Serilog RollingFile

Question

I am trying to use WriteTo.RollingFile with Serilog as the following to write one file per day:

var log = new LoggerConfiguration().WriteTo.RollingFile(
                    @"F:\logs\log-{Date}.txt",
                    LogEventLevel.Debug).CreateLogger();
            log.Information("this is a log test");

But I am getting a new log file for each log entry during the same day!

How does one configure Serilog to write to a new file every day as to have a have a single log file per day?

---

And is there any archiving process to delete files older than 7 days?

Answer 1

Try below:

 var log = new LoggerConfiguration()
          .MinimumLevel.Debug()
          .WriteTo.File(@"f:\log\log.txt", rollingInterval: RollingInterval.Day) 
          .CreateLogger();

The log file name will be automatically log-20150819.txt etc. You do not need to specify the date.Old files will be cleaned up as per retainedFileCountLimit - default is 31.

Answer 2

WriteTo.RollingFile Deprecated

Since the posted answer, the method RollingFile is no longer viable and replaced with File and options to roll the logs.

Now one must use the standard Serilog.Sinks.File NuGet package which supports rolling:

.WriteTo.File(path: @"e:\logs\skilliam.log", 
              rollingInterval: RollingInterval.Day,
              rollOnFileSizeLimit: true, 
              fileSizeLimitBytes: 123456);

Answer 3

Here is a way to use Serilog with a web.config in an asp.net MVC 4/5 app.

In your web.config add the following:

<add key="serilog:minimum-level" value="Information" />
<add key="serilog:minimum-level:override:Microsoft" value="Information" />
<add key="serilog:minimum-level:override:System" value="Information" />
<add key="serilog:using:RollingFile" value="Serilog.Sinks.RollingFile" />
<add key="serilog:write-to:RollingFile.pathFormat" value="./Logs/log-{Date}.txt" />
<add key="serilog:write-to:RollingFile.outputTemplate" value="{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level}] [{SourceContext}] {Message}{NewLine}{Exception}" />
<add key="serilog:write-to:RollingFile.retainedFileCountLimit" value="10" />

Then in Application_Start of global.asax add the following:

// Get application base directory
string basedir = AppDomain.CurrentDomain.BaseDirectory;

// Setup Serilog for logging
Log.Logger = new LoggerConfiguration()
            .ReadFrom.AppSettings()
            .WriteTo.RollingFile(basedir + "/Logs/log-{Date}.txt")
            .CreateLogger();

Answer 4

To enable multi-process shared log files, set shared to true:

in code

.WriteTo.RollingFile("log-{Date}.txt", shared: true)

or in web.config

<add key="serilog:write-to:RollingFile.shared" value="true" />

Answer 5

To use the same file, you have to add shared: true

.WriteTo.RollingFile("log-{Date}.txt", shared: true)

Answer 6

As a follow up to this make sure you then use the globally scoped "Log" instance.

Example:

Log.Information("Hello world");

Answer 7

WriteTo.RollingFile Deprecated -> With Formatter

If one is using a text formatter ITextFormatter, note that the variable positions of the path has switched to be second place when using File.

So use this format with a formatter:

var filepath = @"C:\Logs";
ITextFormatter jsonFormatter = new Serilog.Formatting.Json.JsonFormatter(renderMessage: true);

...

Log.Logger = new LoggerConfiguration()
                  ... // Enrichers etc...
                 .WriteTo.File(formatter: jsonFormatter,
                               path: filepath,                            
                               rollingInterval: RollingInterval.Day,
                               rollOnFileSizeLimit: true, 
                               fileSizeLimitBytes: 123456,
                               shared: true)
                 .CreateLogger();

Answer 8

First of all. You need to add these nugets:

        <PackageReference Include="Serilog.AspNetCore" Version="6.1.0" />
        <PackageReference Include="Serilog.Enrichers.Environment" Version="2.2.0" />
        <PackageReference Include="Serilog.Enrichers.Process" Version="2.0.2" />
        <PackageReference Include="Serilog.Enrichers.Thread" Version="3.1.0" />
        <PackageReference Include="Serilog.Settings.Configuration" Version="3.4.0" />
        <PackageReference Include="Serilog.Sinks.File" Version="5.0.0" />

Than set your serilog in appsettings.json:

 "Serilog": {
    "Using": [
      "Serilog.Sinks.Console",
      "Serilog.Sinks.File"
    ],
    "MinimumLevel": {
      "Default": "Information"
    },
    "Enrich": [ "FromLogContext", "WithMachineName", "WithProcessId", "WithThreadId" ],
    "WriteTo": [
      {
        "Name": "Console"
      },
      {
        "Name": "File",
        "Args": {
          "Path": "../Logs/MyLog-.json",
          "RollingInterval": "Day",
          "formatter": "Serilog.Formatting.Json.JsonFormatter, Serilog"
        }
      },
      {
        "Name": "File",
        "Args": {
          "Path": "../Logs/MyLog-.log",
          "RollingInterval": "Day",
          "OutputTemplate": "[({Component}|{MachineName}|{ThreadId}) {Timestamp:G} [{Level:u3}]{Message:lj}{NewLine}{Exception} ]"
        }
      }
    ]
  }

Than you need to add this config in C# code.

var _logger = new LoggerConfiguration()
            .ReadFrom
            .Configuration(configuration)
            .Enrich
            .FromLogContext()
            .CreateLogger();
        services.AddLogging(logBuilder => logBuilder.AddSerilog(_logger));


configuration is an instance of IConfiguration, u will find builder.Configuration
services --> builder.Services

Answer 9

This is how I did it:

private readonly Serilog.ILogger _logger; //= Log.ForContext( "Name", "Weather" );

public WeatherForecastController() {
  string subPath = Path.Combine( DateTime.Now.ToString( "yyyy" ), DateTime.Now.ToString( "MM" ) ) + $"/{DateTime.Now.ToString("dd")}_Weather";
  _logger = Log.ForContext( "Name", subPath );
}

---

  .UseSerilog( ( hostingContext, loggerConfiguration ) => loggerConfiguration
    .ReadFrom.Configuration( hostingContext.Configuration )
    .Enrich.FromLogContext()
    .WriteTo.Console()
    .WriteTo.Map(
      "Name",
      "Request",
      ( name, wt ) => {
        if (name == "Request")
          wt.RollingFile( Path.Combine( $"{hostingContext.Configuration["LogPath"]}/{{Date}}-{name}.txt" ) );
        else
          wt.File( $"{hostingContext.Configuration["LogPath"]}/{name}.txt" );
      } )
  );