fix: OS signal

Close #79
https://stackoverflow.com/questions/77585473/rust-tokio-how-to-handle-more-signals-than-just-sigint-i-e-sigquit
https://docs.docker.com/engine/reference/commandline/stop/

src/main.rs

@@ -14,7 +14,7 @@ use axum::{
 };
 use forward::info::Layer;
 use http::header::ToStrError;
-use log::info;
+use log::{info, debug, error};
 use thiserror::Error;
 #[cfg(debug_assertions)]
 use tower_http::services::{ServeDir, ServeFile};
@@ -37,6 +37,7 @@ mod forward;
 mod media;
 mod metrics;
 mod path;
+mod signal;
 
 #[tokio::main]
 async fn main() {
@@ -91,10 +92,11 @@ async fn main() {
         .route("/metrics", get(metrics))
         .with_state(app_state);
     app = static_server(app);
-    axum::Server::bind(&addr)
-        .serve(app.into_make_service())
-        .await
-        .unwrap();
+    tokio::select!{
+        Err(e) = axum::Server::bind(&addr).serve(app.into_make_service()) => error!("Application error: {e}"),
+        msg = signal::wait_for_stop_signal() => debug!("Received signal: {}", msg),
+    }
+    info!("Server shutdown");
 }
 
 async fn metrics() -> String {

src/signal.rs

@@ -0,0 +1,43 @@
+/// References: https://stackoverflow.com/questions/77585473/rust-tokio-how-to-handle-more-signals-than-just-sigint-i-e-sigquit
+
+/// Waits for a signal that requests a graceful shutdown, like SIGTERM or SIGINT.
+#[cfg(unix)]
+async fn wait_for_signal_impl() -> String {
+    use tokio::signal::unix::{signal, SignalKind};
+
+    // Infos here:
+    // https://www.gnu.org/software/libc/manual/html_node/Termination-Signals.html
+    let mut signal_terminate = signal(SignalKind::terminate()).unwrap();
+    let mut signal_interrupt = signal(SignalKind::interrupt()).unwrap();
+
+    tokio::select! {
+        _ = signal_terminate.recv() => "SIGTERM".to_string(),
+        _ = signal_interrupt.recv() => "SIGINT".to_string(),
+    }
+}
+
+/// Waits for a signal that requests a graceful shutdown, Ctrl-C (SIGINT).
+#[cfg(windows)]
+async fn wait_for_signal_impl() -> String {
+    use tokio::signal::windows;
+
+    // Infos here:
+    // https://learn.microsoft.com/en-us/windows/console/handlerroutine
+    let mut signal_c = windows::ctrl_c().unwrap();
+    let mut signal_break = windows::ctrl_break().unwrap();
+    let mut signal_close = windows::ctrl_close().unwrap();
+    let mut signal_shutdown = windows::ctrl_shutdown().unwrap();
+
+    tokio::select! {
+        _ = signal_c.recv() => "CTRL_C".to_string(),
+        _ = signal_break.recv() => "CTRL_BREAK".to_string(),
+        _ = signal_close.recv() => "CTRL_CLOSE".to_string(),
+        _ = signal_shutdown.recv() => "CTRL_SHUTDOWN".to_string(),
+    }
+}
+
+/// Registers signal handlers and waits for a signal that
+/// indicates a shutdown request.
+pub(crate) async fn wait_for_stop_signal() -> String {
+    wait_for_signal_impl().await
+}