Publish from RabbitMQ
This guide provides information on using RabbitMQ to publish events to Outpost.
Message Structure
RabbitMQ messages should have the same payload structure as the Publish API endpoint.
{
"tenant_id": "<TENANT_ID>",
"destination_id": "<DESTINATION_ID>", // Optional. Provide a way of routing events to a specific destination
"topic": "topic.name", // Topic defined in TOPICS environment variable
"eligible_for_retry": true | false, // Should event delivery be retried? Default is true.
"metadata": Payload, // can be any JSON payload,
"data": Payload // can be any JSON payload
}
Configuration
Provide Outpost with connection and routing information for your RabbitMQ instance used for publishing events.
Environment Variables
PUBLISH_RABBITMQ_SERVER_URL="<SERVER_URL>"
PUBLISH_RABBITMQ_EXCHANGE="<EXCHANGE_NAME>"
PUBLISH_RABBITMQ_QUEUE="<QUEUE_NAME>"
Example
PUBLISH_RABBITMQ_SERVER_URL="amqp://guest:guest@localhost:5673"
PUBLISH_RABBITMQ_EXCHANGE="outpost"
PUBLISH_RABBITMQ_QUEUE="publish"
YAML
publishmq:
publishmq:
rabbitmq:
server_url: <SERVER_URL>
exchange: <EXCHANGE_NAME>
queue: <QUEUE_NAME>
Example
publishmq:
rabbitmq:
server_url: amqp://guest:guest@localhost:5673
exchange: outpost
queue: publish
Connecting through a proxy
If your broker only accepts connections from allowlisted IPs, set PUBLISH_PROXY_URL (YAML: publishmq.proxy_url) to route the publish queue connection through an HTTP forward proxy with a static egress IP, then allowlist that IP on the broker.
PUBLISH_PROXY_URL="http://user:pass@proxy.example.com:8080"
Outpost opens an HTTP CONNECT tunnel through the proxy to the broker's host and port and runs AMQP inside it. With amqps://, TLS is negotiated with the broker end to end through the tunnel, so the proxy never sees message contents or broker credentials. Multiple whitespace-separated proxy URLs are tunneled in order, nearest first; the broker sees the connection coming from the last one. Each hop may carry its own basic auth credentials.
The proxy must allow CONNECT to the broker's port (5672 for amqp, 5671 for amqps by default). Any idle timeout on the proxy must be longer than the AMQP heartbeat interval (10 seconds unless the server URL sets heartbeat). The Webhook Forward Proxy guide has a reference Envoy configuration that works for both.
PUBLISH_PROXY_URL applies to the RabbitMQ publish queue only. AWS SQS, GCP Pub/Sub and Azure Service Bus publish queues connect directly and ignore it, and it never applies to Outpost's internal delivery and log queues.