Unity . Interception . Serilog

by johanclasson

Automatic trace logging through Serilog that is instrumented by Unity.Interception.

( Crawled 35 minutes ago )

Unity.Interception.Serilog NuGet Status Build Status

Types which are registered to the Unity Container with the RegisterLoggedType extension method are decorated with a logging behavior. The logs which are produced contains information about the respective types method invocations such as execution time, arguments and result, and are persisted though the Serilog ILogger-adapter.

In addition, all logging through the configured ILogger instance are enriched with properties describing the environment where the logging event occurred.


Overview of Unity.Interception.Serilog


Install NuGet-packages

Install-Package Unity.Interception.Serilog -Pre
Install-Package Serilog.Sinks.Literate # Substitute this for your favorite Sink

Sample Application

public interface IDummy
    void DoStuff();

internal class Dummy : IDummy
    public void DoStuff() { }

internal class Program
    public static void Main(string[] args)
        using (var container = new UnityContainer())
                .ConfigureSerilog(c => c.MinimumLevel.Debug().WriteTo.LiterateConsole())
                .RegisterLoggedType<IDummy, Dummy>();

            var dummy = container.Resolve<IDummy>();
            dummy.DoStuff(); // Method call is logged
            container.Resolve<ILogger>().Information("Application finished"); // Event log example


The logging is set up by calling the ConfigureSerilog extension method on a container, and either pass in a LoggerConfiguration instance or use the overload with an Action parameter where the LoggerConfiguration is created for you.

The ConfigureSerilog method registers an ILogger instance in the container, so it's important that the LoggerConfiguration is configured before.

Thrown exceptions are logged as errors by default, but it is possible to configure a list of expected exceptions which are then logged as information instead.

It is also possible to ignore methods from being logged at all, by passing a list of MethodIdentifiers. As an alternative to configure ignored methods though ConfigureSerilog, you can use the IgnoreMember attribute. It is not only applicable to methods, but parameters as well.

The event level of logs can be set through the level parameter.

using Unity.Interception.Serilog;
var container = new UnityContainer();
var expectedExceptions = new[] {typeof (InvalidOperationException)};
var ignoredMethods = new[] { new MethodIdentifier(typeof(IMyType), nameof(IMyType.DoStuff)) };
var level = LogEventLevel.Information
    .ConfigureSerilog(c => c.WriteTo.Xyz(...), expectedExceptions, ignoredMethods, level);

In this example, the configuration of Serilog is made through c.WriteTo.Xyz(...) and has to be replaced with the sink that you would like to use. For example with Serilog.Sinks.Elasticsearch the configuration could be done by c.WriteTo.Elasticsearch("http://localhost:9200", "myindex-{0:yyyy.MM.dd}").

It is optional whether to pass the parameters expectedExceptions, ignoredMethods and level or not.

The event level of logs is set to Debug by default. You have to specify the minimum level on the LoggerConfiguration instance yourself. This means that if you do not specify the log level, only Error logs will be written to your sink since the Serilog's default minimum level is set to Information.

using Unity.Interception.Customization;
public interface IMyType
    void DoSecretStuff();

    void DoStuffWithSecretParameter(string username, [IgnoreMember] string password);

Type Registration

To enable logging for a certain type use one of the extension methods:

using Unity.Interception.Serilog;
var container = new UnityContainer();
    .RegisterLoggedType<IMyType, MyType>();
    .RegisterLoggedInstance<IMyType>(new MyType());


All logs that is made through the ILogger that is registered in the container are enriched with the properties that are mentioned in CommonProperties.cs.

Trace Logs

Except from the common properties, the following is also logged for trace logs:

  • SourceContext: Namespace and och type name
  • EventId: Method name.
  • Arguments: A list of argument names and values.
  • Result: The result, if the method produces such a thing.
  • Duration: The execution time in ms.
  • LogType: Is set to Trace. This is nice to have to distinguish trace logs from for example event logs.

Due to performance reasons, arguments and results are not serialized as objects, but captured with ToString().

The properties Exception och ExceptionType are included for logs for thrown exceptions.

Event Logs

There is no built in support for formating event logs like the trace logs. You will have to write your own helper for that. For example:

public static void Information<T>(
    this ILogger logger, string eventId,
    string messageTemplate, params object[] propertyValues)
    messageTemplate = "[{SourceContext}.{EventId}] " + messageTemplate;
        .ForContext("EventId", eventId)
        .ForContext("LogType", "Event")
        .Information(messageTemplate, propertyValues);

Serilog.Sinks.MSSqlServer Example

There is a TraceLog helper class that is useful together with the SQL Server sink. For example, you could configure Serilog like so:

var columnOptions = new ColumnOptions { AdditionalDataColumns = TraceLog.DataColumns };
columnOptions.Properties.ExcludeAdditionalProperties = true;
var container = new UnityContainer()
    .ConfigureSerilog(c => c.WriteTo.MSSqlServer(
        "Server=.;Database=SerilogTest;Trusted_Connection=True;", "Log",
        autoCreateSqlTable: true, columnOptions: columnOptions));