From 9c5d3ef58e985621e50385450170a25f96e5e497 Mon Sep 17 00:00:00 2001
From: Adrian Hedqvist <adrian@tollyx.net>
Date: Sun, 26 Mar 2023 00:30:21 +0100
Subject: [PATCH] fix metrics stuff

---
 Dockerfile            |  2 +-
 src/handlers/mod.rs   |  4 ++--
 src/handlers/posts.rs |  4 ++--
 src/main.rs           | 17 ++++++++++++++++-
 src/post.rs           |  2 +-
 5 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 654e314..5d66c30 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -34,7 +34,7 @@ RUN adduser \
 WORKDIR /app
 
 COPY --from=planner /app/recipe.json .
-RUN cargo chef cook --release --recipe-path recipe.json
+RUN cargo chef cook --target x86_64-unknown-linux-musl --release --recipe-path recipe.json
 
 COPY . .
 
diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index a5f2d57..eeadb95 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -14,7 +14,7 @@ pub mod posts;
 
 lazy_static! {
     pub static ref HIT_COUNTER: IntCounterVec =
-        prometheus::register_int_counter_vec!(opts!("hits", "page hits"), &["page"]).unwrap();
+        prometheus::register_int_counter_vec!(opts!("page_hits", "Number of hits to various pages"), &["page"]).unwrap();
 }
 
 #[instrument(skip(state))]
@@ -26,7 +26,7 @@ pub async fn index(
         error!("Failed rendering index: {}", e);
         WebsiteError::NotFound
     })?;
-    HIT_COUNTER.with_label_values(&["/"]);
+    HIT_COUNTER.with_label_values(&["/"]).inc();
     Ok(Html(res.into()))
 }
 
diff --git a/src/handlers/posts.rs b/src/handlers/posts.rs
index 0efaf78..b47648c 100644
--- a/src/handlers/posts.rs
+++ b/src/handlers/posts.rs
@@ -28,7 +28,7 @@ pub async fn view(
 
     let res = render_post(&state.tera, post).await?;
 
-    HIT_COUNTER.with_label_values(&[&format!("/posts/{}/", slug)]);
+    HIT_COUNTER.with_label_values(&[&format!("/posts/{}/", slug)]).inc();
     Ok(Html(res))
 }
 
@@ -61,6 +61,6 @@ pub async fn index(Extension(state): Extension<Arc<State>>) -> Result<Html<Strin
         }
     };
 
-    HIT_COUNTER.with_label_values(&["/posts/"]);
+    HIT_COUNTER.with_label_values(&["/posts/"]).inc();
     Ok(Html(res))
 }
diff --git a/src/main.rs b/src/main.rs
index 32e1e02..1a87c3c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,10 @@
 use std::{collections::HashMap, sync::Arc};
 
-use axum::{routing::get, Extension, Router};
+use axum::{routing::get, Extension, Router, response::Response, body};
 use color_eyre::eyre::Result;
+use hyper::header::CONTENT_TYPE;
 use post::Post;
+use prometheus::{TextEncoder, Encoder};
 use tera::Tera;
 use tower_http::{compression::CompressionLayer, trace::TraceLayer};
 use tracing::{instrument, log::*};
@@ -49,6 +51,7 @@ pub async fn init_app() -> Result<Router> {
         .nest("/posts", handlers::posts::router())
         .nest_service("/static", tower_http::services::ServeDir::new("./static"))
         .route("/.healthcheck", get(healthcheck))
+        .route("/metrics", get(metrics))
         .layer(middleware);
 
     Ok(app)
@@ -58,6 +61,18 @@ async fn healthcheck() -> &'static str {
     "OK"
 }
 
+async fn metrics() -> Response {
+    let encoder = TextEncoder::new();
+    let metric_families = prometheus::gather();
+    let mut buffer = vec![];
+    encoder.encode(&metric_families, &mut buffer).unwrap();
+    Response::builder()
+        .status(200)
+        .header(CONTENT_TYPE, encoder.format_type())
+        .body(body::boxed(body::Full::from(buffer)))
+        .unwrap()
+}
+
 #[derive(Debug)]
 pub enum WebsiteError {
     NotFound,
diff --git a/src/post.rs b/src/post.rs
index f4bf996..83ce45b 100644
--- a/src/post.rs
+++ b/src/post.rs
@@ -138,7 +138,7 @@ mod tests {
     use tera::Tera;
 
     #[tokio::test]
-    async fn render_all() {
+    async fn render_all_posts() {
         let tera = Tera::new("templates/**/*").unwrap();
         let posts = super::load_all().await.unwrap();