OpenTelemetry with RabbitMQ add messaging.rabbitmq.destination.routing_key from the semantic convention

[vmeunier]

Expected Behavior

There are several fields in the semantic convention for RabbitMQ and RabbitTemplate is missing the one named messaging.rabbitmq.destination.routing_key.

Current Behavior

At the moment, in RabbitTemplate, the observationContext concatenates "exchange/routingKey" in the field messaging.destination.name

Context

If we want to be fully "OpenTelemetry compliant" then we should use all the fields we can with the information we have.
IMO it is a mistake to concatenate two different strings in one, it makes the research or filtering in traces/metrics afterwards more complicated.

messaging.destination.name must be the name of the exchange
messaging.rabbitmq.destination.routing_key must be the name of the routingKey

In RabbitMQ, the destination is defined by an exchange and a routing key. messaging.destination.name MUST be set to the name of the exchange. This will be an empty string if the default exchange is used.

EDIT :

We can also add somes tags for RabbitListenerObservationConvention :
messaging.destination.name which will be the consumerQueue
messaging.rabbitmq.message.delivery_tag the delivery tag of the message being processed

[artembilan]

We do not follow those conventions by default because of Status: Experimental.
However additional tags to whatever we have chosen by default would not harm.
In fact we had similar contribution in the past into Spring for Apache Kafka: spring-projects/spring-kafka#2609.

So, feel free to raise respective PR and we will be more than happy to review and merge!

[vmeunier]

Ok, i'll try to send you a PR :)