Pass the GlobalTracerAccessor into OpenTracingLogger so that the NoopTracer is not cached when the tracer hasn't been configured yet and logger providers are resolved. (#50)

Author: yelob

src/OpenTracing.Contrib.NetCore/Logging/OpenTracingLogger.cs

@@ -2,19 +2,21 @@
 using System.Collections.Generic;
 using Microsoft.Extensions.Logging;
 using OpenTracing.Contrib.NetCore.Internal;
+using OpenTracing.Noop;
+using OpenTracing.Util;
 
 namespace OpenTracing.Contrib.NetCore.Logging
 {
     internal class OpenTracingLogger : ILogger
     {
         private const string OriginalFormatPropertyName = "{OriginalFormat}";
 
-        private readonly ITracer _tracer;
         private readonly string _categoryName;
+        private readonly IGlobalTracerAccessor _globalTracerAccessor;
 
-        public OpenTracingLogger(ITracer tracer, string categoryName)
+        public OpenTracingLogger(IGlobalTracerAccessor globalTracerAccessor, string categoryName)
         {
-            _tracer = tracer;
+            _globalTracerAccessor = globalTracerAccessor;
             _categoryName = categoryName;
         }
 
@@ -26,8 +28,10 @@ public IDisposable BeginScope<TState>(TState state)
         public bool IsEnabled(LogLevel logLevel)
         {
             // Filtering should be done via the general Logging filtering feature.
-
-            return !_tracer.IsNoopTracer();
+            ITracer tracer = _globalTracerAccessor.GetGlobalTracer();
+            return !(
+                (tracer is NoopTracer) ||
+                (tracer is GlobalTracer && !GlobalTracer.IsRegistered()));
         }
 
         public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
@@ -38,7 +42,8 @@ public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Except
                 return;
             }
 
-            ISpan span = _tracer.ActiveSpan;
+            ITracer tracer = _globalTracerAccessor.GetGlobalTracer();
+            ISpan span = tracer.ActiveSpan;
 
             if (span == null)
             {

src/OpenTracing.Contrib.NetCore/Logging/OpenTracingLoggerProvider.cs

@@ -10,24 +10,17 @@ namespace OpenTracing.Contrib.NetCore.Logging
     [ProviderAlias("OpenTracing")]
     internal class OpenTracingLoggerProvider : ILoggerProvider
     {
-        private readonly ITracer _tracer;
+        private readonly IGlobalTracerAccessor _globalTracerAccessor;
 
         public OpenTracingLoggerProvider(IGlobalTracerAccessor globalTracerAccessor)
         {
-            // HACK: We can't use ITracer directly here because this would lead to a StackOverflowException
-            // (due to a circular dependency) if the ITracer needs a ILoggerFactory.
-            // https://github.com/opentracing-contrib/csharp-netcore/issues/14
-
-            if (globalTracerAccessor == null)
-                throw new ArgumentNullException(nameof(globalTracerAccessor));
-
-            _tracer = globalTracerAccessor.GetGlobalTracer();
+            _globalTracerAccessor = globalTracerAccessor ?? throw new ArgumentNullException(nameof(globalTracerAccessor));
         }
 
         /// <inheritdoc/>
         public ILogger CreateLogger(string categoryName)
         {
-            return new OpenTracingLogger(_tracer, categoryName);
+            return new OpenTracingLogger(_globalTracerAccessor, categoryName);
         }
 
         public void Dispose()