SerilogWeb.Classic

Deprecation notice: this package is no longer maintained. The world has moved on to ASP.NET Core. Take a look at Serilog.AspNetCore instead!

Web request logging and enrichment for classic ASP.NET applications (System.Web).

Package - SerilogWeb.Classic | Platforms - .NET 4.5

This package replaces the Serilog.Extras.Web package previously included in the Serilog project.

This package is designed for full framework ASP.NET applications. For ASP.NET Core, have a look at Serilog.AspNetCore

When you work with an ASP.NET web application, this package adds

additional enrichers
an HttpModule to enhance the logging output.

When working with ASP.NET MVC (not Core) or ASP.NET Web API, you may also want to have a look at SerilogWeb.Classic.Mvc and SerilogWeb.Classic.WebAPI

Enrichers

The following enrichers are available as extension methods from the LoggerConfiguration.Enrich API:

WithClaimValue : adds a property contaning the value of a given claim from the current ClaimsIdentity User
WithHttpRequestClientHostIP : adds a property HttpRequestClientHostIP containing Request.UserHostAddress (optionally checking for proxy header)
WithHttpRequestClientHostName : adds a property HttpRequestClientHostName containing Request.UserHostName
WithHttpRequestId : adds a property HttpRequestId with a GUID used to identify requests.
WithHttpRequestNumber : adds a property HttpRequestNumber with an incrementing number per request.
WithHttpRequestRawUrl : adds a property HttpRequestRawUrl with the Raw Url of the Request.
WithHttpRequestTraceId : adds a property HttpRequestTraceId with a GUID matching the RequestTraceIdentifier assigned by IIS and used throughout ASP.NET/ETW. (IIS ETW tracing must be enabled for this to work)
WithHttpRequestType : adds a property HttpRequestType with the Request Type (GET or POST).
WithHttpRequestUrl : adds a property HttpRequestUrl with the Url of the Request.
WithHttpRequestUrlReferrer : adds a property HttpRequestUrlReferrer with the UrlReferrer of the Request.
WithHttpRequestUserAgent : adds a property HttpRequestUserAgent with the User Agent of the Request.
WithHttpSessionId : adds a property HttpSessionId with the current ASP.NET session id.
WithUserName : adds a property UserName with the current username or, when anonymous, a defined value. By default this is set to (anonymous).

var log = new LoggerConfiguration()
    .WriteTo.Console()
    .Enrich.WithHttpRequestId()
    .Enrich.WithUserName()
    .CreateLogger();

To override the username enricher behaviour:

var log = new LoggerConfiguration()
    .WriteTo.ColoredConsole()
    .Enrich.WithUserName("not known yet", System.Environment.UserName)
    .CreateLogger();

Enrichers can also be defined in a configuration file by using Serilog.Settings.AppSettings as follows:

<appSettings>
    <add key="serilog:using:SerilogWeb.Classic" value="SerilogWeb.Classic"/>
    <add key="serilog:enrich:WithClaimValue.claimProperty" value="MyClaimPropertyName"/>
    <add key="serilog:enrich:WithHttpRequestClientHostIP"/>
    <add key="serilog:enrich:WithHttpRequestClientHostName"/>
    <add key="serilog:enrich:WithHttpRequestId"/>
    <add key="serilog:enrich:WithHttpRequestNumber"/>
    <add key="serilog:enrich:WithHttpRequestRawUrl"/>
    <add key="serilog:enrich:WithHttpRequestTraceId"/>
    <add key="serilog:enrich:WithHttpRequestType"/>
    <add key="serilog:enrich:WithHttpRequestUrl"/>
    <add key="serilog:enrich:WithHttpRequestUrlReferrer"/>
    <add key="serilog:enrich:WithHttpRequestUserAgent"/>
    <add key="serilog:enrich:WithHttpSessionId"/>
    <add key="serilog:enrich:WithUserName"/>
</appSettings>

HttpModule

The ApplicationLifecycleModule Http module is automatically hooked up into your ASP.NET application as soon as you install the SerilogWeb.Classic package.

For each HTTP request that hits your application, this module will write log events containing information such as :

Url
Http Method
Response status code
Processing time

Regular events are written at Information level, and unhandled exceptions are captured and written at the Error level.

Optionally, form data that is posted to the server can also be captured.

The behavior of the Http module should fit most needs by default, but can be customized for finer control.

Fluent Configuration API

SerilogWeb.Classic v4.1 introduced a new fluent configuration API that is more discoverable and easier to test. The previous configuration mechanisms are still supported, but are considered obsolete and will be removed in a future major version.

All the configuration is done through method calls on SerilogWebClassic.Configure(cfg => cfg.xxx()).

By default, all requests will be logged at the Information level. To change this (i.e. to generate less events under normal conditions) use the LogAtLevel() method:

SerilogWebClassic.Configure(cfg => cfg
  .LogAtLevel(LogEventLevel.Debug)
);

(new in v5.1) If you want even more control, you can pass a callback to .LogAtLevel() and provide a Func<HttpContextBase, TimeSpan, LogEventLevel> like this :

SerilogWebClassic.Configure(cfg => cfg
  .LogAtLevel((context, elapsed) => elapsed.TotalMilliseconds > 3000 ? LogEventLevel.Warning : LogEventLevel.Information)
);

To enable the capture of posted form data:

SerilogWebClassic.Configure(cfg => cfg
  .EnableFormDataLogging()
);
// or
SerilogWebClassic.Configure(cfg => cfg
  .EnableFormDataLogging(forms => forms
    .OnlyOnError()
));
// or
SerilogWebClassic.Configure(cfg => cfg.
  .EnableFormDataLogging(forms => forms
    .OnMatch(ctx => !ctx.Request.Url.PathAndQuery.StartsWith("/__browserLink"))
));

Any fields containing the phrase 'password' will be filtered from the logged form data. This can be disabled with:

SerilogWebClassic.Configure(cfg => cfg
  .EnableFormDataLogging(forms => forms
    .DisablePasswordFiltering()
));

If you want to disable the logging completely, use the following statement:

SerilogWebClassic.Configure(cfg => cfg
  .Disable()
);

The configuration method calls are chainable, so a full configuration may look like :

SerilogWebClassic.Configure(cfg => cfg
  .UseLogger(myCustomLogger)
  .LogAtLevel(LogEventLevel.Debug)
  .IgnoreRequestsMatching(ctx => !ctx.Request.IsAuthenticated)
  .EnableFormDataLogging(forms => forms
    .AtLevel(LogEventLevel.Debug)
    .OnlyOnError()
    .FilterKeywords(new[] {"password", "authToken"} )
));

Legacy configuration

Before SerilogWeb.Classic v4.1, the configuration was done through static properties on ApplicationLifecycleModule class, as documented below.

This API is considered obsolete and may be removed in a future major version. Users should migrate to the newer fluent API documented above.

By default, all requests will be logged at the Information level. To change this (i.e. to generate less events under normal conditions) use the RequestLoggingLevel property:

ApplicationLifecycleModule.RequestLoggingLevel = LogEventLevel.Debug;

To enable the posting of form data:

ApplicationLifecycleModule.LogPostedFormData = LogPostedFormDataOption.Always;
// or
ApplicationLifecycleModule.LogPostedFormData = LogPostedFormDataOption.OnlyOnError;

Any fields containing the phrase 'password' will be filtered from the logged form data. This can be disabled with:

ApplicationLifecycleModule.FilterPasswordsInFormData = false;

If you want to disable the logging completely, use the following statement:

ApplicationLifecycleModule.IsEnabled = false;