[HttpClient] update network.protocol.version values as per specification

src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md

@@ -41,6 +41,9 @@
   ([#5005](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5005))
   ([#5034](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5034))
 
+* Fixed `network.protocol.version` attribute values to match the specification.
+  ([#5006](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5006))
+
 ## 1.6.0-beta.2
 
 Released 2023-Oct-26

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs

@@ -205,7 +205,7 @@ public void OnStartActivity(Activity activity, object payload)
                 }
 
                 activity.SetTag(SemanticConventions.AttributeUrlFull, HttpTagHelper.GetUriTagValueFromRequestUri(request.RequestUri));
-                activity.SetTag(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetFlavorTagValueFromProtocolVersion(request.Version));
+                activity.SetTag(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetProtocolVersionString(request.Version));
 
                 if (request.Headers.TryGetValues("User-Agent", out var userAgentValues))
                 {

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs

@@ -130,7 +130,7 @@ public void OnStopEventWritten(Activity activity, object payload)
 
                 tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeServerAddress, request.RequestUri.Host));
                 tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeUrlScheme, request.RequestUri.Scheme));
-                tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetFlavorTagValueFromProtocolVersion(request.Version)));
+                tags.Add(new KeyValuePair<string, object>(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetProtocolVersionString(request.Version)));
 
                 if (!request.RequestUri.IsDefaultPort)
                 {

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpTagHelper.cs

@@ -78,6 +78,15 @@ public static string GetUriTagValueFromRequestUri(Uri uri)
         return string.Concat(uri.Scheme, Uri.SchemeDelimiter, uri.Authority, uri.PathAndQuery, uri.Fragment);
     }
 
+    public static string GetProtocolVersionString(Version httpVersion) => (httpVersion.Major, httpVersion.Minor) switch
+    {
+        (1, 0) => "1.0",
+        (1, 1) => "1.1",
+        (2, 0) => "2",
+        (3, 0) => "3",
+        _ => httpVersion.ToString(),
+    };
+
     private static string ConvertMethodToOperationName(string method) => $"HTTP {method}";
 
     private static string ConvertHttpMethodToOperationName(HttpMethod method) => $"HTTP {method}";

src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs

@@ -173,7 +173,7 @@ private static void AddRequestTagsAndInstrumentRequest(HttpWebRequest request, A
                 }
 
                 activity.SetTag(SemanticConventions.AttributeUrlFull, HttpTagHelper.GetUriTagValueFromRequestUri(request.RequestUri));
-                activity.SetTag(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetFlavorTagValueFromProtocolVersion(request.ProtocolVersion));
+                activity.SetTag(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetProtocolVersionString(request.ProtocolVersion));
             }
 
             try
@@ -531,7 +531,7 @@ private static void ProcessResult(IAsyncResult asyncResult, AsyncCallback asyncC
 
                 tags.Add(SemanticConventions.AttributeServerAddress, request.RequestUri.Host);
                 tags.Add(SemanticConventions.AttributeUrlScheme, request.RequestUri.Scheme);
-                tags.Add(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetFlavorTagValueFromProtocolVersion(request.ProtocolVersion));
+                tags.Add(SemanticConventions.AttributeNetworkProtocolVersion, HttpTagHelper.GetProtocolVersionString(request.ProtocolVersion));
                 if (!request.RequestUri.IsDefaultPort)
                 {
                     tags.Add(SemanticConventions.AttributeServerPort, request.RequestUri.Port);