use std::net::TcpListener; use email_newsletter_api::{configuration::get_configuration, startup}; #[tokio::main] async fn main() -> Result<(), std::io::Error> { let configuration = get_configuration().expect("Failed to read configuration"); let port_number = configuration.application_port; let listener = TcpListener::bind(format!("127.0.0.1:{}", port_number)) .unwrap_or_else(|_| panic!("Can't bind to port {} at localhost", port_number)); // Move the error up the call stack // otherwise await for the HttpServer startup::run(listener)?.await }