openshift-docs/modules/apiserversource-yaml.adoc

// Module included in the following assemblies:
//
// serverless/event_workflows/serverless-listing-event-sources.adoc

[id="apiserversource-yaml_context"]
= Using the ApiServerSource with the YAML method

This guide describes the steps required to create an ApiServerSource using YAML files.

.Prerequisites

* You will need to have a Knative Serving and Eventing installation.
* You will need to have created the `default` broker in the same namespace as the one defined in the ApiServerSource YAML file.

.Procedure

. To create a service account, role, and role binding for the ApiServerSource, create a file named `authentication.yaml` and copy the following sample code into it:
+
[source,yaml]
----
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 <1>
rules:
  - apiGroups:
      - ""
    resources:
      - events
    verbs:
      - get
      - list
      - watch

---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: k8s-ra-event-watcher
  namespace: default <1>
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: event-watcher
subjects:
  - kind: ServiceAccount
    name: events-sa
    namespace: default <1>
----
+
<1> Change this namespace to the namespace that you have selected for installing ApiServerSource.
+
[NOTE]
====
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:
+
[source,terminal]
----
$ oc apply -f authentication.yaml
----

. To create an ApiServerSource event source, create a file named `k8s-events.yaml` and copy the following sample code into it:
+
[source,yaml]
----
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
----

+
After you have created the `k8s-events.yaml` file, apply it:
+
[source,terminal]
----
$ oc apply -f k8s-events.yaml
----

. To check that the ApiServerSource 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`:
+
[source,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
----
+
After you have created the `service.yaml` file, apply it:
+
[source,terminal]
----
$ oc apply -f service.yaml
----

. 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:
+
[source,yaml]
----
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
----
+
After you have created the `trigger.yaml` file, apply it:
+
[source,terminal]
----
$ oc apply -f trigger.yaml
----

. To create events, launch a Pod in the default namespace:
+
[source,terminal]
----
$ oc create deployment hello-node --image=quay.io/openshift-knative/knative-eventing-sources-event-display
----

. To check that the controller is mapped correctly, enter the following command and inspect the output:
+
[source,terminal]
----
$ oc get apiserversource.sources.knative.dev testevents -o yaml
----
+
.Example output
+
[source,yaml]
----
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
----

.Verification steps

To verify that the Kubernetes events were sent to Knative, you can look at the message dumper function logs.

. Get the pods:
+
[source,terminal]
----
$ oc get pods
----

. View the message dumper function logs for the pods:
+
[source,terminal]
----
$ oc logs $(oc get pod -o name | grep event-display) -c user-container
----
+
.Example output
+
[source,terminal]
----
☁️  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",
    ...
  }
----