add active players and rooms gauges

src/core/player.rs

@@ -12,6 +12,7 @@ use std::{
     sync::{Arc, RwLock},
 };
 
+use prometheus::{IntGauge, Registry as MetricsRegistry};
 use tokio::{
     sync::mpsc::{channel, Receiver, Sender},
     task::JoinHandle,
@@ -19,6 +20,7 @@ use tokio::{
 
 use crate::{
     core::room::{RoomId, RoomRegistry},
+    prelude::*,
     util::table::AnonTable,
 };
 
@@ -96,13 +98,20 @@ enum PlayerCommand {
 #[derive(Clone)]
 pub struct PlayerRegistry(Arc<RwLock<PlayerRegistryInner>>);
 impl PlayerRegistry {
-    pub fn empty(room_registry: RoomRegistry) -> PlayerRegistry {
+    pub fn empty(
+        room_registry: RoomRegistry,
+        metrics: &mut MetricsRegistry,
+    ) -> Result<PlayerRegistry> {
+        let metric_active_players =
+            IntGauge::new("chat_players_active", "Number of alive player actors")?;
+        metrics.register(Box::new(metric_active_players.clone()))?;
         let inner = PlayerRegistryInner {
             next_id: PlayerId(0),
             room_registry,
             players: HashMap::new(),
+            metric_active_players,
         };
-        PlayerRegistry(Arc::new(RwLock::new(inner)))
+        Ok(PlayerRegistry(Arc::new(RwLock::new(inner))))
     }
 
     pub async fn create_player(&mut self) -> (PlayerId, PlayerHandle) {
@@ -114,6 +123,7 @@ impl PlayerRegistry {
         inner.next_id.0 += 1;
         let (handle, fiber) = player.launch(id, inner.room_registry.clone());
         inner.players.insert(id, (handle.clone(), fiber));
+        inner.metric_active_players.inc();
         (id, handle)
     }
 }
@@ -123,6 +133,7 @@ struct PlayerRegistryInner {
     next_id: PlayerId,
     room_registry: RoomRegistry,
     players: HashMap<PlayerId, (PlayerHandle, JoinHandle<Player>)>,
+    metric_active_players: IntGauge,
 }
 
 /// Player actor inner state representation.

src/core/room.rs

@@ -5,6 +5,7 @@ use std::{
     sync::{Arc, RwLock},
 };
 
+use prometheus::{IntGauge, Registry as MetricRegistry};
 use tokio::sync::mpsc::{channel, Sender};
 
 use crate::{
@@ -20,12 +21,16 @@ pub struct RoomId(pub u64);
 #[derive(Clone)]
 pub struct RoomRegistry(Arc<RwLock<RoomRegistryInner>>);
 impl RoomRegistry {
-    pub fn empty() -> RoomRegistry {
+    pub fn empty(metrics: &mut MetricRegistry) -> Result<RoomRegistry> {
+        let metric_active_rooms =
+            IntGauge::new("chat_rooms_active", "Number of alive room actors")?;
+        metrics.register(Box::new(metric_active_rooms.clone()))?;
         let inner = RoomRegistryInner {
             next_room_id: RoomId(0),
             rooms: HashMap::new(),
+            metric_active_rooms,
         };
-        RoomRegistry(Arc::new(RwLock::new(inner)))
+        Ok(RoomRegistry(Arc::new(RwLock::new(inner))))
     }
 
     pub fn create_room(&mut self) -> (RoomId, RoomHandle) {
@@ -50,6 +55,7 @@ impl RoomRegistry {
 struct RoomRegistryInner {
     next_room_id: RoomId,
     rooms: HashMap<RoomId, (RoomHandle, JoinHandle<Room>)>,
+    metric_active_rooms: IntGauge,
 }
 
 #[derive(Clone)]

src/main.rs

@@ -39,9 +39,9 @@ async fn main() -> Result<()> {
         telemetry: telemetry_config,
         irc: irc_config,
     } = config;
-    let metrics = MetricsRegistry::new();
-    let rooms = RoomRegistry::empty();
-    let players = PlayerRegistry::empty(rooms.clone());
+    let mut metrics = MetricsRegistry::new();
+    let rooms = RoomRegistry::empty(&mut metrics)?;
+    let players = PlayerRegistry::empty(rooms.clone(), &mut metrics)?;
     let telemetry_terminator = util::telemetry::launch(telemetry_config, metrics.clone()).await?;
     let irc = projections::irc::launch(irc_config, players, metrics.clone()).await?;
     tracing::info!("Started");