Add configurable HTTP status code log levels for HttpClientLogging

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/HttpStatusCodeLogLevelRule.cs

@@ -0,0 +1,46 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.Logging;
+using Microsoft.Shared.DiagnosticIds;
+
+namespace Microsoft.Extensions.Http.Logging;
+
+/// <summary>
+/// Maps a status code or range of status codes to a specific log level.
+/// </summary>
+[Experimental(diagnosticId: DiagnosticIds.Experiments.Telemetry, UrlFormat = DiagnosticIds.UrlFormat)]
+public class HttpStatusCodeLogLevelRule : IValidatableObject
+{
+    /// <summary>
+    /// Gets or sets the minimum status code this rule applies to (inclusive).
+    /// </summary>
+    [Range(100, 599)]
+    public int FromStatusCode { get; set; }
+
+    /// <summary>
+    /// Gets or sets the maximum status code this rule applies to (inclusive).
+    /// When <see langword="null"/>, matches only <see cref="FromStatusCode"/> (exact match).
+    /// </summary>
+    [Range(100, 599)]
+    public int? ToStatusCode { get; set; }
+
+    /// <summary>
+    /// Gets or sets the log level to use for responses matching this rule.
+    /// </summary>
+    public LogLevel LogLevel { get; set; } = LogLevel.Information;
+
+    /// <inheritdoc/>
+    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
+    {
+        if (ToStatusCode.HasValue && ToStatusCode.Value < FromStatusCode)
+        {
+            yield return new ValidationResult(
+                $"{nameof(ToStatusCode)} must be greater than or equal to {nameof(FromStatusCode)}.",
+                [nameof(ToStatusCode)]);
+        }
+    }
+}

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/Internal/HttpClientLogger.cs

@@ -31,6 +31,8 @@ internal sealed class HttpClientLogger : IHttpClientAsyncLogger
     private readonly bool _logResponseHeaders;
     private readonly bool _logRequestHeaders;
     private readonly bool _pathParametersRedactionSkipped;
+    private readonly IReadOnlyList<HttpStatusCodeLogLevelRule> _statusCodeLogLevelRules;
+    private readonly LogLevel _exceptionLogLevel;
     private ILogger<HttpClientLogger> _logger;
     private IHttpRequestReader _httpRequestReader;
     private IHttpClientLogEnricher[] _enrichers;
@@ -62,6 +64,10 @@ internal HttpClientLogger(
         _logResponseHeaders = options.ResponseHeadersDataClasses.Count > 0;
         _logRequestHeaders = options.RequestHeadersDataClasses.Count > 0;
         _pathParametersRedactionSkipped = options.RequestPathParameterRedactionMode == HttpRouteParameterRedactionMode.None;
+        _statusCodeLogLevelRules = options.StatusCodeLogLevelRules is { } rules
+            ? rules as IReadOnlyList<HttpStatusCodeLogLevelRule> ?? rules.ToArray()
+            : [];
+        _exceptionLogLevel = options.ExceptionLogLevel;
     }
 
     public async ValueTask<object?> LogRequestStartAsync(HttpRequestMessage request, CancellationToken cancellationToken = default)
@@ -133,11 +139,23 @@ public void LogRequestStop(object? context, HttpRequestMessage request, HttpResp
     public void LogRequestFailed(object? context, HttpRequestMessage request, HttpResponseMessage? response, Exception exception, TimeSpan elapsed)
         => throw new NotSupportedException(SyncLoggingExceptionMessage);
 
-    private static LogLevel GetLogLevel(LogRecord logRecord)
+    private LogLevel GetLogLevel(LogRecord logRecord)
     {
+        int statusCode = logRecord.StatusCode!.Value;
+
+        for (int i = 0; i < _statusCodeLogLevelRules.Count; i++)
+        {
+            var rule = _statusCodeLogLevelRules[i];
+            int to = rule.ToStatusCode ?? rule.FromStatusCode;
+
+            if (statusCode >= rule.FromStatusCode && statusCode <= to)
+            {
+                return rule.LogLevel;
+            }
+        }
+
         const int HttpErrorsRangeStart = 400;
         const int HttpErrorsRangeEnd = 599;
-        int statusCode = logRecord.StatusCode!.Value;
 
         if (statusCode >= HttpErrorsRangeStart && statusCode <= HttpErrorsRangeEnd)
         {
@@ -188,7 +206,7 @@ private async ValueTask LogResponseAsync(
             }
             else
             {
-                Log.OutgoingRequestError(_logger, logRecord, exception);
+                Log.OutgoingRequestError(_logger, _exceptionLogLevel, logRecord, exception);
             }
         }
         catch (Exception ex)

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/Internal/Log.cs

@@ -44,9 +44,9 @@ public static void OutgoingRequest(ILogger logger, LogLevel level, LogRecord rec
         OutgoingRequest(logger, level, 1, nameof(OutgoingRequest), record);
     }
 
-    public static void OutgoingRequestError(ILogger logger, LogRecord record, Exception exception)
+    public static void OutgoingRequestError(ILogger logger, LogLevel level, LogRecord record, Exception exception)
     {
-        OutgoingRequest(logger, LogLevel.Error, 2, nameof(OutgoingRequestError), record, exception);
+        OutgoingRequest(logger, level, 2, nameof(OutgoingRequestError), record, exception);
     }
 
     [LoggerMessage(LogLevel.Error, RequestReadErrorMessage)]

src/Libraries/Microsoft.Extensions.Http.Diagnostics/Logging/LoggingOptions.cs

@@ -7,6 +7,8 @@
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.Extensions.Compliance.Classification;
 using Microsoft.Extensions.Http.Diagnostics;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 using Microsoft.Shared.Data.Validation;
 using Microsoft.Shared.DiagnosticIds;
 
@@ -163,4 +165,27 @@ public class LoggingOptions
     /// </remarks>
     [Experimental(diagnosticId: DiagnosticIds.Experiments.Telemetry, UrlFormat = DiagnosticIds.UrlFormat)]
     public bool LogContentHeaders { get; set; }
+
+    /// <summary>
+    /// Gets or sets a list of rules that map HTTP status codes or ranges to specific log levels.
+    /// </summary>
+    /// <value>
+    /// The default value is an empty list. When empty, the built-in behavior applies: 400-599 logs at <see cref="Microsoft.Extensions.Logging.LogLevel.Error"/>,
+    /// all other status codes log at <see cref="Microsoft.Extensions.Logging.LogLevel.Information"/>.
+    /// </value>
+    /// <remarks>
+    /// Rules are evaluated in order; the first matching rule wins. If no rule matches, the built-in default applies.
+    /// </remarks>
+    [Experimental(diagnosticId: DiagnosticIds.Experiments.Telemetry, UrlFormat = DiagnosticIds.UrlFormat)]
+    [ValidateEnumeratedItems]
+    public IList<HttpStatusCodeLogLevelRule> StatusCodeLogLevelRules { get; set; } = [];
+
+    /// <summary>
+    /// Gets or sets the log level used when an HTTP request throws an exception.
+    /// </summary>
+    /// <value>
+    /// The default value is <see cref="Microsoft.Extensions.Logging.LogLevel.Error"/>.
+    /// </value>
+    [Experimental(diagnosticId: DiagnosticIds.Experiments.Telemetry, UrlFormat = DiagnosticIds.UrlFormat)]
+    public LogLevel ExceptionLogLevel { get; set; } = LogLevel.Error;
 }

test/Libraries/Microsoft.Extensions.Http.Diagnostics.Tests/Logging/HttpClientLoggerStatusCodeLogLevelTest.cs

@@ -0,0 +1,228 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Compliance.Classification;
+using Microsoft.Extensions.Http.Diagnostics;
+using Microsoft.Extensions.Http.Diagnostics.Test.Logging.Internal;
+using Microsoft.Extensions.Http.Logging.Internal;
+using Microsoft.Extensions.Http.Logging.Test.Internal;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Testing;
+using Microsoft.Extensions.Telemetry.Internal;
+using Moq;
+using Xunit;
+
+namespace Microsoft.Extensions.Http.Logging.Test;
+
+public class HttpClientLoggerStatusCodeLogLevelTest
+{
+    [Theory]
+    [InlineData(HttpStatusCode.NotFound, LogLevel.Warning)]
+    [InlineData(HttpStatusCode.BadRequest, LogLevel.Warning)]
+    [InlineData(HttpStatusCode.InternalServerError, LogLevel.Error)]
+    public async Task StatusCodeLogLevelRules_MatchesConfiguredRule(HttpStatusCode statusCode, LogLevel expectedLevel)
+    {
+        var options = new LoggingOptions
+        {
+            StatusCodeLogLevelRules =
+            [
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 400, ToStatusCode = 499, LogLevel = LogLevel.Warning },
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 500, ToStatusCode = 599, LogLevel = LogLevel.Error },
+            ]
+        };
+
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+        using var httpResponseMessage = new HttpResponseMessage(statusCode);
+
+        using var handler = CreateHandler(fakeLogger, options, httpResponseMessage);
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await client.SendAsync(httpRequestMessage, CancellationToken.None);
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(expectedLevel, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task StatusCodeLogLevelRules_FirstMatchWins()
+    {
+        var options = new LoggingOptions
+        {
+            StatusCodeLogLevelRules =
+            [
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 404, LogLevel = LogLevel.Debug },
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 400, ToStatusCode = 499, LogLevel = LogLevel.Warning },
+            ]
+        };
+
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+        using var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.NotFound);
+
+        using var handler = CreateHandler(fakeLogger, options, httpResponseMessage);
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await client.SendAsync(httpRequestMessage, CancellationToken.None);
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Debug, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task StatusCodeLogLevelRules_NoMatch_FallsBackToDefaultBehavior()
+    {
+        var options = new LoggingOptions
+        {
+            StatusCodeLogLevelRules =
+            [
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 404, LogLevel = LogLevel.Debug },
+            ]
+        };
+
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+        using var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.InternalServerError);
+
+        using var handler = CreateHandler(fakeLogger, options, httpResponseMessage);
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await client.SendAsync(httpRequestMessage, CancellationToken.None);
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Error, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task StatusCodeLogLevelRules_EmptyRules_UsesDefaultBehavior()
+    {
+        var options = new LoggingOptions();
+
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+        using var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.OK);
+
+        using var handler = CreateHandler(fakeLogger, options, httpResponseMessage);
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await client.SendAsync(httpRequestMessage, CancellationToken.None);
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Information, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task ExceptionLogLevel_UsesConfiguredLevel()
+    {
+        var options = new LoggingOptions
+        {
+            ExceptionLogLevel = LogLevel.Warning,
+        };
+
+        var exception = new HttpRequestException("test");
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+
+        using var handler = new TestLoggingHandler(
+            new HttpClientLogger(
+                fakeLogger,
+                Mock.Of<IHttpRequestReader>(),
+                [],
+                options),
+            new TestingHandlerStub((_, _) => throw exception));
+
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(httpRequestMessage, CancellationToken.None));
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Warning, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task ExceptionLogLevel_DefaultIsError()
+    {
+        var options = new LoggingOptions();
+
+        var exception = new HttpRequestException("test");
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+
+        using var handler = new TestLoggingHandler(
+            new HttpClientLogger(
+                fakeLogger,
+                Mock.Of<IHttpRequestReader>(),
+                [],
+                options),
+            new TestingHandlerStub((_, _) => throw exception));
+
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(httpRequestMessage, CancellationToken.None));
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Error, logRecord.Level);
+    }
+
+    [Fact]
+    public async Task StatusCodeLogLevelRules_ExactMatch_WithNullToStatusCode()
+    {
+        var options = new LoggingOptions
+        {
+            StatusCodeLogLevelRules =
+            [
+                new HttpStatusCodeLogLevelRule { FromStatusCode = 429, ToStatusCode = null, LogLevel = LogLevel.Warning },
+            ]
+        };
+
+        var fakeLogger = new FakeLogger<HttpClientLogger>();
+        using var httpResponseMessage = new HttpResponseMessage((HttpStatusCode)429);
+
+        using var handler = CreateHandler(fakeLogger, options, httpResponseMessage);
+        using var client = new HttpClient(handler);
+        using var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, "http://example.com/test");
+
+        await client.SendAsync(httpRequestMessage, CancellationToken.None);
+
+        var logRecords = fakeLogger.Collector.GetSnapshot();
+        var logRecord = Assert.Single(logRecords);
+        Assert.Equal(LogLevel.Warning, logRecord.Level);
+    }
+
+    private static TestLoggingHandler CreateHandler(
+        FakeLogger<HttpClientLogger> fakeLogger,
+        LoggingOptions options,
+        HttpResponseMessage response)
+    {
+        var mockHeadersRedactor = new Mock<IHttpHeadersRedactor>();
+        mockHeadersRedactor
+            .Setup(r => r.Redact(It.IsAny<IEnumerable<string>>(), It.IsAny<DataClassification>()))
+            .Returns("Redacted");
+
+        var headersReader = new HttpHeadersReader(options.ToOptionsMonitor(), mockHeadersRedactor.Object);
+
+        return new TestLoggingHandler(
+            new HttpClientLogger(
+                fakeLogger,
+                new HttpRequestReader(
+                    options,
+                    Mock.Of<IHttpRouteFormatter>(),
+                    Mock.Of<IHttpRouteParser>(),
+                    headersReader,
+                    Mock.Of<IOutgoingRequestContext>()),
+                [],
+                options),
+            new TestingHandlerStub((_, _) => Task.FromResult(response)));
+    }
+}