Add Azure collector

src/OpenTelemetry.Collector.Dependencies/AzureSdkCollector.cs

@@ -0,0 +1,134 @@
+// <copyright file="AzureSdkCollector.cs" company="OpenTelemetry Authors">
+// Copyright 2018, OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+namespace OpenTelemetry.Collector.Dependencies
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Diagnostics;
+    using OpenTelemetry.Context;
+    using OpenTelemetry.Trace;
+
+    public class AzureSdkCollector : IDisposable, IObserver<DiagnosticListener>, IObserver<KeyValuePair<string, object>>
+    {
+        private readonly ITracer tracer;
+
+        private readonly ISampler sampler;
+
+        private List<IDisposable> subscriptions = new List<IDisposable>();
+
+        public AzureSdkCollector(ITracer tracer, ISampler sampler)
+        {
+            this.tracer = tracer;
+            this.sampler = sampler;
+
+            this.subscriptions.Add(DiagnosticListener.AllListeners.Subscribe(this));
+        }
+
+        public void Dispose()
+        {
+            lock (this.subscriptions)
+            {
+                foreach (var subscription in this.subscriptions)
+                {
+                    subscription.Dispose();
+                }
+            }
+        }
+
+        public void OnCompleted()
+        {
+        }
+
+        public void OnError(Exception error)
+        {
+        }
+
+        public void OnNext(KeyValuePair<string, object> value)
+        {
+            try
+            {
+                if (value.Key.EndsWith("Start"))
+                {
+                    this.OnStartActivity(Activity.Current, value.Value);
+                }
+                else if (value.Key.EndsWith("Stop"))
+                {
+                    // Current.Parent is used because OT wraps additional Activity over
+                    this.OnStopActivity(Activity.Current, value.Value);
+                }
+                else if (value.Key.EndsWith("Exception"))
+                {
+                    // Current.Parent is used because OT wraps additional Activity over
+                    this.OnException(Activity.Current, value.Value);
+                }
+            }
+            catch (Exception)
+            {
+                // TODO: Log
+            }
+        }
+
+        public void OnNext(DiagnosticListener value)
+        {
+            if (value.Name.StartsWith("Azure"))
+            {
+                lock (this.subscriptions)
+                {
+                    this.subscriptions.Add(value.Subscribe(this));
+                }
+            }
+        }
+
+        private void OnStartActivity(Activity current, object valueValue)
+        {
+            var operationName = current.OperationName;
+            foreach (var keyValuePair in current.Tags)
+            {
+                if (keyValuePair.Key == "http.url")
+                {
+                    operationName = keyValuePair.Value;
+                }
+            }
+
+            var span = this.tracer.SpanBuilder(operationName)
+                .SetCreateChild(false)
+                .SetSpanKind(SpanKind.Client)
+                .SetSampler(this.sampler)
+                .StartSpan();
+
+            this.tracer.WithSpan(span);
+        }
+
+        private void OnStopActivity(Activity current, object valueValue)
+        {
+            var span = this.tracer.CurrentSpan;
+            foreach (var keyValuePair in current.Tags)
+            {
+                span.SetAttribute(keyValuePair.Key, keyValuePair.Value);
+            }
+
+            this.tracer.CurrentSpan.End();
+        }
+
+        private void OnException(Activity current, object valueValue)
+        {
+            var span = this.tracer.CurrentSpan;
+
+            span.Status = Status.Unknown.WithDescription(valueValue?.ToString());
+        }
+    }
+}

src/OpenTelemetry.Exporter.Zipkin/Implementation/TraceExporterHandler.cs

@@ -91,7 +91,7 @@ internal ZipkinSpan GenerateSpan(SpanData spanData, ZipkinEndpoint localEndpoint
 
             foreach (var label in spanData.Attributes.AttributeMap)
             {
-                spanBuilder.PutTag(label.Key, (string)label.Value);
+                spanBuilder.PutTag(label.Key, label.Value.ToString());
             }
 
             var status = spanData.Status;