Added monitoring, limited concurent connections (#245)

* reduced the default, and added environment override.

* Using parse is more stable and doesn't fail CI this time :P

* Added support for monitoring
This support is currently basic, but it can be improved later down the road.

* Forgot scheduler file

* Added health check

* Cargo fix

* Update cargo.lock to avoid action fails.

Co-authored-by: Geometrically <18202329+Geometrically@users.noreply.github.com>

src/routes/health.rs

@@ -0,0 +1,31 @@
+use actix_web::{get, HttpResponse};
+use serde_json::json;
+use crate::health::status::test_database;
+use actix_web::web::Data;
+use sqlx::PgPool;
+use crate::health::SEARCH_READY;
+use std::sync::atomic::Ordering;
+
+#[get("/health")]
+pub async fn health_get(client: Data<PgPool>) -> HttpResponse {
+    // Check database connection:
+    let result = test_database(client).await;
+    if result.is_err() {
+        let data = json!({
+            "ready": false,
+            "reason": "Database connection error"
+        });
+        return HttpResponse::InternalServerError().json(data)
+    }
+    if !SEARCH_READY.load(Ordering::Acquire) {
+        let data = json!({
+            "ready": false,
+            "reason": "Indexing is not finished"
+        });
+        return HttpResponse::InternalServerError().json(data)
+    }
+    HttpResponse::Ok().json(json!({
+        "ready": true,
+        "reason": "Everything is OK"
+    }))
+}

src/routes/mod.rs

@@ -18,11 +18,13 @@ mod users;
 mod version_creation;
 mod version_file;
 mod versions;
+mod health;
 
 pub use auth::config as auth_config;
 pub use tags::config as tags_config;
 
 pub use self::index::index_get;
+pub use self::health::health_get;
 pub use self::not_found::not_found;
 use crate::file_hosting::FileHostingError;