Makes max connection configurable

src/db.rs

@@ -7,11 +7,20 @@ use std::{env, time::Duration};
 
 pub const DEFAULT_MAX_CONNECTIONS: u32 = 2;
 
+pub fn max_connections() -> u32 {
+    if let Ok(txt) = env::var("MAX_CONNECTIONS") {
+        if let Ok(num) = txt.parse() {
+            return num;
+        }
+    }
+    DEFAULT_MAX_CONNECTIONS
+}
+
 pub fn from_env() -> Result<Pool<ConnectionManager<PgConnection>>> {
     let url = env::var("DATABASE_URL").context("Missing `DATABASE_URL` environment variable")?;
     let manager = ConnectionManager::<PgConnection>::new(url);
     let pool = Pool::builder()
-        .max_size(DEFAULT_MAX_CONNECTIONS)
+        .max_size(max_connections())
         .max_lifetime(Some(Duration::from_secs(300)))
         .idle_timeout(Some(Duration::from_secs(60)))
         .build(manager)

src/telegram.rs

@@ -90,7 +90,7 @@ async fn webhook(
 ) -> Result<()> {
     let url = Url::parse(format!("https://{host}/webhook").as_str())?;
     let opts = webhooks::Options::new((DEFAULT_HOST_IP, port).into(), url.clone())
-        .max_connections(db::DEFAULT_MAX_CONNECTIONS as u8);
+        .max_connections(db::max_connections() as u8);
     dispatcher
         .dispatch_with_listener(
             webhooks::axum(bot, opts).await?,