Add user-agent to all http clients using RawClientHttpRequestSettings.

src/Runner.Sdk/Util/VssUtil.cs

@@ -23,7 +23,13 @@ public static void InitializeVssClientSettings(List<ProductInfoHeaderValue> addi
 
             if (VssClientHttpRequestSettings.Default.UserAgent != null && VssClientHttpRequestSettings.Default.UserAgent.Count > 0)
             {
-                headerValues.AddRange(VssClientHttpRequestSettings.Default.UserAgent);
+                foreach (var headerVal in VssClientHttpRequestSettings.Default.UserAgent)
+                {
+                    if (!headerValues.Contains(headerVal))
+                    {
+                        headerValues.Add(headerVal);
+                    }
+                }
             }
 
             VssClientHttpRequestSettings.Default.UserAgent = headerValues;
@@ -33,6 +39,23 @@ public static void InitializeVssClientSettings(List<ProductInfoHeaderValue> addi
             {
                 VssClientHttpRequestSettings.Default.ServerCertificateValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
             }
+
+            var rawHeaderValues = new List<ProductInfoHeaderValue>();
+            rawHeaderValues.AddRange(additionalUserAgents);
+            rawHeaderValues.Add(new ProductInfoHeaderValue($"({StringUtil.SanitizeUserAgentHeader(RuntimeInformation.OSDescription)})"));
+
+            if (RawClientHttpRequestSettings.Default.UserAgent != null && RawClientHttpRequestSettings.Default.UserAgent.Count > 0)
+            {
+                foreach (var headerVal in RawClientHttpRequestSettings.Default.UserAgent)
+                {
+                    if (!rawHeaderValues.Contains(headerVal))
+                    {
+                        rawHeaderValues.Add(headerVal);
+                    }
+                }
+            }
+
+            RawClientHttpRequestSettings.Default.UserAgent = rawHeaderValues;
         }
 
         public static VssConnection CreateConnection(

src/Runner.Worker/JobRunner.cs

@@ -49,6 +49,9 @@ public async Task<TaskResult> RunAsync(AgentJobRequestMessage message, Cancellat
                 !string.IsNullOrEmpty(orchestrationId.Value))
             {
                 HostContext.UserAgents.Add(new ProductInfoHeaderValue("OrchestrationId", orchestrationId.Value));
+
+                // make sure orchestration id is in the user-agent header.
+                VssUtil.InitializeVssClientSettings(HostContext.UserAgents, HostContext.WebProxy);
             }
 
             var jobServerQueueTelemetry = false;

src/Sdk/Common/Common/RawHttpHeaders.cs

@@ -1,12 +1,11 @@
 using System;
 using System.ComponentModel;
-using System.Diagnostics.CodeAnalysis;
 
 namespace GitHub.Services.Common.Internal
 {
     [EditorBrowsable(EditorBrowsableState.Never)]
     public static class RawHttpHeaders
     {
-        public const String SessionHeader = "X-Runner-Session";
+        public const String SessionHeader = "X-Actions-Session";
     }
 }

src/Sdk/Common/Common/RawHttpMessageHandler.cs

@@ -138,6 +138,8 @@ protected override async Task<HttpResponseMessage> SendAsync(
                         response.Dispose();
                     }
 
+                    this.Settings.ApplyTo(request);
+
                     // Let's start with sending a token
                     IssuedToken token = null;
                     if (m_tokenProvider != null)