Added basic prometheus metrics

Cargo.lock

@@ -8,6 +8,17 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "ahash"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcb51a0695d8f838b1ee009b3fbf66bda078cd64590202a864a8f3e8c4315c47"
+dependencies = [
+ "getrandom",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "ansi_term"
 version = "0.12.1"
@@ -28,6 +39,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "atomic-shim"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67cd4b51d303cf3501c301e8125df442128d3c6d7c69f71b27833d253de47e77"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -91,6 +111,12 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bumpalo"
+version = "3.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a45a46ab1f2412e53d3a0ade76ffad2025804294569aae387231a0cd6e0899"
+
 [[package]]
 name = "bytes"
 version = "1.1.0"
@@ -112,6 +138,30 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1145cf131a2c6ba0615079ab6a638f7e1973ac9c2634fcbeaaad6114246efe8c"
+dependencies = [
+ "autocfg",
+ "cfg-if",
+ "crossbeam-utils",
+ "lazy_static",
+ "memoffset",
+ "scopeguard",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bf124c720b7686e3c2663cf54062ab0f68a88af2fb6a030e87e30bf721fcb38"
+dependencies = [
+ "cfg-if",
+ "lazy_static",
+]
+
 [[package]]
 name = "filetime"
 version = "0.2.15"
@@ -239,6 +289,9 @@ name = "hashbrown"
 version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+dependencies = [
+ "ahash",
+]
 
 [[package]]
 name = "hermit-abi"
@@ -323,12 +376,36 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "instant"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
+dependencies = [
+ "cfg-if",
+]
+
+[[package]]
+name = "ipnet"
+version = "2.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35e70ee094dc02fd9c13fdad4940090f22dbd6ac7c9e7094a46cf0232a50bc7c"
+
 [[package]]
 name = "itoa"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
 
+[[package]]
+name = "js-sys"
+version = "0.3.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a38fc24e30fd564ce974c02bf1d337caddff65be6cc4735a1f7eab22a7440f04"
+dependencies = [
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -360,6 +437,15 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "mach"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b823e83b2affd8f40a9ee8c29dbc56404c1e34cd2710921f2801e2cf29527afa"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "matchers"
 version = "0.1.0"
@@ -387,6 +473,71 @@ version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 
+[[package]]
+name = "memoffset"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "metrics"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e52eb6380b6d2a10eb3434aec0885374490f5b82c8aaf5cd487a183c98be834"
+dependencies = [
+ "ahash",
+ "metrics-macros",
+]
+
+[[package]]
+name = "metrics-exporter-prometheus"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b93b470b04c005178058e18ac8bb2eb3fda562cf87af5ea05ba8d44190d458c"
+dependencies = [
+ "hyper",
+ "indexmap",
+ "ipnet",
+ "metrics",
+ "metrics-util",
+ "parking_lot 0.11.2",
+ "quanta",
+ "thiserror",
+ "tokio",
+ "tracing",
+]
+
+[[package]]
+name = "metrics-macros"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49e30813093f757be5cf21e50389a24dc7dbb22c49f23b7e8f51d69b508a5ffa"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "metrics-util"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "107a38013e91c04ddf31826b0d0dcc2e0d4ebedded8234cc0dc2b7bbd0c121e8"
+dependencies = [
+ "atomic-shim",
+ "crossbeam-epoch",
+ "crossbeam-utils",
+ "hashbrown",
+ "metrics",
+ "num_cpus",
+ "parking_lot 0.11.2",
+ "quanta",
+ "sketches-ddsketch",
+]
+
 [[package]]
 name = "mime"
 version = "0.3.16"
@@ -461,6 +612,17 @@ version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "87f3e037eac156d1775da914196f0f37741a274155e34a0b7e427c35d2a2ecb9"
 
+[[package]]
+name = "parking_lot"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d17b78036a60663b797adeaee46f5c9dfebb86948d1255007a1d6be0271ff99"
+dependencies = [
+ "instant",
+ "lock_api",
+ "parking_lot_core 0.8.5",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.0"
@@ -468,7 +630,21 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "87f5ec2493a61ac0506c0f4199f99070cbe83857b0337006a30f3e6719b8ef58"
 dependencies = [
  "lock_api",
- "parking_lot_core",
+ "parking_lot_core 0.9.2",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d76e8e1493bcac0d2766c42737f34458f1c8c50c0d23bcb24ea953affb273216"
+dependencies = [
+ "cfg-if",
+ "instant",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "winapi",
 ]
 
 [[package]]
@@ -531,6 +707,22 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "quanta"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20afe714292d5e879d8b12740aa223c6a88f118af41870e8b6196e39a02238a8"
+dependencies = [
+ "crossbeam-utils",
+ "libc",
+ "mach",
+ "once_cell",
+ "raw-cpuid",
+ "wasi 0.10.2+wasi-snapshot-preview1",
+ "web-sys",
+ "winapi",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.17"
@@ -540,6 +732,15 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "raw-cpuid"
+version = "10.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "738bc47119e3eeccc7e94c4a506901aea5e7b4944ecd0829cbebf4af04ceda12"
+dependencies = [
+ "bitflags",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.13"
@@ -634,12 +835,14 @@ dependencies = [
 
 [[package]]
 name = "site-backend"
-version = "0.1.2"
+version = "0.1.3"
 dependencies = [
  "axum",
  "flate2",
  "futures-util",
  "hyper",
+ "metrics",
+ "metrics-exporter-prometheus",
  "serde_json",
  "tar",
  "tokio",
@@ -650,6 +853,12 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "sketches-ddsketch"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76a77a8fd93886010f05e7ea0720e569d6d16c65329dbe3ec033bbbccccb017b"
+
 [[package]]
 name = "slab"
 version = "0.4.5"
@@ -700,6 +909,26 @@ dependencies = [
  "xattr",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "854babe52e4df1653706b98fcfc05843010039b406875930a70e4d9644e5c417"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.1.4"
@@ -721,7 +950,7 @@ dependencies = [
  "mio",
  "num_cpus",
  "once_cell",
- "parking_lot",
+ "parking_lot 0.12.0",
  "pin-project-lite",
  "signal-hook-registry",
  "socket2",
@@ -937,6 +1166,70 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25f1af7423d8588a3d840681122e72e6a24ddbcb3f0ec385cac0d12d24256c06"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b21c0df030f5a177f3cba22e9bc4322695ec43e7257d865302900290bcdedca"
+dependencies = [
+ "bumpalo",
+ "lazy_static",
+ "log",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f4203d69e40a52ee523b2529a773d5ffc1dc0071801c87b3d270b471b80ed01"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa8a30d46208db204854cadbb5d4baf5fcf8071ba5bf48190c3e59937962ebc"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d958d035c4438e28c70e4321a2911302f10135ce78a9c7834c0cab4123d06a2"
+
+[[package]]
+name = "web-sys"
+version = "0.3.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c060b319f29dd25724f09a2ba1418f142f539b2be99fbf4d2d5a8f7330afb8eb"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "site-backend"
-version = "0.1.2"
+version = "0.1.3"
 edition = "2021"
 publish = false
 
@@ -23,3 +23,5 @@ tokio-util = { version = "0.7.1", features = ["io"] }
 futures-util = "0.3.21"
 uuid = { version = "1.0.0-alpha.1", features = ["v4"] }
 serde_json = "1.0.79"
+metrics = "0.18.1"
+metrics-exporter-prometheus = "0.9.0"

src/main.rs

@@ -1,11 +1,18 @@
-use std::net::SocketAddr;
+use std::{future::ready, net::SocketAddr};
 
-use axum::{extract::Extension, http::StatusCode, routing::get_service, Router};
+use axum::{
+    extract::Extension,
+    http::StatusCode,
+    middleware,
+    routing::{get, get_service},
+    Router,
+};
 use tower_http::{auth::RequireAuthorizationLayer, services::ServeDir, trace::TraceLayer};
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
 mod api;
 mod matrix;
+mod metrics;
 
 const STATIC_DIR_NAME: &str = "static";
 
@@ -27,6 +34,8 @@ async fn main()
 
     std::fs::create_dir_all(&static_dir);
 
+    let recorder_handle = metrics::setup_metrics_recorder();
+
     let app = Router::new()
         // Handle Matrix .well-known files
         .nest("/", matrix::router())
@@ -35,6 +44,7 @@ async fn main()
             "/api",
             api::router().layer(RequireAuthorizationLayer::bearer(&api_key)),
         )
+        .route("/metrics", get(move || ready(recorder_handle.render())))
         // The fallback option is to serve the actual static files
         .fallback(get_service(ServeDir::new(static_dir)).handle_error(
             |error: std::io::Error| async move {
@@ -44,8 +54,9 @@ async fn main()
                 )
             },
         ))
-        .layer(TraceLayer::new_for_http())
-        .layer(Extension(data_dir));
+        .layer(middleware::from_fn(metrics::track_metrics))
+        .layer(Extension(data_dir))
+        .layer(TraceLayer::new_for_http());
 
     let addr = SocketAddr::from(([0, 0, 0, 0], 3000));
     tracing::debug!("listening on {}", addr);

src/metrics.rs

@@ -0,0 +1,48 @@
+use std::time::Instant;
+
+use axum::{extract::MatchedPath, http::Request, middleware::Next, response::IntoResponse};
+use metrics_exporter_prometheus::{Matcher, PrometheusBuilder, PrometheusHandle};
+
+pub fn setup_metrics_recorder() -> PrometheusHandle
+{
+    const EXPONENTIAL_SECONDS: &[f64] = &[
+        0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0,
+    ];
+
+    PrometheusBuilder::new()
+        .set_buckets_for_metric(
+            Matcher::Full("http_requests_duration_seconds".to_string()),
+            EXPONENTIAL_SECONDS,
+        )
+        .unwrap()
+        .install_recorder()
+        .unwrap()
+}
+
+// Taken from the examples section
+pub async fn track_metrics<B>(req: Request<B>, next: Next<B>) -> impl IntoResponse
+{
+    let start = Instant::now();
+    let path = if let Some(matched_path) = req.extensions().get::<MatchedPath>() {
+        matched_path.as_str().to_owned()
+    } else {
+        req.uri().path().to_owned()
+    };
+    let method = req.method().clone();
+
+    let response = next.run(req).await;
+
+    let latency = start.elapsed().as_secs_f64();
+    let status = response.status().as_u16().to_string();
+
+    let labels = [
+        ("method", method.to_string()),
+        ("path", path),
+        ("status", status),
+    ];
+
+    metrics::increment_counter!("http_requests_total", &labels);
+    metrics::histogram!("http_requests_duration_seconds", latency, &labels);
+
+    response
+}