Support W3C distributed tracing standard

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## Version 2.8.0-beta1
+- [Adds opt-in support for W3C distributed tracing standard](https://github.com/Microsoft/ApplicationInsights-dotnet-server/pull/945)
+
 ## Version 2.7.2
 - [Fix ServiceBus requests correlation](https://github.com/Microsoft/ApplicationInsights-dotnet-server/issues/970)
 

Src/Common/Common.projitems

@@ -19,6 +19,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)RequestResponseHeaders.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SdkVersionUtils.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)StringUtilities.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)W3C\W3CActivityExtensions.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)W3C\W3CConstants.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)W3C\W3COperationCorrelationTelemetryInitializer.cs" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' != 'netstandard1.6' ">
     <Compile Include="$(MSBuildThisFileDirectory)WebHeaderCollectionExtensions.cs" />

Src/Common/InjectionGuardConstants.cs

@@ -5,16 +5,46 @@
     /// These max limits are intentionally exaggerated to allow for unexpected responses, while still guarding against unreasonably large responses.
     /// Example: While a 32 character response may be expected, 50 characters may be permitted while a 10,000 character response would be unreasonable and malicious.
     /// </summary>
-    public static class InjectionGuardConstants
+#if DEPENDENCY_COLLECTOR
+    public
+#else
+    internal
+#endif
+    static class InjectionGuardConstants
     {
         /// <summary>
         /// Max length of AppId allowed in response from Breeze.
         /// </summary>
-        public const int AppIdMaxLengeth = 50;
+        public const int AppIdMaxLength = 50;
 
         /// <summary>
         /// Max length of incoming Request Header value allowed.
         /// </summary>
         public const int RequestHeaderMaxLength = 1024;
+
+        /// <summary>
+        /// Max length of context header key.
+        /// </summary>
+        public const int ContextHeaderKeyMaxLength = 50;
+
+        /// <summary>
+        /// Max length of context header value.
+        /// </summary>
+        public const int ContextHeaderValueMaxLength = 1024;
+
+        /// <summary>
+        /// Max length of traceparent header value.
+        /// </summary>
+        public const int TraceParentHeaderMaxLength = 55;
+
+        /// <summary>
+        /// Max length of tracestate header value string.
+        /// </summary>
+        public const int TraceStateHeaderMaxLength = 512;
+
+        /// <summary>
+        /// Max number of key value pairs in the tracestate header.
+        /// </summary>
+        public const int TraceStateMaxPairs = 32;
     }
 }

Src/Common/StringUtilities.cs

@@ -7,7 +7,12 @@
     /// <summary>
     /// Generic functions to perform common operations on a string.
     /// </summary>
-    public static class StringUtilities
+#if DEPENDENCY_COLLECTOR
+    public
+#else
+    internal
+#endif
+    static class StringUtilities
     {
         private static readonly uint[] Lookup32 = CreateLookup32();
 
@@ -35,11 +40,57 @@ public static string EnforceMaxLength(string input, int maxLength)
         /// <returns>Random 16 bytes array encoded as hex string</returns>
         public static string GenerateTraceId()
         {
-            // See https://stackoverflow.com/questions/311165/how-do-you-convert-a-byte-array-to-a-hexadecimal-string-and-vice-versa/24343727#24343727
-            var bytes = Guid.NewGuid().ToByteArray();
+            return GenerateId(Guid.NewGuid().ToByteArray(), 0, 16);
+        }
+
+        /// <summary>
+        /// Generates random span Id as per W3C Distributed tracing specification.
+        /// https://github.com/w3c/distributed-tracing/blob/master/trace_context/HTTP_HEADER_FORMAT.md#span-id
+        /// </summary>
+        /// <returns>Random 8 bytes array encoded as hex string</returns>
+        public static string GenerateSpanId()
+        {
+            return GenerateId(Guid.NewGuid().ToByteArray(), 0, 8);
+        }
+
+        /// <summary>
+        /// Formats trace Id and span Id into valid Request-Id: |trace.span.
+        /// </summary>
+        /// <param name="traceId">Trace Id.</param>
+        /// <param name="spanId">Span id.</param>
+        /// <returns>valid Request-Id.</returns>
+        public static string FormatRequestId(string traceId, string spanId)
+        {
+            return String.Concat("|", traceId, ".", spanId, ".");
+        }
 
-            var result = new char[32];
-            for (int i = 0; i < 16; i++)
+        /// <summary>
+        /// Gets root id (string between '|' and the first dot) from the hierarchical Id.
+        /// </summary>
+        /// <param name="hierarchicalId">Id to extract root from.</param>
+        /// <returns>Root operation id.</returns>
+        internal static string GetRootId(string hierarchicalId)
+        {
+            // Returns the root Id from the '|' to the first '.' if any.
+            int rootEnd = hierarchicalId.IndexOf('.');
+            if (rootEnd < 0)
+            {
+                rootEnd = hierarchicalId.Length;
+            }
+
+            int rootStart = hierarchicalId[0] == '|' ? 1 : 0;
+            return hierarchicalId.Substring(rootStart, rootEnd - rootStart);
+        }
+
+        /// <summary>
+        /// Converts byte array to hex lower case string.
+        /// </summary>
+        /// <returns>Array encoded as hex string</returns>
+        private static string GenerateId(byte[] bytes, int start, int length)
+        {
+            // See https://stackoverflow.com/questions/311165/how-do-you-convert-a-byte-array-to-a-hexadecimal-string-and-vice-versa/24343727#24343727
+            var result = new char[length * 2];
+            for (int i = start; i < start + length; i++)
             {
                 var val = Lookup32[bytes[i]];
                 result[2 * i] = (char)val;

Src/Common/W3C/W3CActivityExtensions.cs

@@ -0,0 +1,255 @@
+namespace Microsoft.ApplicationInsights.W3C
+{
+    using System;
+    using System.ComponentModel;
+    using System.Diagnostics;
+    using System.Globalization;
+    using System.Linq;
+    using Microsoft.ApplicationInsights.Common;
+
+    /// <summary>
+    /// Extends Activity to support W3C distributed tracing standard.
+    /// </summary>
+    [Obsolete("Not ready for public consumption.")]
+    [EditorBrowsable(EditorBrowsableState.Never)]
+#if DEPENDENCY_COLLECTOR
+    public
+#else
+    internal
+#endif
+    static class W3CActivityExtensions
+    {
+        /// <summary>
+        /// Generate new W3C context.
+        /// </summary>
+        /// <param name="activity">Activity to generate W3C context on.</param>
+        /// <returns>The same Activity for chaining.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static Activity GenerateW3CContext(this Activity activity)
+        {
+            activity.SetVersion(W3CConstants.DefaultVersion);
+            activity.SetSampled(W3CConstants.TraceFlagRecordedAndNotRequested);
+            activity.SetSpanId(StringUtilities.GenerateSpanId());
+            activity.SetTraceId(StringUtilities.GenerateTraceId());
+            return activity;
+        }
+
+        /// <summary>
+        /// Checks if current Actuvuty has W3C properties on it.
+        /// </summary>
+        /// <param name="activity">Activity to check.</param>
+        /// <returns>True if Activity has W3C properties, false otherwise.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static bool IsW3CActivity(this Activity activity)
+        {
+            return activity != null && activity.Tags.Any(t => t.Key == W3CConstants.TraceIdTag);
+        }
+
+        /// <summary>
+        /// Updates context on the Activity based on the W3C Context in the parent Activity tree.
+        /// </summary>
+        /// <param name="activity">Activity to update W3C context on.</param>
+        /// <returns>The same Activity for chaining.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static Activity UpdateContextOnActivity(this Activity activity)
+        {
+            if (activity == null || activity.Tags.Any(t => t.Key == W3CConstants.TraceIdTag))
+            {
+                return activity;
+            }
+
+            // no w3c Tags on Activity
+            activity.Parent.UpdateContextOnActivity();
+
+            // at this point, Parent has W3C tags, but current activity does not - update it
+            return activity.UpdateContextFromParent();
+        }
+
+        /// <summary>
+        /// Gets traceparent header value for the Activity or null if there is no W3C context on it.
+        /// </summary>
+        /// <param name="activity">Activity to read W3C context from.</param>
+        /// <returns>traceparent header value.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static string GetTraceparent(this Activity activity)
+        {
+            string version = null, traceId = null, spanId = null, sampled = null;
+            foreach (var tag in activity.Tags)
+            {
+                switch (tag.Key)
+                {
+                    case W3CConstants.TraceIdTag:
+                        traceId = tag.Value;
+                        break;
+                    case W3CConstants.SpanIdTag:
+                        spanId = tag.Value;
+                        break;
+                    case W3CConstants.VersionTag:
+                        version = tag.Value;
+                        break;
+                    case W3CConstants.SampledTag:
+                        sampled = tag.Value;
+                        break;
+                }
+            }
+
+            if (traceId == null || spanId == null || version == null || sampled == null)
+            {
+                return null;
+            }
+
+            return string.Join("-", version, traceId, spanId, sampled);
+        }
+
+        /// <summary>
+        /// Initializes W3C context on the Activity from traceparent header value.
+        /// </summary>
+        /// <param name="activity">Activity to set W3C context on.</param>
+        /// <param name="value">Valid traceparent header like 00-0af7651916cd43dd8448eb211c80319c-b9c7c989f97918e1-01.</param>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static void SetTraceparent(this Activity activity, string value)
+        {
+            if (value != null)
+            {
+                var parts = value.Trim(' ', '-').Split('-');
+                if (parts.Length == 4 && !activity.IsW3CActivity())
+                {
+                    string traceId = parts[1];
+                    string parentSpanId = parts[2];
+
+                    byte.TryParse(parts[3], NumberStyles.HexNumber, CultureInfo.InvariantCulture, out var sampled);
+
+                    if (traceId.Length == 32 && parentSpanId.Length == 16)
+                    {
+                        // we only support 00 version and ignore caller version
+                        activity.SetVersion(W3CConstants.DefaultVersion);
+
+                        // we always defer sampling
+                        if ((sampled & W3CConstants.RequestedTraceFlag) == W3CConstants.RequestedTraceFlag)
+                        {
+                            activity.SetSampled(W3CConstants.TraceFlagRecordedAndRequested);
+                        }
+                        else
+                        {
+                            activity.SetSampled(W3CConstants.TraceFlagRecordedAndNotRequested);
+                        }
+
+                        activity.SetParentSpanId(parentSpanId);
+                        activity.SetSpanId(StringUtilities.GenerateSpanId());
+                        activity.SetTraceId(traceId);
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Gets tracestate header value from the Activity.
+        /// </summary>
+        /// <param name="activity">Activity to get tracestate from.</param>
+        /// <returns>tracestate header value.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static string GetTracestate(this Activity activity) =>
+            activity.Tags.FirstOrDefault(t => t.Key == W3CConstants.TracestateTag).Value;
+
+        /// <summary>
+        /// Sets tracestate header value on the Activity.
+        /// </summary>
+        /// <param name="activity">Activity to set tracestate on.</param>
+        /// <param name="value">tracestate header value.</param>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static void SetTraceState(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.TracestateTag, value);
+
+        /// <summary>
+        /// Gets TraceId from the Activity.
+        /// Use carefully: if may cause iteration over all tags!
+        /// </summary>
+        /// <param name="activity">Activity to get traceId from.</param>
+        /// <returns>TraceId value or null if it does not exist.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static string GetTraceId(this Activity activity) => activity.Tags.FirstOrDefault(t => t.Key == W3CConstants.TraceIdTag).Value;
+
+        /// <summary>
+        /// Gets SpanId from the Activity.
+        /// Use carefully: if may cause iteration over all tags!
+        /// </summary>
+        /// <param name="activity">Activity to get spanId from.</param>
+        /// <returns>SpanId value or null if it does not exist.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static string GetSpanId(this Activity activity) => activity.Tags.FirstOrDefault(t => t.Key == W3CConstants.SpanIdTag).Value;
+
+        /// <summary>
+        /// Gets ParentSpanId from the Activity.
+        /// Use carefully: if may cause iteration over all tags!
+        /// </summary>
+        /// <param name="activity">Activity to get ParentSpanId from.</param>
+        /// <returns>ParentSpanId value or null if it does not exist.</returns>
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public static string GetParentSpanId(this Activity activity) => activity.Tags.FirstOrDefault(t => t.Key == W3CConstants.ParentSpanIdTag).Value;
+
+        [Obsolete("Not ready for public consumption.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        internal static void SetParentSpanId(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.ParentSpanIdTag, value);
+
+        private static void SetTraceId(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.TraceIdTag, value);
+
+        private static void SetSpanId(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.SpanIdTag, value);
+
+        private static void SetVersion(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.VersionTag, value);
+
+        private static void SetSampled(this Activity activity, string value) =>
+            activity.AddTag(W3CConstants.SampledTag, value);
+
+        private static Activity UpdateContextFromParent(this Activity activity)
+        {
+            if (activity != null && activity.Tags.All(t => t.Key != W3CConstants.TraceIdTag))
+            {
+                if (activity.Parent == null)
+                {
+                    activity.GenerateW3CContext();
+                }
+                else
+                {
+                    foreach (var tag in activity.Parent.Tags)
+                    {
+                        switch (tag.Key)
+                        {
+                            case W3CConstants.TraceIdTag:
+                                activity.SetTraceId(tag.Value);
+                                break;
+                            case W3CConstants.SpanIdTag:
+                                activity.SetParentSpanId(tag.Value);
+                                activity.SetSpanId(StringUtilities.GenerateSpanId());
+                                break;
+                            case W3CConstants.VersionTag:
+                                activity.SetVersion(tag.Value);
+                                break;
+                            case W3CConstants.SampledTag:
+                                activity.SetSampled(tag.Value);
+                                break;
+                            case W3CConstants.TracestateTag:
+                                activity.SetTraceState(tag.Value);
+                                break;
+                        }
+                    }
+                }
+            }
+
+            return activity;
+        }
+    }
+}