Gateway integration with RabbitMQ consumers

Document updated on Jan 24, 2022

The AMQP component allows to send and receive messages to and from a queue through the API Gateway.

The configuration of the queue is a straightforward process. To connect the endpoints to the messaging system you only need to include the extra_config key with the namespaces backend/amqp/consumer or backend/amqp/producer.

To create Async agents that consume messages asynchronously and without requiring a user request, see Async Agents.

The parameters of this integration follow the AMQP specification. To understand what are the implications of a certain parameter, see the AMQP Complete Reference Guide.

KrakenD creates both the exchange and the queue for you.

Configuration

The consumer retrieves messages from the queue when a KrakenD endpoint plugs to its AMQP backend. The recommendation is to connect consumers to GET endpoints.

A single endpoint can consume messages from N queues, or can consume N messages from the same queue by adding N backends with the proper queue name.

See Async Agents to consume messages without an endpoint.

The needed configuration to run a consumer is:

{
    "backend": [{
        "host": ["amqp://guest:[email protected]:5672"],
        "disable_host_sanitize": true,
        "extra_config": {
            "backend/amqp/consumer": {
                "name": "queue-1",
                "exchange": "some-exchange",
                "durable": true,
                "delete": false,
                "no_wait": true,
                "no_local": false,
                "routing_key": ["#"],
                "prefetch_count": 10,
                "prefetch_size": 1024,
                "auto_ack": false
            }
        }
    }]
}