Serve metrics via :31755

Cargo.lock

@@ -139,6 +139,55 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "axum"
+version = "0.6.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b829e4e32b91e643de6eafe82b1d90675f5874230191a4ffbc1b336dec4d6bf"
+dependencies = [
+ "async-trait",
+ "axum-core",
+ "bitflags 1.3.2",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "hyper",
+ "itoa",
+ "matchit",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "rustversion",
+ "serde",
+ "serde_json",
+ "serde_path_to_error",
+ "serde_urlencoded",
+ "sync_wrapper",
+ "tokio",
+ "tower",
+ "tower-layer",
+ "tower-service",
+]
+
+[[package]]
+name = "axum-core"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "759fa577a247914fd3f7f76d62972792636412fbfd634cd452f6a385a74d2d2c"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "mime",
+ "rustversion",
+ "tower-layer",
+ "tower-service",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.68"
@@ -1080,6 +1129,12 @@ dependencies = [
  "regex-automata 0.1.10",
 ]
 
+[[package]]
+name = "matchit"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
+
 [[package]]
 name = "memchr"
 version = "2.5.0"
@@ -1967,6 +2022,16 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_path_to_error"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4beec8bce849d58d06238cb50db2e1c417cfeafa4c63f692b15c82b7c80f8335"
+dependencies = [
+ "itoa",
+ "serde",
+]
+
 [[package]]
 name = "serde_repr"
 version = "0.1.14"
@@ -2152,6 +2217,7 @@ dependencies = [
 name = "soundfx-rs"
 version = "1.5.11"
 dependencies = [
+ "axum",
  "dashmap",
  "dotenv",
  "env_logger",
@@ -2359,6 +2425,12 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
+
 [[package]]
 name = "tempfile"
 version = "3.6.0"
@@ -2551,6 +2623,28 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tokio",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c20c8dbed6283a09604c3e69b4b7eeb54e298b8a600d4d5ecb5ad39de609f1d0"
+
 [[package]]
 name = "tower-service"
 version = "0.3.2"

Cargo.toml

@@ -21,6 +21,10 @@ dashmap = "5.3"
 serde = "1.0"
 dotenv = "0.15.0"
 prometheus = { version = "0.13.3", optional = true }
+axum = { version = "0.6.20", optional = true }
+
+[features]
+metrics = ["dep:prometheus", "dep:axum"]
 
 [patch."https://github.com/serenity-rs/serenity"]
 serenity = { version = "0.11.6" }

src/cmds/play.rs

@@ -5,7 +5,7 @@ use poise::serenity_prelude::{
     ReactionType,
 };
 
-#[cfg(feature = "prometheus")]
+#[cfg(feature = "metrics")]
 use crate::metrics::PLAY_COUNTER;
 use crate::{
     cmds::autocomplete_sound,
@@ -29,7 +29,7 @@ pub async fn play(
 
     let guild = ctx.guild().unwrap();
 
-    #[cfg(feature = "prometheus")]
+    #[cfg(feature = "metrics")]
     PLAY_COUNTER.inc();
 
     ctx.say(

src/main.rs

@@ -5,7 +5,7 @@ mod cmds;
 mod consts;
 mod error;
 mod event_handlers;
-#[cfg(feature = "prometheus")]
+#[cfg(feature = "metrics")]
 mod metrics;
 mod models;
 mod utils;
@@ -144,6 +144,12 @@ async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
 
     sqlx::migrate!().run(&database).await?;
 
+    #[cfg(feature = "metrics")]
+    {
+        metrics::init_metrics();
+        tokio::spawn(async { metrics::serve().await });
+    }
+
     poise::Framework::builder()
         .token(discord_token)
         .setup(move |ctx, _bot, framework| {

src/metrics.rs

@@ -1,7 +1,40 @@
+use std::net::SocketAddr;
+
+use axum::{routing::get, Router};
 use lazy_static;
-use prometheus::{register_int_counter, IntCounter};
+use log::warn;
+use prometheus::{register_int_counter, IntCounter, Registry};
 
 lazy_static! {
+    static ref REGISTRY: Registry = Registry::new();
     pub static ref PLAY_COUNTER: IntCounter =
         register_int_counter!("play", "Number of calls to /play").unwrap();
 }
+
+pub fn init_metrics() {
+    REGISTRY.register(Box::new(PLAY_COUNTER.clone())).unwrap();
+}
+
+pub async fn serve() {
+    let app = Router::new().route("/", get(metrics));
+    let addr = SocketAddr::from(([127, 0, 0, 1], 31755));
+
+    axum::Server::bind(&addr)
+        .serve(app.into_make_service())
+        .await
+        .unwrap();
+}
+
+async fn metrics() -> String {
+    let encoder = prometheus::TextEncoder::new();
+    let res_custom = encoder.encode_to_string(&REGISTRY.gather());
+
+    match res_custom {
+        Ok(s) => s,
+        Err(e) => {
+            warn!("Error encoding metrics: {:?}", e);
+
+            String::new()
+        }
+    }
+}