Client connection, channels, queues, consumers, and other parts of the system naturally generate events. For example, when a connection is accepted, authenticated and access to the target virtual host is authorised, it will emit an event of type
connection_created. When a connection is closed or fails for any reason, a
connection_closed event is emitted.
Monitoring and auditing services can be interested in observing those events. RabbitMQ has a minimalistic mechanism for event notifications that can be exposed to RabbitMQ clients with a plugin.
rabbitmq-event-exchange is a plugin that consumes internal events and re-publishes them to a topic exchange, thus exposing the events to clients (applications).
To consume the events, an application needs to declare a queue, bind it to a special system exchange and consume messages.
It declares a topic exchange called
amq.rabbitmq.event in the default virtual host. All events are published to this exchange with routing keys like 'exchange.created', 'binding.deleted' etc, so you can subscribe to only the events you're interested in.
The exchange behaves similarly to
amq.rabbitmq.log: everything gets published there; if you don't trust a user with the information that gets published, don't allow them access.
The plugin requires no configuration, just activate it:
rabbitmq-plugins enable rabbitmq_event_exchange
Each event has various properties associated with it. These are translated into AMQP 0-9-1 data encoding and inserted in the message headers. The message body is always blank.
RabbitMQ and related plugins produce events with the following routing keys:
Queue, Exchange and Binding events:
Connection and Channel events:
Policy and Parameter events:
Virtual host events:
User related events:
There is a usage example using the Java client in the rabbitmq-event-exchange repository.