Serilog - multiple log files

Question

I am using Serilog for logging and cant' figure out how to separate log events to different files. For example, I want to log errors to error_log-ddmmyyyy.txt and warnings to warn_log-ddmmyyyy.txt.

Here goes my logger configuration:

Log.Logger = new LoggerConfiguration()             .WriteTo.Logger(lc =>                 lc.Filter.ByIncludingOnly(Matching.WithProperty("Level", "Warning"))                     .WriteTo.RollingFile(                         Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"Logs\warn_log-{Date}.txt"),                         outputTemplate: OutputTemplate))             .WriteTo.Logger(lc =>                 lc.Filter.ByIncludingOnly(Matching.WithProperty("Level", "Error"))                     .WriteTo.RollingFile(                         Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"Logs\error_log-{Date}.txt"),                         outputTemplate: OutputTemplate))             .CreateLogger(); 

It only works when I specify {Level} property exatcly in log message.

I was trying to use:

Matching.WithProperty<LogEventLevel>("Level", l => l == LogEventLevel.Warning) 

but it didn't work too.

Answer 1

I use the following configuration and it works for me:

            Log.Logger = new LoggerConfiguration()                     .MinimumLevel.Debug()                     .WriteTo.LiterateConsole()                     .WriteTo.Logger(l => l.Filter.ByIncludingOnly(e => e.Level == LogEventLevel.Information).WriteTo.RollingFile(@"Logs\Info-{Date}.log"))                     .WriteTo.Logger(l => l.Filter.ByIncludingOnly(e => e.Level == LogEventLevel.Debug      ).WriteTo.RollingFile(@"Logs\Debug-{Date}.log"))                     .WriteTo.Logger(l => l.Filter.ByIncludingOnly(e => e.Level == LogEventLevel.Warning    ).WriteTo.RollingFile(@"Logs\Warning-{Date}.log"))                     .WriteTo.Logger(l => l.Filter.ByIncludingOnly(e => e.Level == LogEventLevel.Error      ).WriteTo.RollingFile(@"Logs\Error-{Date}.log"))                     .WriteTo.Logger(l => l.Filter.ByIncludingOnly(e => e.Level == LogEventLevel.Fatal      ).WriteTo.RollingFile(@"Logs\Fatal-{Date}.log"))                     .WriteTo.RollingFile(@"Logs\Verbose-{Date}.log")                     .CreateLogger(); 

Answer 2

I think you need:

.ByIncludingOnly(evt => evt.Level == LogEventLevel.Warning) 

Edit:

In many cases it's now more succinct to use Serilog.Sinks.Map. With it, the example can be written as:

Log.Logger = new LoggerConfiuration()     .WriteTo.Map(         evt => evt.Level,         (level, wt) => wt.RollingFile("Logs\\" + level + "-{Date}.log"))     .CreateLogger();