Prometheus metrics for axum

Prometheus metrics for axum web applications.

This crate is similar to:

features:

The metrics are exposed given a certain namespace that you define
The requests to the metrics endpoint are not taken into account in the exposed metrics. (You can change this behavior by setting the endpoint to None)
By default, two metrics are recorded:
- the number of requests (as counter)
- the requests` durations (as histogram)

Example

copy/paste from simple example

use axum::{
    routing::get,
    Router,
};
use axum::extract::Path;
use axum_prom::PrometheusMetricsBuilder;

async fn hello(Path(name): Path<String>) -> String {
    format!("Hello {}!", name)
}

#[tokio::main]
async fn main() {
    let (prometheus, prometheus_registry) = PrometheusMetricsBuilder::new("myapp").pair().unwrap();

    // possibility to register your own metrics in `&prometheus_registry.registry`

    let app = Router::new()
        .route("/", get(|| async { "Hello, World!" }))
        .route("/hello/:name", get(hello))
        .route(
            axum_prom::DEFAULT_ENDPOINT,
            get(|| async move { prometheus_registry.metrics() }),
        )
        .layer(prometheus);

    // run it with hyper on localhost:3000
    let listener = tokio::net::TcpListener::bind("0.0.0.0:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

$ cargo run --example simple

# send a request to /
$ curl localhost:3000
Hello, World!

# send 2 requests to "/hello/:name"
$ curl localhost:3000/hello/you
Hello you!

$ curl localhost:3000/hello/universe
Hello universe!

# The metrics contains data for 2 endpoints: "/" and "/hello/:name"
$ curl localhost:3000/metrics
# HELP myapp_http_requests_duration_seconds HTTP request duration in seconds for all requests
# TYPE myapp_http_requests_duration_seconds histogram
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.005"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.01"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.025"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.05"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.1"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.25"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="0.5"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="1"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="2.5"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="5"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="10"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/",method="GET",status="200",le="+Inf"} 1
myapp_http_requests_duration_seconds_sum{endpoint="/",method="GET",status="200"} 0.000081435
myapp_http_requests_duration_seconds_count{endpoint="/",method="GET",status="200"} 1
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.005"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.01"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.025"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.05"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.1"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.25"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="0.5"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="1"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="2.5"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="5"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="10"} 2
myapp_http_requests_duration_seconds_bucket{endpoint="/hello/:name",method="GET",status="200",le="+Inf"} 2
myapp_http_requests_duration_seconds_sum{endpoint="/hello/:name",method="GET",status="200"} 0.000136117
myapp_http_requests_duration_seconds_count{endpoint="/hello/:name",method="GET",status="200"} 2
# HELP myapp_http_requests_total Total number of HTTP requests
# TYPE myapp_http_requests_total counter
myapp_http_requests_total{endpoint="/",method="GET",status="200"} 1
myapp_http_requests_total{endpoint="/hello/:name",method="GET",status="200"} 2

yanns/axum-prom

Prometheus metrics for axum

features:

Example