Add additional tags to ASP.NET Core metrics

src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+* Added additional metric dimensions.
+  ([3247](https://github.com/open-telemetry/opentelemetry-dotnet/pull/3247))
+
 * Removes net5.0 target as .NET 5.0 is going out
   of support. The package keeps netstandard2.1 target, so it
   can still be used with .NET5.0 apps.

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs

@@ -17,6 +17,9 @@
 using System.Diagnostics;
 using System.Diagnostics.Metrics;
 using Microsoft.AspNetCore.Http;
+#if NETCOREAPP
+using Microsoft.AspNetCore.Routing;
+#endif
 using OpenTelemetry.Trace;
 
 namespace OpenTelemetry.Instrumentation.AspNetCore.Implementation
@@ -51,16 +54,60 @@ public override void OnStopActivity(Activity activity, object payload)
                 return;
             }
 
+            string host;
+
+            if (context.Request.Host.Port is null or 80 or 443)
+            {
+                host = context.Request.Host.Host;
+            }
+            else
+            {
+                host = context.Request.Host.Host + ":" + context.Request.Host.Port;
+            }
+
+            TagList tags;
+
+            // We need following directive as
+            // RouteEndpoint is not available in netstandard2.0 and netstandard2.1
+#if NETCOREAPP
+            var target = (context.GetEndpoint() as RouteEndpoint)?.RoutePattern.RawText;
+
             // TODO: This is just a minimal set of attributes. See the spec for additional attributes:
             // https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/http-metrics.md#http-server
-            var tags = new TagList
+            if (!string.IsNullOrEmpty(target))
+            {
+                tags = new TagList
+                {
+                    { SemanticConventions.AttributeHttpFlavor, context.Request.Protocol },
+                    { SemanticConventions.AttributeHttpScheme, context.Request.Scheme },
+                    { SemanticConventions.AttributeHttpMethod, context.Request.Method },
+                    { SemanticConventions.AttributeHttpHost, host },
+                    { SemanticConventions.AttributeHttpTarget, target },
+                    { SemanticConventions.AttributeHttpStatusCode, context.Response.StatusCode.ToString() },
+                };
+            }
+            else
+            {
+                tags = new TagList
+                {
+                    { SemanticConventions.AttributeHttpFlavor, context.Request.Protocol },
+                    { SemanticConventions.AttributeHttpScheme, context.Request.Scheme },
+                    { SemanticConventions.AttributeHttpMethod, context.Request.Method },
+                    { SemanticConventions.AttributeHttpHost, host },
+                    { SemanticConventions.AttributeHttpStatusCode, context.Response.StatusCode.ToString() },
+                };
+            }
+#else
+            tags = new TagList
             {
-                { SemanticConventions.AttributeHttpMethod, context.Request.Method },
-                { SemanticConventions.AttributeHttpScheme, context.Request.Scheme },
-                { SemanticConventions.AttributeHttpStatusCode, context.Response.StatusCode },
                 { SemanticConventions.AttributeHttpFlavor, context.Request.Protocol },
+                { SemanticConventions.AttributeHttpScheme, context.Request.Scheme },
+                { SemanticConventions.AttributeHttpMethod, context.Request.Method },
+                { SemanticConventions.AttributeHttpHost, host },
+                { SemanticConventions.AttributeHttpStatusCode, context.Response.StatusCode.ToString() },
             };
 
+#endif
             this.httpServerDuration.Record(activity.Duration.TotalMilliseconds, tags);
         }
     }

test/OpenTelemetry.Instrumentation.AspNetCore.Tests/MetricTests.cs

@@ -116,13 +116,17 @@ public async Task RequestMetricIsCaptured()
 
             var method = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpMethod, "GET");
             var scheme = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpScheme, "http");
-            var statusCode = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpStatusCode, 200);
+            var statusCode = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpStatusCode, "200");
             var flavor = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpFlavor, "HTTP/1.1");
+            var host = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpHost, "localhost");
+            var target = new KeyValuePair<string, object>(SemanticConventions.AttributeHttpTarget, "api/Values");
             Assert.Contains(method, attributes);
             Assert.Contains(scheme, attributes);
             Assert.Contains(statusCode, attributes);
             Assert.Contains(flavor, attributes);
-            Assert.Equal(4, attributes.Length);
+            Assert.Contains(host, attributes);
+            Assert.Contains(target, attributes);
+            Assert.Equal(6, attributes.Length);
         }
 
         public void Dispose()