Serilog logger using var logger doesn't output anything either on console or in file

Question

In .NET, I have following code

var logger =  new LoggerConfiguration()
                .Enrich.WithProperty("Assembly", assembly?.Name)
                .Enrich.FromLogContext()
                .MinimumLevel.Debug()
                .MinimumLevel.Override("Microsoft", LogEventLevel.Debug)
                .WriteTo.Console(
                    theme: Serilog.Sinks.SystemConsole.Themes.AnsiConsoleTheme.Code,
                    formatProvider: CultureInfo.CurrentCulture,
                    outputTemplate: "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff}][{Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}",
                    restrictedToMinimumLevel: LogEventLevel.Debug)
                .WriteTo.File(
                    path: "Logs/log-.log",
                    outputTemplate: "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff}][{Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}",
                    rollingInterval: RollingInterval.Day,
                    restrictedToMinimumLevel: LogEventLevel.Debug,
                    formatProvider: CultureInfo.CurrentCulture)
                .WriteTo.Sink(new WebSocketSink(logChannel), LogEventLevel.Debug)
                .WriteTo.Seq("http://localhost:5341")
                .CreateLogger();

When I pass this logger as argument to other classes where ILogger is used of Microsoft, the logging statements doesn't appear on console or in file. But when I change it to Log.logger = new LoggerConfiguration()..

logging statements starts appearing on console and in file as well.

Here is excerpt of class that I am using ILogger as argument

public class MyService(IDeviceIO devIO, ILogger<MyService> logger) : IMyService
{
    /// <inheritdoc/>
    public void OpenDevice(string host)
    {
        
        logger.LogInformation("Device is being opened!");
        devIO.Open(host);
    }
...

Why can't I use var logger = .. ? Do I need to use Log.logger which static instance always ?

Answer 1

I found out the problem. Added only three lines as follows and solved my problem

var logger = new LoggerConfiguration()
                .Enrich.WithProperty("Assembly", assembly?.Name)
                .Enrich.FromLogContext()
                .MinimumLevel.Debug()
                .MinimumLevel.Override("Microsoft", LogEventLevel.Debug)
                .WriteTo.Console(
                    theme: Serilog.Sinks.SystemConsole.Themes.AnsiConsoleTheme.Code,
                    formatProvider: CultureInfo.CurrentCulture,
                    outputTemplate: "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff}][{Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}",
                    restrictedToMinimumLevel: LogEventLevel.Debug)
                .WriteTo.File(
                    path: "Logs/log-.log",
                    outputTemplate: "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff}][{Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}",
                    rollingInterval: RollingInterval.Day,
                    restrictedToMinimumLevel: LogEventLevel.Debug,
                    formatProvider: CultureInfo.CurrentCulture)
                .WriteTo.Sink(new WebSocketSink(logChannel), LogEventLevel.Debug)
                .WriteTo.Seq("http://localhost:5341")
                .CreateLogger();
builder.Host.UseSerilog(logger);
builder.Services.AddLogging();

Thanks for help ! It was DI issue in short !