11.3. Using the API server source

Procedure

1. Create a service account, role, and role binding for the event source by creating a file named authentication.yaml and copying the following sample code into it:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: events-sa
     namespace: default 

   1

   
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: Role
   metadata:
     name: event-watcher
     namespace: default 

   2

   
   rules:
     - apiGroups:
         - ""
       resources:
         - events
       verbs:
         - get
         - list
         - watch
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: k8s-ra-event-watcher
     namespace: default 

   3

   
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: Role
     name: event-watcher
   subjects:
     - kind: ServiceAccount
       name: events-sa
       namespace: default 

   4

   Copy to Clipboard Toggle word wrap

   1 2 3 4

   Change this namespace to the namespace that you have selected for installing the event source.

   注意

   If you want to re-use an existing service account with the appropriate permissions, you must modify the authentication.yaml for that service account.

2. Create the service account, role binding, and cluster binding by entering the following command:

   $ oc apply --filename authentication.yaml

   Copy to Clipboard Toggle word wrap

Procedure

1. Navigate to the Add page and select Event Source.

2. In the Event Sources page, select ApiServerSource in the Type section.

   

   View larger image

   

3. Configure the ApiServerSource settings:

   1. Enter v1 as the APIVERSION, and Event as the KIND.

   2. Select the Service Account Name for the service account that you created.

      

      View larger image

      
   3. Select the targeted Knative service from the dropdown menu in Sink Knative Service.
4. Click Create.

Verification

1. After you have created the ApiServerSource, you will see it connected to the service it is sinked to in the Topology view.

   

   View larger image

   

Procedure

1. Navigate to the Topology view.

2. Right-click the ApiServerSource and select Delete ApiServerSource.

   

   View larger image

   

Procedure

1. Create a service account, role, and role binding for the ApiServerSource object.

   You can do this by creating a file named authentication.yaml and copying the following sample code into it:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: events-sa
     namespace: default 

   1

   
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: Role
   metadata:
     name: event-watcher
     namespace: default 

   2

   
   rules:
     - apiGroups:
         - ""
       resources:
         - events
       verbs:
         - get
         - list
         - watch
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: k8s-ra-event-watcher
     namespace: default 

   3

   
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: Role
     name: event-watcher
   subjects:
     - kind: ServiceAccount
       name: events-sa
       namespace: default 

   4

   Copy to Clipboard Toggle word wrap

   1 2 3 4

   Change this namespace to the namespace that you have selected for installing the API server source.

   注意

   If you want to reuse an existing service account with the appropriate permissions, you must modify the authentication.yaml file for that service account.

   Create the service account, role binding, and cluster binding:

   $ oc apply -f authentication.yaml

   Copy to Clipboard Toggle word wrap

2. Create an ApiServerSource object that uses a broker as an event sink:

   $ kn source apiserver create <event_source_name> --sink broker:<broker_name> --resource "event:v1" --service-account <service_account_name> --mode Resource

   Copy to Clipboard Toggle word wrap

3. Create a Knative service that dumps incoming messages to its log:

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

   Copy to Clipboard Toggle word wrap

4. Create a trigger to filter events from the default broker to the service:

   $ kn trigger create <trigger_name> --sink ksvc:<service_name>

   Copy to Clipboard Toggle word wrap

5. Create events by launching a pod in the default namespace:

   $ oc create deployment hello-node --image=quay.io/openshift-knative/knative-eventing-sources-event-display

   Copy to Clipboard Toggle word wrap

6. Check that the controller is mapped correctly by inspecting the output generated by the following command:

   $ kn source apiserver describe testevents

   Copy to Clipboard Toggle word wrap

   Example output

   Name:                testevents
   Namespace:           default
   Annotations:         sources.knative.dev/creator=developer, sources.knative.dev/lastModifier=developer
   Age:                 3m
   ServiceAccountName:  events-sa
   Mode:                Resource
   Sink:
     Name:       default
     Namespace:  default
     Kind:       Broker (eventing.knative.dev/v1)
   Resources:
     Kind:        event (v1)
     Controller:  false
   Conditions:
     OK TYPE                     AGE REASON
     ++ Ready                     3m
     ++ Deployed                  3m
     ++ SinkProvided              3m
     ++ SufficientPermissions     3m
     ++ EventTypesProvided        3m

   Copy to Clipboard Toggle word wrap

1. Get the pods:

   $ oc get pods

   Copy to Clipboard Toggle word wrap

2. View the message dumper function logs for the pods:

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

   Copy to Clipboard Toggle word wrap

   Example output

   ☁️  cloudevents.Event
   Validation: valid
   Context Attributes,
     specversion: 1.0
     type: dev.knative.apiserver.resource.update
     datacontenttype: application/json
     ...
   Data,
     {
       "apiVersion": "v1",
       "involvedObject": {
         "apiVersion": "v1",
         "fieldPath": "spec.containers{hello-node}",
         "kind": "Pod",
         "name": "hello-node",
         "namespace": "default",
          .....
       },
       "kind": "Event",
       "message": "Started container",
       "metadata": {
         "name": "hello-node.159d7608e3a3572c",
         "namespace": "default",
         ....
       },
       "reason": "Started",
       ...
     }

   Copy to Clipboard Toggle word wrap

Procedure

1. Delete the trigger:

   $ kn trigger delete <trigger_name>

   Copy to Clipboard Toggle word wrap

2. Delete the service:

   $ kn service delete <service_name>

   Copy to Clipboard Toggle word wrap

3. Delete the API server source:

   $ kn source apiserver delete <source_name>

   Copy to Clipboard Toggle word wrap
4. Delete the service account, cluster role, and cluster binding:

Procedure

1. To create a service account, role, and role binding for the API server source, create a file named authentication.yaml and copy the following sample code into it:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: events-sa
     namespace: default 

   1

   
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: Role
   metadata:
     name: event-watcher
     namespace: default 

   2

   
   rules:
     - apiGroups:
         - ""
       resources:
         - events
       verbs:
         - get
         - list
         - watch
   
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: k8s-ra-event-watcher
     namespace: default 

   3

   
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: Role
     name: event-watcher
   subjects:
     - kind: ServiceAccount
       name: events-sa
       namespace: default 

   4

   Copy to Clipboard Toggle word wrap

   1 2 3 4

   Change this namespace to the namespace that you have selected for installing the API server source.

   注意

   If you want to re-use an existing service account with the appropriate permissions, you must modify the authentication.yaml for that service account.

   After you have created the authentication.yaml file, apply it:

   $ oc apply -f authentication.yaml

   Copy to Clipboard Toggle word wrap

2. To create an ApiServerSource object, create a file named k8s-events.yaml and copy the following sample code into it:

   apiVersion: sources.knative.dev/v1alpha1
   kind: ApiServerSource
   metadata:
     name: testevents
   spec:
     serviceAccountName: events-sa
     mode: Resource
     resources:
       - apiVersion: v1
         kind: Event
     sink:
       ref:
         apiVersion: eventing.knative.dev/v1
         kind: Broker
         name: default

   Copy to Clipboard Toggle word wrap

   After you have created the k8s-events.yaml file, apply it:

   $ oc apply -f k8s-events.yaml

   Copy to Clipboard Toggle word wrap

3. To check that the API server source is set up correctly, create a Knative service that dumps incoming messages to its log.

   Copy the following sample YAML into a file named service.yaml:

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

   Copy to Clipboard Toggle word wrap

   After you have created the service.yaml file, apply it:

   $ oc apply -f service.yaml

   Copy to Clipboard Toggle word wrap

4. To create a trigger from the default broker that filters events to the service created in the previous step, create a file named trigger.yaml and copy the following sample code into it:

   apiVersion: eventing.knative.dev/v1
   kind: Trigger
   metadata:
     name: event-display-trigger
     namespace: default
   spec:
     broker: default
     subscriber:
       ref:
         apiVersion: serving.knative.dev/v1
         kind: Service
         name: event-display

   Copy to Clipboard Toggle word wrap

   After you have created the trigger.yaml file, apply it:

   $ oc apply -f trigger.yaml

   Copy to Clipboard Toggle word wrap

5. To create events, launch a pod in the default namespace:

   $ oc create deployment hello-node --image=quay.io/openshift-knative/knative-eventing-sources-event-display

   Copy to Clipboard Toggle word wrap

6. To check that the controller is mapped correctly, enter the following command and inspect the output:

   $ oc get apiserversource.sources.knative.dev testevents -o yaml

   Copy to Clipboard Toggle word wrap

   Example output

   apiVersion: sources.knative.dev/v1alpha1
   kind: ApiServerSource
   metadata:
     annotations:
     creationTimestamp: "2020-04-07T17:24:54Z"
     generation: 1
     name: testevents
     namespace: default
     resourceVersion: "62868"
     selfLink: /apis/sources.knative.dev/v1alpha1/namespaces/default/apiserversources/testevents2
     uid: 1603d863-bb06-4d1c-b371-f580b4db99fa
   spec:
     mode: Resource
     resources:
     - apiVersion: v1
       controller: false
       controllerSelector:
         apiVersion: ""
         kind: ""
         name: ""
         uid: ""
       kind: Event
       labelSelector: {}
     serviceAccountName: events-sa
     sink:
       ref:
         apiVersion: eventing.knative.dev/v1
         kind: Broker
         name: default

   Copy to Clipboard Toggle word wrap

1. Get the pods:

   $ oc get pods

   Copy to Clipboard Toggle word wrap

2. View the message dumper function logs for the pods:

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

   Copy to Clipboard Toggle word wrap

   Example output

   ☁️  cloudevents.Event
   Validation: valid
   Context Attributes,
     specversion: 1.0
     type: dev.knative.apiserver.resource.update
     datacontenttype: application/json
     ...
   Data,
     {
       "apiVersion": "v1",
       "involvedObject": {
         "apiVersion": "v1",
         "fieldPath": "spec.containers{hello-node}",
         "kind": "Pod",
         "name": "hello-node",
         "namespace": "default",
          .....
       },
       "kind": "Event",
       "message": "Started container",
       "metadata": {
         "name": "hello-node.159d7608e3a3572c",
         "namespace": "default",
         ....
       },
       "reason": "Started",
       ...
     }

   Copy to Clipboard Toggle word wrap

Procedure

1. Delete the trigger:

   $ oc delete -f trigger.yaml

   Copy to Clipboard Toggle word wrap

2. Delete the service:

   $ oc delete -f service.yaml

   Copy to Clipboard Toggle word wrap

3. Delete the API server source:

   $ oc delete -f k8s-events.yaml

   Copy to Clipboard Toggle word wrap

4. Delete the service account, cluster role, and cluster binding:

   $ oc delete -f authentication.yaml

   Copy to Clipboard Toggle word wrap