Working on rust backend

backend/src/db.rs

@@ -0,0 +1,30 @@
+use crate::error_handler::CustomError;
+use diesel::pg::PgConnection;
+use diesel::r2d2::ConnectionManager;
+use lazy_static::lazy_static;
+use r2d2;
+use std::env;
+
+type Pool = r2d2::Pool<ConnectionManager<PgConnection>>;
+pub type DbConnection = r2d2::PooledConnection<ConnectionManager<PgConnection>>;
+
+embed_migrations!();
+
+lazy_static! {
+    static ref POOL: Pool = {
+        let db_url = env::var("DATABASE_URL").expect("Database url not set");
+        let manager = ConnectionManager::<PgConnection>::new(db_url);
+        Pool::new(manager).expect("Failed to create db pool")
+    };
+}
+
+pub fn init() {
+    lazy_static::initialize(&POOL);
+    let conn = connection().expect("Failed to get db connection");
+    embedded_migrations::run(&conn).unwrap();
+}
+
+pub fn connection() -> Result<DbConnection, CustomError> {
+    POOL.get()
+        .map_err(|e| CustomError::new(500, format!("Failed getting db connection: {}", e)))
+}