public string SendMessage()
{
try
{
// Start an activity with a name following the semantic convention of the OpenTelemetry messaging specification.
// https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/semantic_conventions/messaging.md#span-name
var activityName = $"{RabbitMqHelper.TestQueueName} send";
using (var activity = ActivitySource.StartActivity(activityName, ActivityKind.Producer))
{
var props = this.channel.CreateBasicProperties();
// Depending on Sampling (and whether a listener is registered or not), the
// activity above may not be created.
// If it is created, then propagate its context.
// If it is not created, the propagate the Current context,
// if any.
ActivityContext contextToInject = default;
if (activity != null)
{
contextToInject = activity.Context;
}
else if (Activity.Current != null)
{
contextToInject = Activity.Current.Context;
}
// Inject the ActivityContext into the message headers to propagate trace context to the receiving service.
Propagator.Inject(new PropagationContext(contextToInject, Baggage.Current), props, this.InjectTraceContextIntoBasicProperties);
// The OpenTelemetry messaging specification defines a number of attributes. These attributes are added here.
RabbitMqHelper.AddMessagingTags(activity);
var body = $"Published message: DateTime.Now = {DateTime.Now}.";
this.channel.BasicPublish(
exchange: RabbitMqHelper.DefaultExchangeName,
routingKey: RabbitMqHelper.TestQueueName,
basicProperties: props,
body: Encoding.UTF8.GetBytes(body));
this.logger.LogInformation($"Message sent: [{body}]");
return(body);
}
}
catch (Exception ex)
{
this.logger.LogError(ex, "Message publishing failed.");
throw;
}
}
public MessageSender(ILogger <MessageSender> logger)
{
this.logger = logger;
this.connection = RabbitMqHelper.CreateConnection();
this.channel = RabbitMqHelper.CreateModelAndDeclareTestQueue(this.connection);
}