Implement centralized HttpClient service with proxy support (#857)

* Initial plan

* Implement HttpClient service infrastructure and update existing services

Co-authored-by: jongio <[email protected]>

* Add comprehensive unit tests for HttpClient service

Co-authored-by: jongio <[email protected]>

* Add comprehensive documentation for HttpClient service design

Co-authored-by: jongio <[email protected]>

* Run dotnet format to fix code formatting issues

Co-authored-by: jongio <[email protected]>

* Update CHANGELOG.md with link to PR 857 for HttpClient service implementation

Co-authored-by: jongio <[email protected]>

* Fix compilation errors in HttpClient service implementation

Co-authored-by: jongio <[email protected]>

* Fix regex parsing error in proxy bypass patterns

Co-authored-by: jongio <[email protected]>

* Fix whitespace formatting in KustoCommandTests.cs

Co-authored-by: jongio <[email protected]>

* Update .gitignore

* Enhance FoundryService constructor to accept optional ITenantService and update HttpClientService proxy logic to prioritize HTTPS_PROXY

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: jongio <[email protected]>

Author: Copilot

CHANGELOG.md

@@ -53,6 +53,7 @@ The Azure MCP Server updates automatically by default whenever a new release com
 
 ### Other Changes
 
+- Implemented centralized HttpClient service with proxy support for better resource management and enterprise compatibility. [[#857](https://github.com/Azure/azure-mcp/pull/857)]
 - Added caching for Cosmos DB databases and containers. [[813](https://github.com/Azure/azure-mcp/pull/813)]
 - Refactored PostgreSQL commands to follow ObjectVerb naming pattern, fix command hierarchy, and ensure all commands end with verbs. This improves consistency and discoverability across all postgres commands. [[#865](https://github.com/Azure/azure-mcp/issues/865)] [[#866](https://github.com/Azure/azure-mcp/pull/866)]
 

areas/foundry/src/AzureMcp.Foundry/Services/FoundryService.cs

@@ -10,13 +10,16 @@
 using Azure.ResourceManager.Resources;
 using AzureMcp.Core.Options;
 using AzureMcp.Core.Services.Azure;
+using AzureMcp.Core.Services.Azure.Tenant;
+using AzureMcp.Core.Services.Http;
 using AzureMcp.Foundry.Commands;
 using AzureMcp.Foundry.Models;
 
 namespace AzureMcp.Foundry.Services;
 
-public class FoundryService : BaseAzureService, IFoundryService
+public class FoundryService(IHttpClientService httpClientService, ITenantService? tenantService = null) : BaseAzureService(tenantService), IFoundryService
 {
+    private readonly IHttpClientService _httpClientService = httpClientService ?? throw new ArgumentNullException(nameof(httpClientService));
     public async Task<List<ModelInformation>> ListModels(
         bool searchForFreePlayground = false,
         string publisherName = "",
@@ -63,7 +66,7 @@ public async Task<List<ModelInformation>> ListModels(
                         Encoding.UTF8,
                         "application/json");
 
-                    var httpResponse = await new HttpClient().PostAsync(url, content);
+                    var httpResponse = await _httpClientService.DefaultClient.PostAsync(url, content);
                     httpResponse.EnsureSuccessStatusCode();
 
                     var responseText = await httpResponse.Content.ReadAsStringAsync();

areas/kusto/src/AzureMcp.Kusto/Services/KustoClient.cs

@@ -3,18 +3,20 @@
 
 using System.Text.Json.Nodes;
 using Azure.Core;
+using AzureMcp.Core.Services.Http;
 
 namespace AzureMcp.Kusto.Services;
 
 public class KustoClient(
     string clusterUri,
     TokenCredential tokenCredential,
-    string userAgent)
+    string userAgent,
+    IHttpClientService httpClientService)
 {
     private readonly string _clusterUri = clusterUri;
     private readonly TokenCredential _tokenCredential = tokenCredential;
     private readonly string _userAgent = userAgent;
-    private readonly HttpClient _httpClient = new() { BaseAddress = new Uri(clusterUri) };
+    private readonly HttpClient _httpClient = httpClientService.CreateClient(new Uri(clusterUri));
     private static readonly string s_application = "AzureMCP";
     private static readonly string s_clientRequestIdPrefix = "AzMcp";
     private static readonly string s_default_scope = "https://kusto.kusto.windows.net/.default";

areas/kusto/src/AzureMcp.Kusto/Services/KustoService.cs

@@ -7,6 +7,7 @@
 using AzureMcp.Core.Services.Azure.Subscription;
 using AzureMcp.Core.Services.Azure.Tenant;
 using AzureMcp.Core.Services.Caching;
+using AzureMcp.Core.Services.Http;
 using AzureMcp.Kusto.Commands;
 
 namespace AzureMcp.Kusto.Services;
@@ -15,10 +16,12 @@ namespace AzureMcp.Kusto.Services;
 public sealed class KustoService(
     ISubscriptionService subscriptionService,
     ITenantService tenantService,
-    ICacheService cacheService) : BaseAzureService(tenantService), IKustoService
+    ICacheService cacheService,
+    IHttpClientService httpClientService) : BaseAzureService(tenantService), IKustoService
 {
     private readonly ISubscriptionService _subscriptionService = subscriptionService ?? throw new ArgumentNullException(nameof(subscriptionService));
     private readonly ICacheService _cacheService = cacheService ?? throw new ArgumentNullException(nameof(cacheService));
+    private readonly IHttpClientService _httpClientService = httpClientService ?? throw new ArgumentNullException(nameof(httpClientService));
 
     private const string CacheGroup = "kusto";
     private const string KustoClustersCacheKey = "clusters";
@@ -285,7 +288,7 @@ private async Task<KustoClient> GetOrCreateKustoClient(string clusterUri, string
         if (kustoClient == null)
         {
             var tokenCredential = await GetCredential(tenant);
-            kustoClient = new KustoClient(clusterUri, tokenCredential, UserAgent);
+            kustoClient = new KustoClient(clusterUri, tokenCredential, UserAgent, _httpClientService);
             await _cacheService.SetAsync(CacheGroup, providerCacheKey, kustoClient, s_providerCacheDuration);
         }
 
@@ -299,7 +302,7 @@ private async Task<KustoClient> GetOrCreateCslQueryProvider(string clusterUri, s
         if (kustoClient == null)
         {
             var tokenCredential = await GetCredential(tenant);
-            kustoClient = new KustoClient(clusterUri, tokenCredential, UserAgent);
+            kustoClient = new KustoClient(clusterUri, tokenCredential, UserAgent, _httpClientService);
             await _cacheService.SetAsync(CacheGroup, providerCacheKey, kustoClient, s_providerCacheDuration);
         }
 

areas/kusto/tests/AzureMcp.Kusto.LiveTests/KustoCommandTests.cs

@@ -3,12 +3,15 @@
 
 using System.Text.Json;
 using Azure.Identity;
+using AzureMcp.Core.Services.Http;
 using AzureMcp.Kusto.Services;
 using AzureMcp.Tests;
 using AzureMcp.Tests.Client;
 using AzureMcp.Tests.Client.Helpers;
+using Microsoft.Extensions.Options;
 using ModelContextProtocol.Client;
 using Xunit;
+using MsOptions = Microsoft.Extensions.Options.Options;
 
 namespace AzureMcp.Kusto.LiveTests;
 
@@ -38,7 +41,12 @@ public async ValueTask InitializeAsync()
                 { "cluster", Settings.ResourceBaseName }
                 });
             var clusterUri = clusterInfo.AssertProperty("cluster").AssertProperty("clusterUri").GetString();
-            var kustoClient = new KustoClient(clusterUri ?? string.Empty, credentials, "ua");
+
+            // Create HttpClientService for KustoClient
+            var httpClientOptions = new HttpClientOptions();
+            var httpClientService = new HttpClientService(MsOptions.Create(httpClientOptions));
+
+            var kustoClient = new KustoClient(clusterUri ?? string.Empty, credentials, "ua", httpClientService);
             var resp = await kustoClient.ExecuteControlCommandAsync(
                 TestDatabaseName,
                 ".set-or-replace ToDoList <| datatable (Title: string, IsCompleted: bool) [' Hello World!', false]",

areas/monitor/src/AzureMcp.Monitor/Services/MonitorHealthModelService.cs

@@ -6,17 +6,18 @@
 using AzureMcp.Core.Options;
 using AzureMcp.Core.Services.Azure;
 using AzureMcp.Core.Services.Azure.Tenant;
+using AzureMcp.Core.Services.Http;
 
 namespace AzureMcp.Monitor.Services;
 
-public class MonitorHealthModelService(ITenantService tenantService)
+public class MonitorHealthModelService(ITenantService tenantService, IHttpClientService httpClientService)
     : BaseAzureService(tenantService), IMonitorHealthModelService
 {
     private const int TokenExpirationBuffer = 300;
     private const string ManagementApiBaseUrl = "https://management.azure.com";
     private const string HealthModelsDataApiScope = "https://data.healthmodels.azure.com";
     private const string ApiVersion = "2023-10-01-preview";
-    private static readonly HttpClient s_sharedHttpClient = new HttpClient();
+    private readonly IHttpClientService _httpClientService = httpClientService;
 
     private string? _cachedDataplaneAccessToken;
     private string? _cachedControlPlaneAccessToken;
@@ -60,7 +61,7 @@ private async Task<string> GetDataplaneResponseAsync(string url)
         using var request = new HttpRequestMessage(HttpMethod.Get, url);
         request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", dataplaneToken);
 
-        HttpResponseMessage healthResponse = await s_sharedHttpClient.SendAsync(request);
+        HttpResponseMessage healthResponse = await _httpClientService.DefaultClient.SendAsync(request);
         healthResponse.EnsureSuccessStatusCode();
 
         string healthResponseString = await healthResponse.Content.ReadAsStringAsync();
@@ -75,7 +76,7 @@ private async Task<string> GetDataplaneEndpointAsync(string subscriptionId, stri
         using var request = new HttpRequestMessage(HttpMethod.Get, healthModelUrl);
         request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
 
-        HttpResponseMessage response = await s_sharedHttpClient.SendAsync(request);
+        HttpResponseMessage response = await _httpClientService.DefaultClient.SendAsync(request);
         response.EnsureSuccessStatusCode();
         string responseString = await response.Content.ReadAsStringAsync();
 

core/src/AzureMcp.Core/Areas/Server/Commands/ServiceCollectionExtensions.cs

@@ -7,6 +7,7 @@
 using AzureMcp.Core.Areas.Server.Commands.ToolLoading;
 using AzureMcp.Core.Areas.Server.Options;
 using AzureMcp.Core.Commands;
+using AzureMcp.Core.Extensions;
 using AzureMcp.Core.Services.Telemetry;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -34,6 +35,9 @@ public static class AzureMcpServiceCollectionExtensions
     /// <returns>The service collection with MCP server services added.</returns>
     public static IServiceCollection AddAzureMcpServer(this IServiceCollection services, ServiceStartOptions serviceStartOptions)
     {
+        // Register HTTP client services
+        services.AddHttpClientServices();
+
         // Register options for service start
         services.AddSingleton(serviceStartOptions);
         services.AddSingleton(Options.Create(serviceStartOptions));

core/src/AzureMcp.Core/Extensions/HttpClientServiceCollectionExtensions.cs

@@ -0,0 +1,54 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using AzureMcp.Core.Services.Http;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace AzureMcp.Core.Extensions;
+
+/// <summary>
+/// Extension methods for registering HTTP client services.
+/// </summary>
+public static class HttpClientServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds HTTP client services to the service collection with default configuration.
+    /// </summary>
+    /// <param name="services">The service collection.</param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddHttpClientServices(this IServiceCollection services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        return services.AddHttpClientServices(_ => { });
+    }
+
+    /// <summary>
+    /// Adds HTTP client services to the service collection with custom configuration.
+    /// </summary>
+    /// <param name="services">The service collection.</param>
+    /// <param name="configureOptions">Action to configure HttpClient options.</param>
+    /// <returns>The service collection for chaining.</returns>
+    public static IServiceCollection AddHttpClientServices(this IServiceCollection services, Action<HttpClientOptions> configureOptions)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(configureOptions);
+
+        // Configure options with environment variables
+        services.Configure<HttpClientOptions>(options =>
+        {
+            // Read proxy configuration from environment variables
+            options.AllProxy = Environment.GetEnvironmentVariable("ALL_PROXY");
+            options.HttpProxy = Environment.GetEnvironmentVariable("HTTP_PROXY");
+            options.HttpsProxy = Environment.GetEnvironmentVariable("HTTPS_PROXY");
+            options.NoProxy = Environment.GetEnvironmentVariable("NO_PROXY");
+
+            // Apply custom configuration
+            configureOptions(options);
+        });
+
+        // Register the HTTP client service
+        services.AddSingleton<IHttpClientService, HttpClientService>();
+
+        return services;
+    }
+}

core/src/AzureMcp.Core/Services/Http/HttpClientOptions.cs

@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace AzureMcp.Core.Services.Http;
+
+/// <summary>
+/// Configuration options for HttpClient services.
+/// </summary>
+public sealed class HttpClientOptions
+{
+    /// <summary>
+    /// Gets or sets the HTTP proxy address. Can be set via HTTP_PROXY environment variable.
+    /// </summary>
+    public string? HttpProxy { get; set; }
+
+    /// <summary>
+    /// Gets or sets the HTTPS proxy address. Can be set via HTTPS_PROXY environment variable.
+    /// </summary>
+    public string? HttpsProxy { get; set; }
+
+    /// <summary>
+    /// Gets or sets the proxy address for all protocols. Can be set via ALL_PROXY environment variable.
+    /// </summary>
+    public string? AllProxy { get; set; }
+
+    /// <summary>
+    /// Gets or sets the comma-separated list of hostnames that should bypass the proxy. Can be set via NO_PROXY environment variable.
+    /// </summary>
+    public string? NoProxy { get; set; }
+
+    /// <summary>
+    /// Gets or sets the default timeout for HTTP requests. Defaults to 100 seconds.
+    /// </summary>
+    public TimeSpan DefaultTimeout { get; set; } = TimeSpan.FromSeconds(100);
+
+    /// <summary>
+    /// Gets or sets the default User-Agent header value.
+    /// </summary>
+    public string? DefaultUserAgent { get; set; }
+}