move hyper prometheus example into something runnable (#562)

open-telemetry · Jun 2, 2021 · fb576b0 · fb576b0
1 parent 1235682
commit fb576b0
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Showing 3 changed files with 42 additions and 15 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -24,6 +24,7 @@ members = [
     "examples/external-otlp-tonic-tokio",
     "examples/grpc",
     "examples/http",
+    "examples/hyper-prometheus",
     "examples/tracing-grpc",
     "examples/zipkin",
     "examples/multiple-span-processors"

diff --git a/examples/hyper-prometheus/Cargo.toml b/examples/hyper-prometheus/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "hyper-prometheus"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio"] }
+opentelemetry-prometheus = { path = "../../opentelemetry-prometheus" }
+prometheus = "0.12"
+lazy_static = "1.4"
+hyper = { version = "0.14", features = ["full"] }
+tokio = { version = "1", features = ["full"] }
diff --git a/opentelemetry-prometheus/examples/hyper.rs → examples/hyper-prometheus/src/main.rs b/opentelemetry-prometheus/examples/hyper.rs → examples/hyper-prometheus/src/main.rs
@@ -4,7 +4,7 @@ extern crate lazy_static;
 use hyper::{
     header::CONTENT_TYPE,
     service::{make_service_fn, service_fn},
-    Body, Request, Response, Server,
+    Body, Method, Request, Response, Server,
 };
 use opentelemetry::{
     global,
@@ -22,29 +22,41 @@ lazy_static! {
 }
 
 async fn serve_req(
-    _req: Request<Body>,
+    req: Request<Body>,
     state: Arc<AppState>,
 ) -> Result<Response<Body>, hyper::Error> {
+    println!("Receiving request at path {}", req.uri());
     let request_start = SystemTime::now();
 
-    let mut buffer = vec![];
-    let encoder = TextEncoder::new();
-    let metric_families = state.exporter.registry().gather();
-    encoder.encode(&metric_families, &mut buffer).unwrap();
-
     state.http_counter.add(1);
-    state.http_body_gauge.record(buffer.len() as u64);
 
-    let response = Response::builder()
-        .status(200)
-        .header(CONTENT_TYPE, encoder.format_type())
-        .body(Body::from(buffer))
-        .unwrap();
+    let response = match (req.method(), req.uri().path()) {
+        (&Method::GET, "/metrics") => {
+            let mut buffer = vec![];
+            let encoder = TextEncoder::new();
+            let metric_families = state.exporter.registry().gather();
+            encoder.encode(&metric_families, &mut buffer).unwrap();
+            state.http_body_gauge.record(buffer.len() as u64);
+
+            Response::builder()
+                .status(200)
+                .header(CONTENT_TYPE, encoder.format_type())
+                .body(Body::from(buffer))
+                .unwrap()
+        }
+        (&Method::GET, "/") => Response::builder()
+            .status(200)
+            .body(Body::from("Hello World"))
+            .unwrap(),
+        _ => Response::builder()
+            .status(404)
+            .body(Body::from("Missing Page"))
+            .unwrap(),
+    };
 
     state
         .http_req_histogram
         .record(request_start.elapsed().map_or(0.0, |d| d.as_secs_f64()));
-
     Ok(response)
 }
 
@@ -69,7 +81,7 @@ pub async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
             .bind(HANDLER_ALL.as_ref()),
         http_body_gauge: meter
             .u64_value_recorder("example.http_response_size_bytes")
-            .with_description("The HTTP response sizes in bytes.")
+            .with_description("The metrics HTTP response sizes in bytes.")
             .init()
             .bind(HANDLER_ALL.as_ref()),
         http_req_histogram: meter