Simultaneous logging

[TornaxO7]

Hello! I've got a question: Is it possible to log to multiple sources at the "same" time? For example: I'd like to log to a file but also to journald as well, is that possible with tracing?

[davidbarsky]

Yes, take a look at this example. To adopt it to your use-case, replace the fmt::Layer() on line 18 with tracing_journald::Layer::Layer. The code will look something like this:

use std::io;
use tracing_subscriber::{fmt, layer::SubscriberExt, EnvFilter};

fn main() {
    let file_appender = tracing_appender::rolling::hourly(dir, "example.log");
    let (non_blocking, _guard) = tracing_appender::non_blocking(file_appender);

    let subscriber = tracing_subscriber::registry()
        .with(EnvFilter::from_default_env().add_directive(tracing::Level::TRACE.into()))
        .with(tracing_journald::Layer::new())
        .with(fmt::Layer::new().with_writer(non_blocking));
    tracing::subscriber::set_global_default(subscriber).expect("Unable to set a global subscriber");
}

[TornaxO7]

Awesome! Thank you for the verification! c(^-^)c