f <filename>

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

   $ kn source binding describe bind-heartbeat

   Example output

   Name:         bind-heartbeat
   Namespace:    demo-2
   Annotations:  sources.knative.dev/creator=minikube-user, sources.knative.dev/lastModifier=minikub ...
   Age:          2m
   Subject:
     Resource:   job (batch/v1)
     Selector:
       app:      heartbeat-cron
   Sink:
     Name:       event-display
     Resource:   Service (serving.knative.dev/v1)
   
   Conditions:
     OK TYPE     AGE REASON
     ++ Ready     2m

Procedure

1. Create a Knative service to use as a sink:

   1. Navigate to +Add YAML.

   2. Copy the example YAML:

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

   3. Click Create.

2. Create a CronJob resource that is used as an event source and sends an event every minute.

   1. Navigate to +Add YAML.

   2. Copy the example YAML:

      apiVersion: batch/v1
      kind: CronJob
      metadata:
        name: heartbeat-cron
      spec:
        # Run every minute
        schedule: "*/1 * * * *"
        jobTemplate:
          metadata:
            labels:
              app: heartbeat-cron
              bindings.knative.dev/include: true 

      1

      
          spec:
            template:
              spec:
                restartPolicy: Never
                containers:
                  - name: single-heartbeat
                    image: quay.io/openshift-knative/heartbeats
                    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

      Ensure that you include the bindings.knative.dev/include: true label. The default namespace selection behavior of OpenShift Serverless uses inclusion mode.

   3. Click Create.

3. Create a sink binding in the same namespace as the service created in the previous step, or any other sink that you want to send events to.

   1. Navigate to +Add Event Source. The Event Sources page is displayed.
   2. Optional: If you have multiple providers for your event sources, select the required provider from the Providers list to filter the available event sources from the provider.

   3. Select Sink Binding and then click Create Event Source. The Create Event Source page is displayed.

      注記

      You can configure the Sink Binding settings by using the Form view or YAML view and can switch between the views. The data is persisted when switching between the views.

   4. In the apiVersion field enter batch/v1.

   5. In the Kind field enter Job.

      注記

      The CronJob kind is not supported directly by OpenShift Serverless sink binding, so the Kind field must target the Job objects created by the cron job, rather than the cron job object itself.

   6. In the Target section, select your event sink. This can be either a Resource or a URI:

      1. Select Resource to use a channel, broker, or service as an event sink for the event source. In this example, the event-display service created in the previous step is used as the target Resource.
      2. Select URI to specify a Uniform Resource Identifier (URI) where the events are routed to.

   7. In the Match labels section:

      1. Enter app in the Name field.

      2. Enter heartbeat-cron in the Value field.

         注記

         The label selector is required when using cron jobs with sink binding, rather than the resource name. This is because jobs created by a cron job do not have a predictable name, and contain a randomly generated string in their name. For example, hearthbeat-cron-1cc23f.

   8. Click Create.

1. Navigate to Topology.

2. View the sink binding, sink, and heartbeats cron job.

   
3. Observe that successful jobs are being registered by the cron job once the sink binding is added. This means that the sink binding is successfully reconfiguring the jobs created by the cron job.

4. Browse the event-display service to see events produced by the heartbeats cron job.

   

Procedure

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

   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/showcase

   1

   A namespace that is a member of the ServiceMeshMemberRoll.

   2

   Injects Service Mesh sidecars into the Knative service pods.

2. Apply the Service resource.

   $ oc apply -f <filename>

3. Create a SinkBinding resource.

   apiVersion: sources.knative.dev/v1
   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 a member of the ServiceMeshMemberRoll.

   2

   In this example, any Job with the label app: heartbeat-cron is bound to the event sink.

4. Apply the SinkBinding resource.

   $ oc apply -f <filename>

5. Create a CronJob:

   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 a member of the ServiceMeshMemberRoll.

   2

   Injects Service Mesh sidecars into the CronJob pods.

6. Apply the CronJob resource.

   $ oc apply -f <filename>

1. Enter the following command:

   $ oc get pods

2. Enter the following 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/test/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": ""
     }

Procedure

1. Navigate to +Add Event Source. The Event Sources page is displayed.
2. Select Container Source and then click Create Event Source. The Create Event Source page is displayed.

3. Configure the Container Source settings by using the Form view or YAML view:

   注記

   You can switch between the Form view and YAML view. The data is persisted when switching between the views.

   1. In the Image field, enter the URI of the image that you want to run in the container created by the container source.
   2. In the Name field, enter the name of the image.
   3. Optional: In the Arguments field, enter any arguments to be passed to the container.
   4. Optional: In the Environment variables field, add any environment variables to set in the container.

   5. In the Target section, select your event sink. This can be either a Resource or a URI:

      1. Select Resource to use a channel, broker, or service as an event sink for the event source.
      2. Select URI to specify a Uniform Resource Identifier (URI) where the events are routed to.
4. After you have finished configuring the container source, click Create.

Procedure

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

   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/showcase

   1

   A namespace that is a member of the ServiceMeshMemberRoll.

   2

   Injects Service Mesh sidecars into the Knative service pods.

2. Apply the Service resource.

   $ oc apply -f <filename>

3. Create a ContainerSource object in a namespace that is a member of the ServiceMeshMemberRoll and sink set to the event-display.

   apiVersion: sources.knative.dev/v1
   kind: ContainerSource
   metadata:
     name: test-heartbeats
     namespace: <namespace> 

   1

   
   spec:
     template:
       metadata: 

   2

   
         annotations:
           sidecar.istio.io/inject: "true"
           sidecar.istio.io/rewriteAppHTTPProbers: "true"
       spec:
         containers:
           - image: quay.io/openshift-knative/heartbeats:latest
             name: heartbeats
             args:
               - --period=1s
             env:
               - name: POD_NAME
                 value: "example-pod"
               - name: POD_NAMESPACE
                 value: "event-test"
     sink:
       ref:
         apiVersion: serving.knative.dev/v1
         kind: Service
         name: event-display

   1

   A namespace is part of the ServiceMeshMemberRoll.

   2

   Enables Service Mesh integration with a ContainerSource object.

4. Apply the ContainerSource resource.

   $ oc apply -f <filename>

1. Enter the following command:

   $ oc get pods

2. Enter the following 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/test/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": ""
     }