amqptracer

Documentation

Overview

Package amqptracer provides OpenTracing instrumentation for the github.com/streadway/amqp package.

Index

• func Extract(hdrs amqp.Table) (opentracing.SpanContext, error)
• func Inject(span opentracing.Span, hdrs amqp.Table) error

Functions

func Extract

func Extract(hdrs amqp.Table) (opentracing.SpanContext, error)

Extract extracts the span context out of the AMQP header.

Example:

func ConsumeMessage(ctx context.Context, msg *amqp.Delivery) error {
	// Extract the span context out of the AMQP header.
	spCtx, _ := amqptracer.Extract(msg.Headers)
	sp := opentracing.StartSpan(
		"ConsumeMessage",
		opentracing.FollowsFrom(spCtx),
	)
	defer sp.Finish()

	// Update the context with the span for the subsequent reference.
	ctx = opentracing.ContextWithSpan(ctx, sp)

	// Actual message processing.
	return ProcessMessage(ctx, msg)
}

func Inject

func Inject(span opentracing.Span, hdrs amqp.Table) error

Inject injects the span context into the AMQP header.

Example:

func PublishMessage(
	ctx context.Context,
	ch *amqp.Channel,
	exchange, key string,
	mandatory, immediate bool,
	msg *amqp.Publishing,
) error {
	sp := opentracing.SpanFromContext(ctx)
	defer sp.Finish()

	// Inject the span context into the AMQP header.
	if err := amqptracer.Inject(sp, msg.Headers); err != nil {
		return err
	}

	// Publish the message with the span context.
	return ch.Publish(exchange, key, mandatory, immediate, msg)
}