Serilog.Exceptions

Serilog.Exceptions is an add-on to Serilog to log exception details and custom properties that are not output in Exception.ToString().

What Does It Do?

Your JSON logs will now be supplemented with detailed exception information and even custom exception properties. Here is an example of what happens when you log a DbEntityValidationException from EntityFramework (This exception is notorious for having deeply nested custom properties which are not included in the .ToString()).

try
{
    ...
}
catch (DbEntityValidationException exception)
{
    logger.Error(exception, "Hello World");
}

The code above logs the following:

{
  "Timestamp": "2015-12-07T12:26:24.0557671+00:00",
  "Level": "Error",
  "MessageTemplate": "Hello World",
  "RenderedMessage": "Hello World",
  "Exception": "System.Data.Entity.Validation.DbEntityValidationException: Message",
  "Properties": {
    "ExceptionDetail": {
      "EntityValidationErrors": [
        {
          "Entry": null,
          "ValidationErrors": [
            {
              "PropertyName": "PropertyName",
              "ErrorMessage": "PropertyName is Required.",
              "Type": "System.Data.Entity.Validation.DbValidationError"
            }
          ],
          "IsValid": false,
          "Type": "System.Data.Entity.Validation.DbEntityValidationResult"
        }
      ],
      "Message": "Validation failed for one or more entities. See 'EntityValidationErrors' property for more details.",
      "Data": {},
      "InnerException": null,
      "TargetSite": null,
      "StackTrace": null,
      "HelpLink": null,
      "Source": null,
      "HResult": -2146232032,
      "Type": "System.Data.Entity.Validation.DbEntityValidationException"
    },
    "Source": "418169ff-e65f-456e-8b0d-42a0973c3577"
  }
}

Getting Started

Add the Serilog.Exceptions NuGet package to your project using the NuGet Package Manager or run the following command in the Package Console Window:

Install-Package Serilog.Exceptions

When setting up your logger, add the With.ExceptionDetails() line like so:

using Serilog;
using Serilog.Exceptions;

ILogger logger = new LoggerConfiguration()
    .Enrich.WithExceptionDetails()
    .WriteTo.RollingFile(
        new JsonFormatter(renderMessage: true), 
        @"C:\logs\log-{Date}.txt")    
    .CreateLogger();

Performance

This library has custom code to deal with extra properties on most common exception types and only falls back to using reflection to get the extra information if the exception is not supported by Serilog.Exceptions internally.

Custom Exception Destructurers

You may want to add support for destructuring your own exceptions without relying on reflection. To do this, create your own destructuring class implementing ExceptionDestructurer (You can take a look at this for ArgumentException), then simply add it like so:

using Serilog;
using Serilog.Exceptions;
using Serilog.Formatting.Json;

var exceptionDestructurers = new List<IExceptionDestructurer>();
exceptionDestructurers.AddRange(ExceptionEnricher.DefaultDestructurers);  // Add built in destructurers.
exceptionDestructurers.Add(new MyCustomExceptionDestructurer());          // Add your custom destructurer.

ILogger logger = new LoggerConfiguration()
    .Enrich.WithExceptionDetails(exceptionDestructurers)
    .WriteTo.RollingFile(
        new JsonFormatter(renderMessage: true), 
        @"C:\logs\log-{Date}.txt")    
    .CreateLogger();

If you write a destructurer that is not included in this project (even for a third party library), please contribute it.

Additional configuration

You can configure some additional properties of destructuring process, by passing custom destructuring options during setup:

.Enrich.WithExceptionDetails(new DestructuringOptionsBuilder().WithDefaultDestructurers().WithRootName("Exception"))

Currently following options are supported:

• RootName: property name which will hold destructured exception, ExceptionDetail by default
• Filter: object implementing IExceptionPropertyFilter that will have a chance to filter properties just before they are put in destructured exception object. Go to "Filtering properties" section for details.
• DestructuringDepth: maximum depth of reflection based recursive destructuring process

Filtering properties

You may want to skip some properties of all or part your exception classes without directly creating or modyfying custom destructurers. Serilog.Exceptions supports this functionality using filter.

Most typical use case is the need to skip StackTrace and TargetSite. Serilog is already reporting them so you may want Serilog.Exceptions to skip them to save space and processing time. To do that you just need to modify a line in configuration:

.Enrich.WithExceptionDetails(new DestructuringOptionsBuilder().WithFilter(someFilter));

Filtering for other scenarios is also supported:

• use WithIgnoreStackTraceAndTargetSiteExceptionFilter if you need to filter some other set of named properties
• implement custom IExceptionPropertyFilter if you need some different filtering logic
• use CompositeExceptionPropertyFilter to combine multiple filters

Contributing

Please look at the contributing guide.

Special Thanks

• krajek & JeroenDragt - For adding filters to help ignore exception properties you don't want logged.
• krajek - For helping with cyclic dependencies when using the reflection destructurer.
• mraming - For logging properties that throw exceptions.
• optical - For a huge VS 2017 upgrade PR.
• Jérémie Bertrand - For making Serilog.Exceptions compatible with Mono.
• krajek - For writing some much needed unit tests.