tests: check than all metrics name start with 'garage_' prefix

src/garage/tests/common/garage.rs

@@ -194,6 +194,15 @@ api_bind_addr = "127.0.0.1:{admin_port}"
 			.expect("Could not build garage endpoint URI")
 	}
 
+	pub fn admin_uri(&self, path: &str) -> http::Uri {
+		format!(
+			"http://127.0.0.1:{admin_port}/{path}",
+			admin_port = self.admin_port,
+		)
+		.parse()
+		.expect("Could not build garage endpoint URI")
+	}
+
 	pub fn key(&self, maybe_name: Option<&str>) -> Key {
 		let mut key = Key::default();
 

src/garage/tests/lib.rs

@@ -4,6 +4,9 @@ mod common;
 mod admin;
 mod bucket;
 
+#[cfg(feature = "metrics")]
+mod metrics;
+
 mod s3;
 
 #[cfg(feature = "k2v")]

src/garage/tests/metrics.rs

@@ -0,0 +1,49 @@
+use bytes::Bytes;
+use http::{Request, StatusCode};
+use http_body_util::{BodyExt, Full};
+
+use crate::common;
+
+#[tokio::test]
+async fn check_metrics_name() {
+	let ctx = common::context();
+
+	let req_url = ctx.garage.admin_uri("metrics");
+	let client = ctx.custom_request.client();
+	let get_metrics_req = Request::builder()
+		.method("GET")
+		.uri(req_url)
+		.body(Full::new(Bytes::new()))
+		.unwrap();
+
+	let response = client
+		.request(get_metrics_req)
+		.await
+		.expect("failed to build 'get metrics' request");
+
+	assert_eq!(response.status(), StatusCode::OK);
+	let body = BodyExt::collect(response.into_body())
+		.await
+		.expect("failed to collect bytes from body stream")
+		.to_bytes();
+	let body = String::from_utf8_lossy(&body);
+
+	//dbg!(&body);
+	let invalid_metrics_name = body
+		.lines()
+		.filter(isnot_comment_line) // skip the comment lines
+		.filter(hasnt_prefix_garage)
+		.collect::<Vec<_>>();
+
+	if !invalid_metrics_name.is_empty() {
+		panic!("metrics name should all start with 'garage_' prefix.\nDoc: https://prometheus.io/docs/practices/naming/#metric-names\n\nInvalid:\n{:#?}", invalid_metrics_name);
+	}
+}
+
+fn isnot_comment_line(line: &&str) -> bool {
+	!line.starts_with("#")
+}
+
+fn hasnt_prefix_garage(line: &&str) -> bool {
+	!line.starts_with("garage_")
+}