Merge pull request #13 from sd2k/add-with_default_registry-fn

Add 'PrometheusMetrics::with_default_registry' associated function
sd2k · Jul 10, 2021 · 218fd14 · 218fd14
2 parents e6e63c4 + ae25cdf
commit 218fd14
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Use `Duration::as_secs_f64` instead of manually calculating nanoseconds when calculating request durations. This bumps the minimum supported Rust version to 1.38.0, which is unlikely to be a problem in practice, since Rocket still requires a nightly version of Rust.
 - Impl `From<PrometheusMetrics> for Vec<Route>` instead of `Into<Vec<Route>> for PrometheusMetrics`, since the former gives us the latter for free.
 - `PrometheusMetrics::registry` is now a `const fn`.
+- Add `PrometheusMetrics::with_default_registry` associated function, which creates a new `PrometheusMetrics` using the default global `prometheus::Registry` and will therefore expose metrics created by the various macros in the `prometheus` crate.
 
 ## [0.7.0] - 2020-06-19
 ### Changed

diff --git a/src/lib.rs b/src/lib.rs
@@ -226,6 +226,14 @@ impl PrometheusMetrics {
         Self::with_registry(Registry::new())
     }
 
+    /// Create a new `PrometheusMetrics` using the default Prometheus `Registry`.
+    ///
+    /// This will cause the fairing to include metrics created by the various
+    /// `prometheus` macros, e.g.  `register_int_counter`.
+    pub fn with_default_registry() -> Self {
+        Self::with_registry(prometheus::default_registry().clone())
+    }
+
     /// Create a new `PrometheusMetrics` with a custom `Registry`.
     pub fn with_registry(registry: Registry) -> Self {
         let namespace = env::var(NAMESPACE_ENV_VAR).unwrap_or_else(|_| "rocket".into());

diff --git a/tests/default_registry.rs b/tests/default_registry.rs
@@ -0,0 +1,121 @@
+#![feature(proc_macro_hygiene, decl_macro)]
+
+#[macro_use]
+extern crate rocket;
+
+use once_cell::sync::Lazy;
+use prometheus::{register_int_counter_vec, IntCounterVec};
+use rocket::{http::ContentType, local::Client};
+use rocket_prometheus::PrometheusMetrics;
+use serde_json::json;
+
+static NAME_COUNTER: Lazy<IntCounterVec> = Lazy::new(|| {
+    register_int_counter_vec!("name_counter", "Count of names", &["name"])
+        .expect("Could not create name_counter")
+});
+
+mod routes {
+    use rocket::http::RawStr;
+    use rocket_contrib::json::Json;
+    use serde::Deserialize;
+
+    use super::NAME_COUNTER;
+
+    #[get("/hello/<name>?<caps>")]
+    pub fn hello(name: &RawStr, caps: Option<bool>) -> String {
+        NAME_COUNTER.with_label_values(&[name]).inc();
+        let name = caps
+            .unwrap_or_default()
+            .then(|| name.to_uppercase())
+            .unwrap_or_else(|| name.to_string());
+        format!("Hello, {}!", name)
+    }
+
+    #[derive(Deserialize)]
+    pub struct Person {
+        age: u8,
+    }
+
+    #[post("/hello/<name>?<caps>", format = "json", data = "<person>")]
+    pub fn hello_post(name: String, person: Json<Person>, caps: Option<bool>) -> String {
+        let name = caps
+            .unwrap_or_default()
+            .then(|| name.to_uppercase())
+            .unwrap_or_else(|| name.to_string());
+        format!("Hello, {} year old named {}!", person.age, name)
+    }
+}
+
+#[test]
+fn main() {
+    let prometheus = PrometheusMetrics::new();
+    prometheus
+        .registry()
+        .register(Box::new(NAME_COUNTER.clone()))
+        .unwrap();
+    let rocket = rocket::ignite()
+        .attach(prometheus.clone())
+        .mount("/", routes![routes::hello, routes::hello_post])
+        .mount("/metrics", prometheus);
+    let client = Client::new(rocket).expect("valid rocket instance");
+    client.get("/hello/foo").dispatch();
+    client.get("/hello/foo").dispatch();
+    client.get("/hello/bar").dispatch();
+    client
+        .post("/hello/bar")
+        .header(ContentType::JSON)
+        .body(serde_json::to_string(&json!({"age": 50})).unwrap())
+        .dispatch();
+    let mut metrics = client.get("/metrics").dispatch();
+    let response = metrics.body_string().unwrap();
+    assert_eq!(
+        response
+            .lines()
+            .enumerate()
+            .filter_map(|(i, line)|
+            // Skip out the 'sum' lines since they depend on request duration.
+            if i != 18 && i != 32 {
+                Some(line)
+            } else {
+                None
+            })
+            .collect::<Vec<&str>>()
+            .join("\n"),
+        r#"# HELP name_counter Count of names
+# TYPE name_counter counter
+name_counter{name="bar"} 1
+name_counter{name="foo"} 2
+# 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="/hello/<name>?<caps>",method="GET",status="200",le="0.005"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.01"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.025"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.05"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.1"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.25"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="0.5"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="1"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="2.5"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="5"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="10"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="GET",status="200",le="+Inf"} 3
+rocket_http_requests_duration_seconds_count{endpoint="/hello/<name>?<caps>",method="GET",status="200"} 3
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.005"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.01"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.025"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.05"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.1"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.25"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="0.5"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="1"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="2.5"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="5"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="10"} 1
+rocket_http_requests_duration_seconds_bucket{endpoint="/hello/<name>?<caps>",method="POST",status="200",le="+Inf"} 1
+rocket_http_requests_duration_seconds_count{endpoint="/hello/<name>?<caps>",method="POST",status="200"} 1
+# HELP rocket_http_requests_total Total number of HTTP requests
+# TYPE rocket_http_requests_total counter
+rocket_http_requests_total{endpoint="/hello/<name>?<caps>",method="GET",status="200"} 3
+rocket_http_requests_total{endpoint="/hello/<name>?<caps>",method="POST",status="200"} 1"#
+    );
+}