Provide capability to push events to Event Grid Topic

[tomkerkhove]

Provide capability to push events to Event Grid Topic via an HTTP POST.

The only required aspect is an event type & body; but they can opt-in to specify the following:

• Event stamp (defaults to utc)
• Event subject (no default)
• Data version (defaults to 1)
• Event id (defaults to new guid)

Event Grid Configuration

The container is in charge of determining what Event Grid Topic it should forward the events to and how to authenticate.

This is done via environment variables on the container itself:

• ARCUS_EVENTGRID_TOPICENDPOINT - Endpoint of the topic
• ARCUS_EVENTGRID_AUTHKEY - Authentication key for the topic

This means that one container can only forward events to a single topic.

Configuration should be:

• Validated at startup
• Documented how to configure and what it represents

API Specification

• Verb: POST
• Path: api/v1/events/{event-type}
• Query parameters:
  • Event Id (optional, generated guid)
  • Event Stamp (optional, utc)
  • Subject (optional, empty by default)
  • Data version (optional, 1 by default)
• Reponse Body: None
• Response Headers:
  • X-Event-Id: Event-Id of emitted event
• Reponse Codes:
  • 200: Healthy
  • 503: Unhealthy

Depends on arcus-azure/arcus.eventgrid#57