APIServerSource

    An APIServerSource brings Kubernetes API server events into Knative.

    The APIServerSource source type is enabled by default when you install Knative Eventing.

    This example shows how to create an APIServerSource that listens to Kubernetes Events and send CloudEvents to the Event Display Service.

    Create a new namespace called by entering the following command:

    Creating the Event Display Service

    To deploy the event-display consumer to your cluster, run the following command:

    1. kubectl -n apiserversource-example apply -f - << EOF
    2. apiVersion: apps/v1
    3. kind: Deployment
    4. metadata:
    5.   name: event-display
    6. spec:
    7.   replicas: 1
    8.   selector:
    9.     matchLabels: &labels
    10.       app: event-display
    11.   template:
    12.     metadata:
    13.       labels: *labels
    14.     spec:
    15.       containers:
    16.         - name: event-display
    17.           image: gcr.io/knative-releases/knative.dev/eventing-contrib/cmd/event_display
    19. ---
    21. kind: Service
    22. apiVersion: v1
    23. metadata:
    24.   name: event-display
    25. spec:
    26.   selector:
    27.     app: event-display
    28.   ports:
    29.   - protocol: TCP
    30.     port: 80
    31.     targetPort: 8080
    32. EOF

    Create a Service Account that the ApiServerSource runs as. The ApiServerSource watches for Kubernetes events and forwards them to the Knative Eventing Broker.

    1. kubectl -n apiserversource-example apply -f - << EOF
    2. apiVersion: v1
    3. metadata:
    4.  name: events-sa
    5.  namespace: apiserversource-example
    7. ---
    8. apiVersion: rbac.authorization.k8s.io/v1
    9. kind: ClusterRole
    10. metadata:
    11.  name: event-watcher
    12. rules:
    13.  - apiGroups:
    14.      - ""
    15.    resources:
    16.      - events
    17.    verbs:
    18.      - get
    19.      - list
    20.      - watch
    22. ---
    23. apiVersion: rbac.authorization.k8s.io/v1
    24. kind: ClusterRoleBinding
    25. metadata:
    26.  name: k8s-ra-event-watcher
    27. roleRef:
    28.  apiGroup: rbac.authorization.k8s.io
    29.  kind: ClusterRole
    30.  name: event-watcher
    31. subjects:
    32.  - kind: ServiceAccount
    33.    name: events-sa
    34.    namespace: apiserversource-example
    35. EOF

    Creating the APIServerSource

    In order to receive kubernetes events, you need to create a concrete APIServerSource for the namespace.

    1. kn source apiserver create testevents \
    2.   --namespace apiserversource-example \
    3.   --mode "Resource" \
    4.   --resource "Event:v1" \
    5.   --service-account events-sa \
    6.   --sink  --sink http://event-display.svc.cluster.local

    Create events by launching a pod in the default namespace. Create a busybox container and immediately delete it:

    1. kubectl -n apiserversource-example run busybox --image=busybox --restart=Never -- ls
    2. kubectl -n apiserversource-example delete pod busybox

    Verify

    You should see log lines similar to:

    1. ☁️  cloudevents.Event
    2. Validation: valid
    3.   specversion: 1.0
    4.   type: dev.knative.apiserver.resource.update
    6.   subject: /apis/v1/namespaces/apiserversource-example/events/testevents.15dd3050eb1e6f50
    7.   id: e0447eb7-36b5-443b-9d37-faf4fe5c62f0
    8.   time: 2020-07-28T19:14:54.719501054Z
    9.   datacontenttype: application/json
    10. Extensions,
    11.   kind: Event
    12.   name: busybox.1626008649e617e3
    13.   namespace: apiserversource-example
    14. Data,
    15.   {
    16.     "apiVersion": "v1",
    17.     "count": 1,
    18.     "eventTime": null,
    19.     "firstTimestamp": "2020-07-28T19:14:54Z",
    20.     "involvedObject": {
    21.       "apiVersion": "v1",
    22.       "fieldPath": "spec.containers{busybox}",
    23.       "kind": "Pod",
    24.       "name": "busybox",
    25.       "namespace": "apiserversource-example",
    26.       "resourceVersion": "28987493",
    27.       "uid": "1efb342a-737b-11e9-a6c5-42010a8a00ed"
    28.     },
    29.     "kind": "Event",
    30.     "lastTimestamp": "2020-07-28T19:14:54Z",
    31.     "message": "Started container",
    32.     "metadata": {
    33.       "creationTimestamp": "2020-07-28T19:14:54Z",
    34.       "name": "busybox.1626008649e617e3",
    35.       "namespace": "default",
    36.       "resourceVersion": "506088",
    37.     "selfLink": "/api/v1/namespaces/apiserversource-example/events/busybox.1626008649e617e3",
    38.       "uid": "2005af47-737b-11e9-a6c5-42010a8a00ed"
    39.     },
    40.     "reason": "Started",
    41.     "reportingComponent": "",
    42.     "reportingInstance": "",
    43.     "source": {
    44.       "component": "kubelet",
    45.       "host": "gke-knative-auto-cluster-default-pool-23c23c4f-xdj0"
    46.     },
    47.     "type": "Normal"

    Delete the namespace and all of its resources from your cluster by entering the following command:

    1. kubectl delete namespace apiserversource-example

    See the .

    For any inquiries about this source, please reach out on to the Knative users group.