Demo of using Serilog in .Net 9

This repository is to act as a learning tool and demo for Serilog and logging in general.

This should (hoepfully) cover most normal topics and use-cases.

Registering Serilog for use

There's actually multiple ways to register serilog. Depending on the intention:

• Only Log Provider
• As 1 of N Log Providers

Serilog as the sole log provider at runtime.

This is the normal and intended use-case for serilog. Generally speaking, you should be using Serilog.Sinks to log to different places as their equivalent.

Confusingly, this two ways to do this at the moment.

If you're working in web app and are using WebApplication.CreateBuilder then you have access to IHostBuilder via builder.Host:

var builder = WebApplication.CreateBuilder(args);

builder.Host.UseSerilog((host, lc) => lc
    .ReadFrom.Configuration(builder.Configuration));

If you don't have access to IHostBuilder, such as a non-web app, then you need to do the following:

var builder = Host.CreateApplicationBuilder();

builder.Services.AddSerilog((lc) => lc
     .ReadFrom.Configuration(builder.Configuration));

Note, however, that the latter is actually an extension on IServiceCollection and can thus be called in both cases. Furthermore, the first example is just a thin wrapper over it.

This is why it's the new default in the documentation/examples.

See:

• GitHub Issue: UseSerilog support for .net 7 CreateApplicationBuilder and HostApplicationBuilder
• GitHub Issue: UseSerilog support for .net8 IHostApplicationBuilder

Source code:

• IHostBuilder.UseSerilog
• IServiceCollection.AddSerilog

Serilog as one of N log providers

This is a more abnormal setup, but may come up if a ready Serilog.Sink does not exist for the service you wish to send logs to, but does have docs on registering a log provider.

For instance, if you want to capture logs with Application Insights.

builder.Logging.AddApplicationInsights(
        configureTelemetryConfiguration: (config) => 
            config.ConnectionString = builder.Configuration.GetConnectionString("APPLICATIONINSIGHTS_CONNECTION_STRING"),
            configureApplicationInsightsLoggerOptions: (options) => { }
    );

In this case, you'd register Serilog via:

builder.Logging.AddSerilog(
    new LoggerConfiguration()
        .ReadFrom.Configuration(builder.Configuration)
        .CreateLogger()
    );