Completed the health check with a db connection test

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

src/main.rs

@@ -7,26 +7,36 @@ mod model;
 mod route;
 mod lib;
 
-use actix_web::{App, HttpServer, Responder, web};
+use actix_web::{App, HttpServer, Responder, web, HttpResponse};
 use std::env;
+use diesel::{PgConnection, Connection};
 
 
 async fn health() -> impl Responder {
-    "Healthy"
+    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
+    match PgConnection::establish(&database_url) {
+        Ok(_value) => HttpResponse::Ok().body("Healthy"),
+        Err(_e) => {
+            eprintln!("Could not connect to PostgreSQL.");
+            eprintln!("Error connecting to {}", database_url);
+            HttpResponse::InternalServerError().body("Cannot connect to database.")
+        }
+    }
 }
 
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
+    let server_string = format!("{}:{}",
+                                env::var("HOST_IP").unwrap_or("0.0.0.0".to_string()),
+                                env::var("HOST_PORT").unwrap_or("8080".to_string()));
+    println!("Server will be listening: {}", server_string);
     HttpServer::new(|| {
         App::new().service(web::scope("/v1")
                 .configure(route::init_routes)
         )
             .route("/health", web::get().to(health))
     })
-        .bind(format!("{}:{}",
+        .bind(server_string)?
-                      env::var("HOST_IP").unwrap_or("0.0.0.0".to_string()),
-                      env::var("HOST_PORT").unwrap_or("8080".to_string())
-        ))?
         .run()
         .await
 }