add healthcheck endpoint and startup check

packages/backend/src/api.rs

@@ -1,12 +1,14 @@
 use actix_web::web;
 
+use crate::health;
 use crate::note;
 use crate::status;
 
 pub fn init(cfg: &mut web::ServiceConfig) {
     cfg.service(
         web::scope("/api")
             .service(note::init())
-            .service(status::init()),
+            .service(status::init())
+            .service(health::init()),
     );
 }

packages/backend/src/health/mod.rs

@@ -0,0 +1,3 @@
+mod routes;
+
+pub use routes::*;

packages/backend/src/health/routes.rs

@@ -0,0 +1,16 @@
+use actix_web::{get, web, HttpResponse, Responder, Scope};
+
+use crate::store;
+
+#[get("/")]
+async fn get_live() -> impl Responder {
+    if store::can_reach_redis() {
+        return HttpResponse::Ok();
+    } else {
+        return HttpResponse::ServiceUnavailable();
+    }
+}
+
+pub fn init() -> Scope {
+    web::scope("/live").service(get_live)
+}

packages/backend/src/main.rs

@@ -1,15 +1,18 @@
 use actix_web::{
     middleware::{self, Logger},
-    web, App, HttpServer,
+    web::{self},
+    App, HttpServer,
 };
 use dotenv::dotenv;
+use log::error;
 
 #[macro_use]
 extern crate lazy_static;
 
 mod api;
 mod client;
 mod config;
+mod health;
 mod note;
 mod size;
 mod status;
@@ -20,6 +23,11 @@ async fn main() -> std::io::Result<()> {
     dotenv().ok();
     env_logger::init_from_env(env_logger::Env::new().default_filter_or(config::VERBOSITY.as_str()));
 
+    if !store::can_reach_redis() {
+        error!("cannot reach redis");
+        panic!("canont reach redis");
+    }
+
     return HttpServer::new(|| {
         App::new()
             .wrap(Logger::new("\"%r\" %s %b %T"))

packages/backend/src/store.rs

@@ -19,6 +19,14 @@ fn get_connection() -> Result<redis::Connection, &'static str> {
         .map_err(|_| "Unable to connect to redis")
 }
 
+pub fn can_reach_redis() -> bool {
+    let conn = get_connection();
+    return match conn {
+        Ok(_) => true,
+        Err(_) => false,
+    };
+}
+
 pub fn set(id: &String, note: &Note) -> Result<(), &'static str> {
     let serialized = serde_json::to_string(&note.clone()).unwrap();
     let mut conn = get_connection()?;