Struct rocket_prometheus::PrometheusMetrics

#[must_use = "must be attached and mounted to a Rocket instance"]pub struct PrometheusMetrics { /* fields omitted */ }

Fairing and Handler implementing request instrumentation.

By default this tracks two metrics:

• rocket_http_requests_total (labels: endpoint, method, status): the total number of HTTP requests handled by Rocket.
• rocket_http_requests_duration_seconds (labels: endpoint, method, status): the request duration for all HTTP requests handled by Rocket.

The 'rocket' prefix of these metrics can be changed by setting the ROCKET_PROMETHEUS_NAMESPACE environment variable.

Usage

Simply attach and mount a PrometheusMetrics instance to your Rocket app as for a normal fairing / handler:

use rocket_prometheus::PrometheusMetrics;

let prometheus = PrometheusMetrics::new();
rocket::ignite()
    .attach(prometheus.clone())
    .mount("/metrics", prometheus)
    .launch();

Metrics will then be available on the "/metrics" endpoint:

$ curl localhost:8000/metrics
# HELP rocket_http_requests_duration_seconds HTTP request duration in seconds for all requests
# TYPE rocket_http_requests_duration_seconds histogram
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.005"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.01"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.025"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.05"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.1"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.25"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="0.5"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="1"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="2.5"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="5"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="10"} 2
rocket_http_requests_duration_seconds_bucket{endpoint="/metrics",method="GET",status="200",le="+Inf"} 2
rocket_http_requests_duration_seconds_sum{endpoint="/metrics",method="GET",status="200"} 0.0011045669999999999
rocket_http_requests_duration_seconds_count{endpoint="/metrics",method="GET",status="200"} 2
# HELP rocket_http_requests_total Total number of HTTP requests
# TYPE rocket_http_requests_total counter
rocket_http_requests_total{endpoint="/metrics",method="GET",status="200"} 2

Implementations

impl PrometheusMetrics

pub fn registry(&self) -> &Registry

Get the registry used by this fairing.

You can use this to register further metrics, causing them to be exposed along with the default metrics on the PrometheusMetrics handler.

use once_cell::sync::Lazy;
use prometheus::{opts, IntCounter};
use rocket_prometheus::PrometheusMetrics;

static MY_COUNTER: Lazy<IntCounter> = Lazy::new(|| {
    IntCounter::new("my_counter", "A counter I use a lot")
        .expect("Could not create counter")
});

let prometheus = PrometheusMetrics::new();
prometheus.registry().register(Box::new(MY_COUNTER.clone()));

impl PrometheusMetrics

pub fn new() -> Self

Create a new PrometheusMetrics.

pub fn with_registry(registry: Registry) -> Self

Create a new PrometheusMetrics with a custom Registry.

Trait Implementations

impl Clone for PrometheusMetrics

fn clone(&self) -> PrometheusMetrics

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for PrometheusMetrics

fn default() -> Self

Returns the "default value" for a type.

impl Fairing for PrometheusMetrics

fn info(&self) -> Info

Returns an [Info] structure containing the name and [Kind] of this fairing. The name can be any arbitrary string. Kind must be an ord set of Kind variants.

fn on_request(&self, request: &mut Request, _: &Data)

The request callback.

fn on_response(&self, request: &Request, response: &mut Response)

The response callback.

fn on_attach(&self, rocket: Rocket) -> Result<Rocket, Rocket>

The attach callback. Returns Ok if launch should proceed and Err if launch should be aborted.

fn on_launch(&self, rocket: &Rocket)

The launch callback.

impl Handler for PrometheusMetrics

fn handle<'r>(&self, req: &'r Request, _: Data) -> Outcome<'r>

Called by Rocket when a Request with its associated Data should be handled by this handler.

impl Into<Vec<Route>> for PrometheusMetrics

fn into(self) -> Vec<Route>

Performs the conversion.