Enhances proxy configuration and removes custom logging (#225)

Improves HTTP proxy configuration to support authenticated proxies.
Parses username and password from the proxy URI to set credentials, while redacting them from the URI to prevent sensitive data logging.
Sets `BypassProxyOnLocal` to `true` by default, ensuring local requests bypass the proxy.
Removes the `ProxyLoggingHandler` as it is no longer necessary, simplifying the HTTP client pipeline.

Relates to CDMS-1245

Author: t11omas

BtmsGateway/Config/ConfigureServices.cs

@@ -35,8 +35,6 @@ public static void AddServices(this WebApplicationBuilder builder)
             Proxy.DefaultCdsHttpClientRetries
         );
 
-        builder.Services.AddTransient<ProxyLoggingHandler>();
-
         HttpRoutedClientWithRetryBuilder = builder.Services.AddHttpProxyRoutedClientWithRetry(httpClientTimeoutSeconds);
         HttpClientWithRetryBuilder = builder.Services.AddHttpProxyClientWithRetry(
             httpClientTimeoutSeconds,

BtmsGateway/Utils/Http/Proxy.cs

@@ -5,7 +5,7 @@
 using Polly.Extensions.Http;
 using Polly.Retry;
 using Polly.Timeout;
-using Serilog;
+using Environment = System.Environment;
 
 namespace BtmsGateway.Utils.Http;
 
@@ -25,7 +25,6 @@ public static IHttpClientBuilder AddHttpProxyClientWithoutRetry(this IServiceCol
         return services
             .AddHttpClient(ProxyClientWithoutRetry)
             .ConfigurePrimaryHttpMessageHandler(ConfigurePrimaryHttpMessageHandler)
-            .AddHttpMessageHandler<ProxyLoggingHandler>()
             .ConfigureHttpClient(client => client.Timeout = ConfigureHealthChecks.Timeout);
     }
 
@@ -48,7 +47,6 @@ int httpClientTimeoutInSeconds
         return services
             .AddHttpClient(RoutedClientWithRetry)
             .ConfigurePrimaryHttpMessageHandler(ConfigurePrimaryHttpMessageHandler)
-            .AddHttpMessageHandler<ProxyLoggingHandler>()
             .AddPolicyHandler(strategy);
     }
 
@@ -71,7 +69,6 @@ int httpClientRetryCount
 
         return services
             .AddHttpClient(CdsProxyClientWithRetry)
-            .AddHttpMessageHandler<ProxyLoggingHandler>()
             .ConfigurePrimaryHttpMessageHandler(ConfigurePrimaryHttpMessageHandler)
             .AddPolicyHandler(strategy);
     }
@@ -91,13 +88,36 @@ public static HttpClientHandler CreateHttpClientHandler(string? proxyUri)
 
     public static WebProxy CreateProxy(string? proxyUri)
     {
-        Log.Logger.Information("Proxy Uri from ENV: {ProxyUri}", proxyUri);
-        var proxy = new WebProxy { BypassProxyOnLocal = false };
+        var proxy = new WebProxy { BypassProxyOnLocal = true };
         if (proxyUri != null)
         {
-            proxy.Address = new Uri(proxyUri, UriKind.RelativeOrAbsolute);
+            ConfigureProxy(proxy, proxyUri);
         }
-        Log.Logger.Information("WebProxy.Address: {ProxyUri}", proxy.Address);
         return proxy;
     }
+
+    public static void ConfigureProxy(WebProxy proxy, string proxyUri)
+    {
+        var uri = new UriBuilder(proxyUri);
+
+        var credentials = GetCredentialsFromUri(uri);
+        if (credentials != null)
+        {
+            proxy.Credentials = credentials;
+        }
+
+        // Remove credentials from URI to so they don't get logged.
+        uri.UserName = "";
+        uri.Password = "";
+        proxy.Address = uri.Uri;
+    }
+
+    private static NetworkCredential? GetCredentialsFromUri(UriBuilder uri)
+    {
+        var username = uri.UserName;
+        var password = uri.Password;
+        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
+            return null;
+        return new NetworkCredential(username, password);
+    }
 }

BtmsGateway/Utils/Http/ProxyLoggingHandler.cs

@@ -1,8 +1,6 @@
 using BtmsGateway.Utils.Http;
 using FluentAssertions;
 
-namespace BtmsGateway.Test.Http;
-
 public class ProxyTest
 {
     private const string ProxyUri = "http://user:password@localhost:8080";
@@ -31,8 +29,8 @@ public void ProxyShouldBypassLocal()
     {
         var proxy = Proxy.CreateProxy(ProxyUri);
 
-        proxy.BypassProxyOnLocal.Should().BeFalse();
-        proxy.IsBypassed(new Uri(Localhost)).Should().BeFalse();
+        proxy.BypassProxyOnLocal.Should().BeTrue();
+        proxy.IsBypassed(new Uri(Localhost)).Should().BeTrue();
         proxy.IsBypassed(new Uri("https://defra.gov.uk")).Should().BeFalse();
     }
 
@@ -46,7 +44,7 @@ public void HandlerShouldHaveProxy()
         handler.Proxy?.Credentials.Should().BeNull();
         handler.Proxy?.GetProxy(new Uri(Localhost)).Should().NotBeNull();
         handler.Proxy?.GetProxy(new Uri("http://google.com")).Should().NotBeNull();
-        handler.Proxy?.GetProxy(new Uri(Localhost))?.AbsoluteUri.Should().Be(LocalProxy);
+        handler.Proxy?.GetProxy(new Uri(Localhost))?.AbsoluteUri.Should().Be(Localhost);
         handler.Proxy?.GetProxy(new Uri("http://google.com"))?.AbsoluteUri.Should().Be(LocalProxy);
     }
 }