Cron job source example

Cron Job Source example shows how to configure Cron Job as event source for functions.

Deployment Steps

Prerequisites

  1. Setup Knative Serving.
  2. Setup Knative Eventing.

Create a Knative Service

In order to verify CronJobSource is working, we will create a simple Knative Service that dumps incoming messages to its log.

apiVersion: serving.knative.dev/v1alpha1
kind: Service
metadata:
  name: message-dumper
spec:
  runLatest:
    configuration:
      revisionTemplate:
        spec:
          container:
            image: gcr.io/knative-releases/github.com/knative/eventing-sources/cmd/message_dumper

Use following command to create the service from service.yaml:

kubectl apply -f service.yaml

Create Cron Job Event Source

For each set of cron events you want to request, you need to create an Event Source in the same namespace as the destiantion. If you need a different ServiceAccount to create the Deployment, modify the entry accordingly in the yaml.

apiVersion: sources.eventing.knative.dev/v1alpha1
kind: CronJobSource
metadata:
  name: test-cronjob-source
spec:
  schedule: "*/2 * * * *"
  data: '{"message": "Hello world!"}'
  sink:
    apiVersion: serving.knative.dev/v1alpha1
    kind: Service
    name: message-dumper

Use following command to create the event source from cronjob-source.yaml:

kubectl apply -f cronjob-source.yaml

Verify

We will verify that the message was sent to the Knative eventing system by looking at message dumper logs.

  1. Use kail to tail the logs of the subscriber.
   kail -l serving.knative.dev/service=message-dumper -c user-container --since=10m

You should see log lines showing the request headers and body from the source:

{
  "ID": "1543616460000180552-203",
  "EventTime": "2018-11-30T22:21:00.000186721Z",
  "Body": "{\"message\": \"Hello world!\"}"
}