Serve metrics via :31755

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()
+        }
+    }
+}