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Script filter

Script filters can be used to filter the events with LUA scripts.

Script filters are applied to the event data. A CloudEvent from Webhook event-source has payload structure as:

  "context": {
    "type": "type_of_event_source",
    "specversion": "cloud_events_version",
    "source": "name_of_the_event_source",
    "id": "unique_event_id",
    "time": "event_time",
    "datacontenttype": "type_of_data",
    "subject": "name_of_the_configuration_within_event_source"
  "data": {
    "header": {},
    "body": {}


An Script filter can be defined under filters with a field script:

  script: |-
    if event.body.a == "b" and event.body.d.e == "z" then return true else return false end

Practical example

  1. Create a webhook event-source

    kubectl -n argo-events apply -f
  2. Create a webhook sensor with context filter

    kubectl -n argo-events apply -f
  3. Send an HTTP request to the event-source

    kubectl port-forward svc/webhook-eventsource-svc 12000
    curl -d '{"hello": "world"}' -X POST http://localhost:12000/example
  4. You will notice in sensor logs that the event did not trigger anything.

  5. Send another HTTP request the event-source

    curl -X POST -d '{"a": "b", "d": {"e": "z"}}' http://localhost:12000/example
  6. Then you will see the event successfully triggered a workflow creation.

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