如何统一在Serilog推送上下文添加自定义数据适配不同日志源？

我在为Web API配置日志时遇到一个问题：需要在日志中记录自定义的ChannelId字段，但当前不同的SourceContext必须用不同的方式推送数据：

• 当SourceContext为Serilog.AspNetCore.RequestLoggingMiddleware时，需要用_diagnosticContext.Set("ChannelId", request.Channel)
• 通用日志或HttpClient日志场景，需要用LogContext.PushProperty("ChannelId", request.Channel)
• 当SourceContext为Microsoft.AspNetCore.HttpLogging.HttpLoggingMiddleware时，得先把值存到HttpContext.Items，再通过拦截器读取

现有日志配置如下：

Program.cs 初始化代码 #

Log.Logger = new Serilog.LoggerConfiguration()
            .CreateBootstrapLogger();

服务注册阶段 #

services.AddHttpContextAccessor();

services.AddHttpLogging(o =>
{
    o.CombineLogs = true;
    o.LoggingFields = HttpLoggingFields.All;   
    o.ResponseHeaders.Remove("Content-Type");
    o.ResponseHeaders.Remove("Accept");
    o.RequestHeaders.Remove("Content-Type");
    o.RequestHeaders.Remove("Accept");
    o.RequestBodyLogLimit = 8096;
    o.ResponseBodyLogLimit = 8096;
});

services.AddHttpLoggingInterceptor<SampleHttpLoggingInterceptor>();

var columnOptions = new ColumnOptions
{
    AdditionalDataColumns = new List<DataColumn>
    {
        new DataColumn("CorrelationId", typeof(string)),
        new DataColumn("TraceId", typeof(string)),
        new DataColumn("SpanId", typeof(string)),
        new DataColumn("ChannelId", typeof(string)),
        new DataColumn("RequestPath", typeof(string)),
        new DataColumn("Duration", typeof(decimal)),
        new DataColumn("SourceContext", typeof(string)),
    }
};

columnOptions.Store.Remove(StandardColumn.Properties);

services.AddSerilog((services, lc) => lc
    .ReadFrom.Configuration(config)
    .ReadFrom.Services(services)

    .MinimumLevel.Override("Microsoft.Hosting.Lifetime", LogEventLevel.Warning)
    .MinimumLevel.Override("Microsoft.AspNetCore.Hosting", LogEventLevel.Warning)
    .MinimumLevel.Override("Microsoft.AspNetCore.Mvc", LogEventLevel.Warning)
    .MinimumLevel.Override("Microsoft.AspNetCore.Routing", LogEventLevel.Warning)
    .MinimumLevel.Override("System.Net.Http.HttpClient.X", LogEventLevel.Warning)
    .MinimumLevel.Override("Polly", LogEventLevel.Warning)

    .Enrich.FromLogContext()
    .Enrich.WithProperty("ChannelId", string.Empty)
    .Enrich.WithProperty("Duration", string.Empty)
    .Enrich.WithClientIp()
    .Enrich.WithCorrelationId("CorrelationIdHeader", addValueIfHeaderAbsence: true)                
    .Enrich.WithSpan()

    .WriteTo.Conditional(
        _ => isDeveloment,
            wt => wt.Console(theme: AnsiConsoleTheme.Code          
        )
    )
    
    .WriteTo.Oracle(cfg =>
        cfg.WithSettings(
                "User Id=...", 
                tableSpaceAndTableName: "LogTable",
                tableSpaceAndFunctionName: string.Empty, columnOptions: columnOptions                            
            )
            .UseBurstBatch()                        
            .CreateSink(), 
            restrictedToMinimumLevel: LogEventLevel.Information
        )
     );

中间件配置 #

app.UseHttpLogging();

app.UseSerilogRequestLogging(options =>
{
       options.IncludeQueryInRequestPath = true;
});

当前为了填充ChannelId，我需要在控制器动作中写重复代码，还得用拦截器处理微软的HttpLoggingMiddleware，想找一种统一的方式来推送自定义数据，最好能去掉拦截器。

方案1：全局请求中间件 + LogContext（推荐） #

通过自定义中间件，在请求开始时就将ChannelId推入LogContext，这样所有基于Serilog的日志（包括RequestLogging、普通日志、HttpClient日志）都会自动带上这个属性；同时针对微软的HttpLoggingMiddleware，通过自定义enricher从HttpContext读取该值，避免使用拦截器。

步骤1：创建全局中间件

public class ChannelIdLoggingMiddleware
{
    private readonly RequestDelegate _next;

    public ChannelIdLoggingMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        // 从请求中获取ChannelId，示例从Header读取，可替换为你的业务逻辑
        var channelId = context.Request.Headers.TryGetValue("X-Channel-Id", out var value) 
            ? value.ToString() 
            : string.Empty;

        // 推入LogContext，作用域覆盖整个请求生命周期
        using (LogContext.PushProperty("ChannelId", channelId))
        {
            // 将值存入HttpContext，供微软HttpLoggingMiddleware读取
            context.Items["ChannelId"] = channelId;
            await _next(context);
        }
    }
}

步骤2：注册中间件（放在UseRouting之前）

app.UseMiddleware<ChannelIdLoggingMiddleware>();

app.UseRouting();
// 其他中间件...
app.UseHttpLogging();
app.UseSerilogRequestLogging(options =>
{
    options.IncludeQueryInRequestPath = true;
});

步骤3：自定义Enricher处理微软HttpLogging日志

创建enricher从HttpContext读取ChannelId并注入日志事件：

public class ChannelIdEnricher : ILogEventEnricher
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    public ChannelIdEnricher(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
    {
        var httpContext = _httpContextAccessor.HttpContext;
        if (httpContext?.Items.TryGetValue("ChannelId", out var channelId) == true)
        {
            logEvent.AddOrUpdateProperty(propertyFactory.CreateProperty("ChannelId", channelId.ToString()));
        }
    }
}

步骤4：在Serilog配置中添加该Enricher

修改Serilog注册代码，加入自定义enricher：

services.AddSerilog((services, lc) => lc
    // ... 其他原有配置
    .Enrich.FromLogContext()
    .Enrich.With<ChannelIdEnricher>() // 添加此行
    .Enrich.WithProperty("ChannelId", string.Empty)
    // ... 其他原有配置
);

此方案下，所有日志场景都会自动带上ChannelId，无需在控制器中写重复代码，也不需要拦截器。

方案2：完全替换微软HttpLoggingMiddleware，只用Serilog RequestLogging #

如果不需要微软HttpLoggingMiddleware的特定功能，可直接移除它，统一用Serilog的RequestLogging处理请求日志，这样所有请求日志都归Serilog管理，仅需维护一套属性推送逻辑。

步骤1：移除微软HttpLogging相关配置

删除以下代码：

services.AddHttpLogging(o => { ... });
services.AddHttpLoggingInterceptor<SampleHttpLoggingInterceptor>();
app.UseHttpLogging();

步骤2：增强Serilog RequestLogging

在Serilog RequestLogging中直接注入ChannelId：

app.UseSerilogRequestLogging(options =>
{
    options.IncludeQueryInRequestPath = true;
    options.EnrichDiagnosticContext = (diagnosticContext, httpContext) =>
    {
        var channelId = httpContext.Request.Headers["X-Channel-Id"].ToString();
        diagnosticContext.Set("ChannelId", channelId);
    };
});

这种方式更简洁，减少日志源数量，所有请求日志通过Serilog统一处理。

方案3：Serilog动态属性注入（适合简单场景） #

无需编写中间件，直接在Serilog配置中通过工厂方法从HttpContextAccessor动态获取ChannelId：

services.AddSerilog((services, lc) => lc
    // ... 其他原有配置
    .Enrich.FromLogContext()
    .Enrich.WithProperty("ChannelId", () => 
    {
        var httpContextAccessor = services.GetRequiredService<IHttpContextAccessor>();
        var httpContext = httpContextAccessor.HttpContext;
        if (httpContext == null) return string.Empty;
        return httpContext.Request.Headers.TryGetValue("X-Channel-Id", out var value) 
            ? value.ToString() 
            : string.Empty;
    })
    // ... 其他原有配置
);

注意：非请求场景下HttpContext可能为null，需做空值处理。

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