Add request tracing for push refresh usage (#626)

* in progress

* complete adding ispushrefreshused logic

* rename pushrefresh tag string

* remove empty line

Author: amerjusupovic

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/AzureAppConfigurationProvider.cs

@@ -548,6 +548,11 @@ public void ProcessPushNotification(PushNotification pushNotification, TimeSpan?
 
             if (_configClientManager.UpdateSyncToken(pushNotification.ResourceUri, pushNotification.SyncToken))
             {
+                if (_requestTracingEnabled && _requestTracingOptions != null)
+                {
+                    _requestTracingOptions.IsPushRefreshUsed = true;
+                }
+
                 SetDirty(maxDelay);
             }
             else

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/Constants/RequestTracingConstants.cs

@@ -33,6 +33,7 @@ internal class RequestTracingConstants
         public const string LoadBalancingEnabledTag = "LB";
         public const string SignalRUsedTag = "SignalR";
         public const string FailoverRequestTag = "Failover";
+        public const string PushRefreshTag = "PushRefresh";
 
         public const string FeatureFlagFilterTypeKey = "Filter";
         public const string CustomFilter = "CSTM";

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/RequestTracingOptions.cs

@@ -63,6 +63,11 @@ internal class RequestTracingOptions
         /// </summary>
         public bool IsFailoverRequest { get; set; } = false;
 
+        /// <summary>
+        /// Flag to indicate whether push refresh is used.
+        /// </summary>
+        public bool IsPushRefreshUsed { get; set; } = false;
+
         /// <summary>
         /// Checks whether any tracing feature is used.
         /// </summary>

src/Microsoft.Extensions.Configuration.AzureAppConfiguration/TracingUtils.cs

@@ -201,6 +201,11 @@ private static string CreateCorrelationContextHeader(RequestType requestType, Re
                 correlationContextTags.Add(RequestTracingConstants.FailoverRequestTag);
             }
 
+            if (requestTracingOptions.IsPushRefreshUsed)
+            {
+                correlationContextTags.Add(RequestTracingConstants.PushRefreshTag);
+            }
+
             var sb = new StringBuilder();
 
             foreach (KeyValuePair<string, string> kvp in correlationContextKeyValues)