request latency and response metrics

src/main.rs

 use blog::{Blog, RenderedBlog};
 use config::Config;
-use metrics::{BUILD_BLOG_FROM_ASSETS, HTTP_COUNTER, INVALID_EXPIRES_HEADER_VALUE};
+use metrics::{
+    BUILD_BLOG_FROM_ASSETS, HTTP_COUNTER, INVALID_EXPIRES_HEADER_VALUE, REQUEST_LATENCY,
+    RESPONSE_COUNTER,
+};
 use path::UrlPath;
 use std::sync::Arc;
 use tokio::sync::RwLock;
@@ -33,6 +36,8 @@ async fn handle_request(
     req: FullPath,
     blog: Arc<RwLock<RenderedBlog>>,
 ) -> Result<impl warp::Reply, warp::Rejection> {
+    let timer = REQUEST_LATENCY.start_timer();
+
     let path = UrlPath::new(req.as_str());
     HTTP_COUNTER.with_label_values(&[&path.to_string()]).inc();
 
@@ -55,6 +60,12 @@ async fn handle_request(
     }
     *reply.status_mut() = status;
 
+    RESPONSE_COUNTER
+        .with_label_values(&[&status.as_u16().to_string()])
+        .inc();
+
+    timer.observe_duration();
+
     Ok(reply)
 }
 

src/metrics.rs

@@ -23,6 +23,10 @@ lazy_static! {
         vec![0.5, 1.0, 2.5, 5.0, 10.0, 25.0, 50.0, 100.0]
     )
     .unwrap();
+    pub static ref REQUEST_LATENCY: Histogram =
+        register_histogram!("org_request_latency_seconds", "Request latency").unwrap();
+    pub static ref RESPONSE_COUNTER: CounterVec =
+        register_counter_vec!("org_response_total", "HTTP response codes", &["code"]).unwrap();
 }
 
 #[derive(Deserialize)]