Events in SlimFaas

SlimFaas supports a basic “publish/subscribe” model for broadcasting events to all replicas of a function. This can be used to trigger internal actions or notify your functions of certain events.

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1. Subscribe to Events

To allow a function to receive events, add the annotation SlimFaas/SubscribeEvents to the function's deployment:

metadata:
  annotations:
    SlimFaas/SubscribeEvents: "Public:my-event1,Private:my-event2,my-event3"

• Public events can be sent from any source.
• Private events can only be sent by trusted pods or within the same namespace.
• If you omit Public: or Private:, it defaults to SlimFaas/DefaultVisibility.

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2. Publishing an Event

Use the following HTTP route to publish an event:

• Endpoint: POST http://<slimfaas>/publish-event/<eventName>/<path>

• Body (any JSON payload):

{
  "data": "my-event-data"
}

• Response: 204 (No Content)

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3. Example

curl -X POST -H "Content-Type: application/json" \
     -d '{"data":"hello"}' \
     http://localhost:30021/publish-event/my-event-name/hello

All function replicas that have subscribed to my-event-name will receive a POST request at their /hello URL (e.g., http://<pod_ip>:<pod_port>/hello), and can handle it as needed.