Function layer 

pub fn layer(
    loki_url: Url,
    labels: HashMap<String, String>,
    extra_fields: HashMap<String, String>,
) -> Result<(Layer, BackgroundTask), Error>

Construct a Layer and its corresponding BackgroundTask.

The Layer needs to be registered with a tracing_subscriber::Registry, and the BackgroundTask needs to be tokio::spawned.

Note that unlike the Builder::build_url function, this function strips off the path component of loki_url before appending /loki/api/v1/push.

See builder() and this crate’s root documentation for a more flexible method.

Example

use tracing_subscriber::layer::SubscriberExt;
use tracing_subscriber::util::SubscriberInitExt;
use url::Url;

#[tokio::main]
async fn main() -> Result<(), tracing_loki::Error> {
    let (layer, task) = tracing_loki::layer(
        Url::parse("http://127.0.0.1:3100").unwrap(),
        vec![("host".into(), "mine".into())].into_iter().collect(),
        vec![].into_iter().collect(),
    )?;

    // We need to register our layer with `tracing`.
    tracing_subscriber::registry()
        .with(layer)
        // One could add more layers here, for example logging to stdout:
        // .with(tracing_subscriber::fmt::Layer::new())
        .init();

    // The background task needs to be spawned so the logs actually get
    // delivered.
    tokio::spawn(task);

    tracing::info!(
        task = "tracing_setup",
        result = "success",
        "tracing successfully set up",
    );

    Ok(())
}