use RFC 3339 for logging

[JosiahParry]

Using the json web api example the output for logging is non-standard.

✔ 03-01-2025 13:53:53 Listening on http://0.0.0.0:3000
✖ 03-01-2025 13:53:58 GET on / - Not found
✖ 03-01-2025 13:53:58 GET on /favicon.ico - Not found
✖ 03-01-2025 13:54:13 GET on /members/1 - Not found
✖ 03-01-2025 13:54:15 GET on /members/2 - Not found
ℹ 03-01-2025 13:54:28 GET on /api/members/2

It would be awesome if this followed the rfc 3339 (subset of iso 8601 for formatting) this would make it compatible with other tracing / logging format.

I would ideally like something like:

yyyy-mm-dd hh:mm:ss [log level] GET on / - Not found

So translating this:

2025-01-03 13:53:53 INFO ✔ Listening on http://0.0.0.0:3000
2025-01-03 13:53:58 ERROR ✖ GET on / - Not found
2025-01-03 13:53:58 ERROR ✖ GET on /favicon.ico - Not found
2025-01-03 13:54:13 ERROR ✖ GET on /members/1 - Not found
2025-01-03 13:54:15 ERROR ✖ GET on /members/2 - Not found
2025-01-03 13:54:28 INFO ℹ  GET on /api/members/2

[JohnCoene]

@JosiahParry do you know of an existing package that would do structured logging with formatted printing as you have suggest here? (thinking two birds with one stone)

[JosiahParry]

I am most familiar with this via tracing in the rust ecosystem which has a number of formatters for logging based on the use case https://docs.rs/tracing-subscriber/latest/tracing_subscriber/fmt/index.html.

The idea behind the provided formatters is actually quite nice and i wonder if there could be a global setting here for ambiorix as well—could lean on logger for this. tracing has 4 provided formatters:

• Full: human readable
• Compact: short line lengths
• Pretty: human readable not sensitive to storage
• Json: for integration into OpenTelemetry systems like prometheus and jaeger etc.

Here is the output from logging a hello world application in rust using the axum web framework and the default formatter (Full)

2025-01-04T19:15:24.576721Z DEBUG my_hands: listening on 127.0.0.1:3000
2025-01-04T19:15:27.654242Z TRACE axum::serve: connection 127.0.0.1:61377 accepted
2025-01-04T19:15:27.656231Z DEBUG request{method=GET uri=/ version=HTTP/1.1}: tower_http::trace::on_request: started processing request
2025-01-04T19:15:27.656380Z DEBUG request{method=GET uri=/ version=HTTP/1.1}: tower_http::trace::on_response: finished processing request latency=0 ms status=200

Code to recreate

src/main.rs

use axum::{response::Html, routing::get, Router};
use tokio::net::TcpListener;
use tower_http::trace::TraceLayer;
use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};

#[tokio::main]
async fn main() {
    // add basic tracing information
    let tracing_layer = tracing_subscriber::fmt::layer();
    tracing_subscriber::registry().with(tracing_layer).init();

    // add hello world route
    let app = Router::new()
        .route("/", get(handler))
        .layer(TraceLayer::new_for_http());

    // run web server
    let listener = TcpListener::bind("127.0.0.1:3000").await.unwrap();
    tracing::debug!("listening on {}", listener.local_addr().unwrap());
    axum::serve(listener, app).await.unwrap();
}

async fn handler() -> Html<&'static str> {
    Html("<h1>Hello, World!</h1>")
}

Cargo.toml

[package]
name = "my-hands"
version = "0.1.0"
edition = "2021"

[dependencies]
axum = { version = "0.8.1", features = ["tracing"] }
tokio = { version = "1.41.1", features = ["rt-multi-thread"] }
tower-http = { version = "0.6.2", features = ["trace"] }
tracing = "0.1.41"
tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }