Rebus.Datadog.Tracing

Description

A .Net Standard library containing 2 Rebus Steps that are used to be added in the Rebus pipeline as middlewares.

The 2 steps are:

• RebusSetTracingHeadersStep is an outgoing step that is used in the message producers to set the outgoing headers of the Rebus message. The headers are the 3 important headers used by Datadog
  

TraceId	SpanId (ParentId)	SamplingPriority
x-datadog-trace-id	x-datadog-parent-id	x-datadog-sampling-priority

• RebusLinkTracingHeaderStep is an incoming step used to fetch the headers set by the first step (RebusSetTracingHeadersStep) and creates a new trace using the 3 headers. If the TraceId is missing, the trace will no be created, if the other 2 headers are missing, the trace will still be created with the existing TraceId and a newly generated spanId, while SamplingPriority is set to null.

The current library only sets up tracing using Assembly Datadog.Trace version 2.2.0. If this library ends up to be useful, we will create one version for each corresponding Datadog.Trace version.

Usage example

Producer

.Options(o => o.Decorate<IPipeline>(c =>
			{
				var pipeline = c.Get<IPipeline>();
				var step = new RebusSetTracingHeadersStep(c.Get<IRebusLoggerFactory>());
				return new PipelineStepInjector(pipeline)
					.OnSend(step, PipelineRelativePosition.After, typeof(AssignDefaultHeadersStep));
			});

Consumer

.Options(o => o.Decorate<IPipeline>(c =>
			{
				var pipeline = c.Get<IPipeline>();
				var step = new RebusLinkTracingHeaderStep(c.Get<IRebusLoggerFactory>());
				return new PipelineStepInjector(pipeline)
					.OnReceive(step, PipelineRelativePosition.Before, typeof(DispatchIncomingMessageStep));
			});