.NET 8 API中如何隐藏MSAL 4.64.0的False日志消息？

在.NET 8 API项目中，通过Serilog将日志输出至Application Insights时，每次请求都会生成大量包含「False MSAL 4.64.0.0 MSAL.NetCore .NET 8.0.8」的跟踪日志，需要隐藏这类日志。使用ITokenAcquisition获取后端服务令牌，已尝试以下两种配置但均未生效：

• 在appsettings.json的Logging节点将MSAL.NetCore设为Warning级别
• 在Serilog配置中添加ByExcluding过滤包含「False MSAL」的消息

相关代码与配置 #

获取令牌代码片段 #

accessToken = await _tokenAcquisition.GetAccessTokenForUserAsync(new[] { _configuration["PasApi:ScopeForAccessToken"] });

appsettings.json 原Logging配置 #

"Logging": {
  "LogLevel": {
     "Default": "Information",
     "Microsoft.AspNetCore": "Warning",
     "MSAL.NetCore": "Warning"
  }
}

原Serilog配置 #

"Serilog": {
  "MinimumLevel": {
    "Default": "Information",
    "Override": {
      "Microsoft": "Information",
      "Microsoft.AspNetCore": "Warning",
      "System": "Warning"
    }
  },
  "WriteTo": [
  {
    "Name": "ApplicationInsights",
    "Args": { 
       "telemetryConverter": "Serilog.Sinks.ApplicationInsights.TelemetryConverters.TraceTelemetryConverter, Serilog.Sinks.ApplicationInsights"
     }
  }
  ],
  "Filter": [
    {
      "Name": "ByExcluding",
      "Args": {
         "expression": "Contains(@MessageTemplate, 'False MSAL')"
      }
    }
  ]
},

示例日志 #

False MSAL 4.64.0.0 MSAL.NetCore .NET 8.0.8 Microsoft Windows 10.0.19045 [2024-09-17 09:57:46Z - 4671fb35-5f88-41a6-95f0-6b53f07cf66f] TokenEndpoint: ****

Program.cs 相关代码 #

builder.Host.UseSerilog((hostingContext, loggerConfiguration) => loggerConfiguration.ReadFrom.Configuration(hostingContext.Configuration));
builder.Services.AddAadRegistration(Configuration);

public static IServiceCollection AddAadRegistration(this IServiceCollection services, IConfiguration configuration)
{
  services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
        .AddMicrosoftIdentityWebApi(configuration.GetSection(AppSettings.AZUREAD))
        .EnableTokenAcquisitionToCallDownstreamApi()
        .AddInMemoryTokenCaches();

  services.Configure<JwtBearerOptions>(JwtBearerDefaults.AuthenticationScheme, options =>
  {
      options.TokenValidationParameters.NameClaimType = @"http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress";
  });

  var origins = new List<string>();
  configuration.Bind(AppSettings.CORS_MAIN, origins);

  services.AddCors(options =>
  {
      options.AddPolicy(name: Policies.CORS_MAIN,
        builder => builder.WithOrigins(origins.ToArray())
            .AllowAnyMethod()
            .AllowAnyHeader());
  });

  return services;
}

使用的NuGet包版本 #

• Azure.Identity v1.12.0
• Microsoft.AspNetCore.Authentication.JwtBearer v8.0.8
• Microsoft.Identity.Client 4.64.0
• Microsoft.Identity.Web 3.1.0
• Serilog.AspNetCore 8.0.2
• Serilog.Sinks.ApplicationInsights 4.0.0

1. 修正Serilog过滤表达式 #

原过滤规则针对@MessageTemplate，但这类日志的内容存储在@Message字段中，需修改过滤条件：

"Filter": [
  {
    "Name": "ByExcluding",
    "Args": {
       "expression": "Contains(@Message, 'False MSAL')"
    }
  }
]

若需更精准过滤（仅排除该内容的Info级日志），可使用：

"expression": "Contains(@Message, 'False MSAL') and @Level = 'Information'"

2. 正确配置MSAL日志级别 #

MSAL的日志类别是Microsoft.Identity.Client而非MSAL.NetCore，需更新日志级别配置：

方式一：在Serilog配置中添加Override #

"Serilog": {
  "MinimumLevel": {
    "Default": "Information",
    "Override": {
      "Microsoft": "Information",
      "Microsoft.AspNetCore": "Warning",
      "System": "Warning",
      "Microsoft.Identity.Client": "Warning" // 新增该行，将MSAL日志设为Warning
    }
  },
  // 其他配置保持不变
}

方式二：修改Logging节点配置 #

"Logging": {
  "LogLevel": {
     "Default": "Information",
     "Microsoft.AspNetCore": "Warning",
     "Microsoft.Identity.Client": "Warning" // 替换原MSAL.NetCore配置
  }
}

3. 验证效果 #

修改配置后重启项目，检查Application Insights的跟踪日志，确认「False MSAL」类日志已被过滤。

内容的提问来源于stack exchange，提问作者NiAu