使用ILogger<>的BeginScope添加自定义属性不生效问题

尝试通过BeginScope给日志添加全局自定义属性，但输出的日志中看不到这些附加的Scope属性，仅显示结构化日志本身的内容。

代码示例 #

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder
    .Services
    .AddLogging(c => c.AddJsonConsole(y => y.JsonWriterOptions = new() { Indented = true }));

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}


var summaries = new[]
{
    "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
};

app.MapGet("/weatherforecast", async (ILogger<Program> logger) =>
    {
        var state = new Dictionary<string, object>()
        {
            { "CustPropOne", "123456-7890123" },
            { "CustPropTwo", "blah blah blah" },
            { "CustNumber", 12345 }
        };
        using (logger.BeginScope(state))
        {
            logger.LogInformation("API 1 {One}", 1);

            var forecast = Enumerable.Range(1, 5).Select(index =>
                    new WeatherForecast
                    (
                        DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
                        Random.Shared.Next(-20, 55),
                        summaries[Random.Shared.Next(summaries.Length)]
                    ))
                .ToArray();
            return forecast;
        }
    })
    .WithName("GetWeatherForecast")
    .WithOpenApi();

app.Run();

record WeatherForecast(DateOnly Date, int TemperatureC, string? Summary)
{
    public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);
}

实际输出 #

{
  "EventId": 0,
  "LogLevel": "Information",
  "Category": "Program",
  "Message": "API 1 1",
  "State": {
    "Message": "API 1 1",
    "One": 1,
    "{OriginalFormat}": "API 1 {One}"
  }
}

解决方法 #

问题出在JsonConsole日志提供器的默认配置：默认不包含Scope信息，需要显式开启。

修改AddJsonConsole的配置，添加IncludeScopes = true：

builder
    .Services
    .AddLogging(c => c.AddJsonConsole(y => 
    {
        y.JsonWriterOptions = new() { Indented = true };
        // 开启Scope包含
        y.IncludeScopes = true;
    }));

修改后，日志输出会新增Scope字段，包含所有自定义属性：

{
  "EventId": 0,
  "LogLevel": "Information",
  "Category": "Program",
  "Message": "API 1 1",
  "State": {
    "Message": "API 1 1",
    "One": 1,
    "{OriginalFormat}": "API 1 {One}"
  },
  "Scope": [
    {
      "CustPropOne": "123456-7890123",
      "CustPropTwo": "blah blah blah",
      "CustNumber": 12345
    }
  ]
}

如果需要将Scope属性合并到State或根对象中，可以进一步配置JsonConsoleFormatterOptions自定义Scope格式化逻辑，但默认的单独Scope字段已经能清晰区分日志本身属性和全局Scope属性，满足多数场景需求。

内容的提问来源于stack exchange，提问作者Dario Griffo