public void Start()
{
if (_allListenersSubscription == null)
{
if (_tracer.IsNoopTracer() && !_options.StartInstrumentationForNoopTracer)
{
_logger.LogWarning("Instrumentation has not been started because no tracer was registered.");
}
else
{
_logger.LogTrace("Starting AllListeners subscription");
_allListenersSubscription = DiagnosticListener.AllListeners.Subscribe(this);
}
}
}
public void Emit(LogEvent logEvent)
{
ISpan span = _tracer.ActiveSpan;
if (span == null)
{
// Creating a new span for a log message seems brutal so we ignore messages if we can't attach it to an active span.
return;
}
if (_tracer.IsNoopTracer())
{
return;
}
if (_filter(logEvent))
{
return;
}
var fields = new Dictionary <string, object>();
try
{
fields[LogFields.Event] = "log";
fields[LogFields.Message] = logEvent.RenderMessage();
fields["level"] = logEvent.Level;
if (logEvent.Exception != null)
{
fields[LogFields.ErrorKind] = logEvent.Exception.GetType().FullName;
fields[LogFields.ErrorObject] = logEvent.Exception;
}
foreach (var property in logEvent.Properties)
{
fields[property.Key] = property.Value.ToString();
}
}
catch (Exception logException)
{
fields["opentracing.contrib.netcore.error"] = logException.ToString();
}
span.Log(fields);
}