Fabric API - Events

An eventstream's custom endpoint accepts Kafka and REST clients, so the connections below are Zato's Kafka and REST connections configured for Fabric. The events page uses them in services. Eventhouses are queried with the Fabric connection's query_events.

Where the values come from

All values on this page come from the Details pane of the eventstream's custom endpoint, on the SAS Key Authentication page of its Kafka tab, whether the endpoint is a source (Zato sends) or a destination (Zato receives):

The namespace is the first part of the bootstrap server, up to .servicebus.windows.net.

Security definitions

Two kinds of definition sign a Kafka connection in, and both are created under Security in the Dashboard:

The username is entered as $$ConnectionString because a value starting with a single $ names an environment variable, and doubling it gives the literal $ConnectionString.

An environment holds one Bearer token definition per client ID, so the Kafka scope and the REST scope each sign in as an app registration of their own, added to the workspace as a Contributor.

Kafka outgoing connection

Under Connections → Message queues → Kafka → Outgoing connections:

outgoing_kafka:
  - name: Fabric Events
    address: <namespace>.servicebus.windows.net:9093
    topic: <topic name>
    security: Fabric Events Token
    sasl_mechanism: OAUTHBEARER
    ssl: true

A dict passed to send is JSON-encoded before it leaves:

event = {
    'event_type': 'admission',
    'location': 'Riverside',
    'admission_id': 'ADM-1041',
}

self.out.kafka['Fabric Events'].send(event)

Kafka channel

Under Connections → Message queues → Kafka → Channels:

channel_kafka:
  - name: Fabric Alerts
    address: <namespace>.servicebus.windows.net:9093
    topic: <topic name>
    group_id: zato
    service: fabric.notify-purchasing
    security: Fabric Events Token
    sasl_mechanism: OAUTHBEARER
    ssl: true

The eventstream sends events in batches, as a JSON list, which the service receives parsed in self.request.input:

for event in self.request.input:
    item_id = event['item_id']

REST alternative for sending

The same endpoint also takes events over HTTPS. Under Connections → REST → Outgoing connections:

The body is a list of events, each wrapped in Body, sent with the endpoint's own content type:

body = json.dumps(event)
payload = [{'Body': body}]
headers = {'Content-Type': 'application/vnd.microsoft.servicebus.json'}

self.rest['Fabric Events REST'].post(payload, headers=headers)

See also

Learn more