Add support for enricher constructor dependency injection

[osudude]

In .NET core, Microsoft got rid of good old HttpContext.Current. You now have to get at it by injecting IHttpContextAccessor into your class constructor that needs to read various http header values. It would be nice if we could inject IHttpContextAccessor into our constructor for enriching values based upon the current http request context (yes, this is possible via middleware but P.I.T.A.). Enricher properties of interest would be various request headers and the user name for the current request.

[nblumhardt]

Thanks for the note. Perhaps this would fit under the https://github.com/serilog-web projects, somewhere?

So far, for .NET Core, middleware has been working pretty well, though - e.g. https://blog.getseq.net/smart-logging-middleware-for-asp-net-core/

[fish0185]

how about inject IServiceCollection

public class RequestIdEnricher : ILogEventEnricher
    {
        private readonly IHttpContextAccessor _httpContextAccessor;

        public RequestIdEnricher(IServiceCollection services)
        {
            var sp = services.BuildServiceProvider();
            _httpContextAccessor = sp.GetService<IHttpContextAccessor>();
        }

        public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
        {
            if (logEvent == null)
            {
                throw new ArgumentNullException("logEvent");
            }

            string correlationId = _httpContextAccessor?.HttpContext?.Request?.Headers["CorrelationId"];

            if (string.IsNullOrWhiteSpace(correlationId))
            {
                return;
            }

            var correlationIdProperty = new LogEventProperty("CorrelationId", new ScalarValue(correlationId));
            logEvent.AddPropertyIfAbsent(correlationIdProperty);
        }
    }

[NibblyPig]

Enrich.With<T> requires T to have a parameterless constructor, so you can't DI anything into it.

[nblumhardt]

@nblumhardt Enrich.With(new T(...)) is available, too, so you can pass parameters to the constructor of T using that method.

[nblumhardt]

Folks watching this thread, check out the IDiagnosticContext example in Request Logging over at the ASP.NET Core integration lib; not exactly what's being sought after here, but via middleware does do a good job of covering many cases. HTH!

[spottedmahn]

example in Request Logging over

updated link: Request Logging

[nblumhardt]

You can now ReadFrom.Services() and pass an IServiceCollection from which sinks/enrichers/filters may be resolved. Might not cover all cases here but has to be pretty close. HTH!