How to change log level in F# Saturn Framework?

Question

When I run my Saturn app, I see some logs being written to the console.

Looks like they start with the LogLevel.Info. How do I engage more detailed logging, i.e. how to properly set e.g. LogLevel.Trace?

Answer 1

A way to go is setting logging in the Saturn app builder:

let app = application {
    pipe_through endpointPipe

    router topRouter
    url "http://0.0.0.0:8085/"
    memory_cache
    use_static "static"
    use_gzip
    logging configureLogging
}

And you can do configuration like this:

let configureLogging (logging: ILoggingBuilder) =
    logging.SetMinimumLevel(LogLevel.Trace) |> ignore

The only Saturn example I found is here, in the Saturn samples. There are more for ASP.NET Core, on top of which Saturn is built.

The default log level is indeed LogLevel.Info:

If you don't explicitly set the minimum level, the default value is Information, which means that Trace and Debug logs are ignored.

Remember not to set LogLevel.Trace for production:

These messages may contain sensitive application data. These messages are disabled by default and should never be enabled in a production environment.