allow using other signals for graceful shutdown

server-cli/src/main.rs

@@ -55,10 +55,7 @@ fn main() -> io::Result<()> {
     // noninteractive implies basic
     let basic = basic || noninteractive;
 
-    let sigusr1_signal = Arc::new(AtomicBool::new(false));
-
-    #[cfg(any(target_os = "linux", target_os = "macos"))]
-    let _ = signal_hook::flag::register(signal_hook::consts::SIGUSR1, Arc::clone(&sigusr1_signal));
+    let shutdown_signal = Arc::new(AtomicBool::new(false));
 
     let (_guards, _guards2) = if basic {
         (Vec::new(), common_frontend::init_stdout(None))
@@ -69,6 +66,16 @@ fn main() -> io::Result<()> {
     // Load settings
     let settings = settings::Settings::load();
 
+    #[cfg(any(target_os = "linux", target_os = "macos"))]
+    {
+        for signal in &settings.shutdown_signals {
+            let _ = signal_hook::flag::register(
+                *signal as core::ffi::c_int,
+                Arc::clone(&shutdown_signal),
+            );
+        }
+    }
+
     // Determine folder to save server data in
     let server_data_dir = {
         let mut path = common_base::userdata_dir_workspace!();
@@ -234,7 +241,7 @@ fn main() -> io::Result<()> {
         "Server is ready to accept connections."
     );
 
-    let mut shutdown_coordinator = ShutdownCoordinator::new(Arc::clone(&sigusr1_signal));
+    let mut shutdown_coordinator = ShutdownCoordinator::new(Arc::clone(&shutdown_signal));
 
     // Set up an fps clock
     let mut clock = Clock::new(Duration::from_secs_f64(1.0 / TPS as f64));

server-cli/src/settings.rs

@@ -6,6 +6,15 @@ use std::{
 };
 use tracing::warn;
 
+#[derive(Clone, Copy, Debug, Serialize, Deserialize)]
+#[repr(i32)]
+#[allow(clippy::upper_case_acronyms)]
+pub enum ShutdownSignal {
+    SIGUSR1 = signal_hook::consts::SIGUSR1,
+    SIGUSR2 = signal_hook::consts::SIGUSR2,
+    SIGTERM = signal_hook::consts::SIGTERM,
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize)]
 #[serde(default)]
 pub struct Settings {
@@ -15,6 +24,7 @@ pub struct Settings {
     /// SECRET API HEADER used to access the chat api, if disabled the API is
     /// unreachable
     pub web_chat_secret: Option<String>,
+    pub shutdown_signals: Vec<ShutdownSignal>,
 }
 
 impl Default for Settings {
@@ -24,6 +34,7 @@ impl Default for Settings {
             update_shutdown_message: "The server is restarting for an update".to_owned(),
             web_address: SocketAddr::from((Ipv4Addr::LOCALHOST, 14005)),
             web_chat_secret: None,
+            shutdown_signals: vec![ShutdownSignal::SIGUSR1],
         }
     }
 }

server-cli/src/shutdown_coordinator.rs

@@ -13,8 +13,8 @@ use std::{
 use tracing::{error, info};
 
 /// Coordinates the shutdown procedure for the server, which can be initiated by
-/// either the TUI console interface or by sending the server the SIGUSR1 signal
-/// which indicates the server is restarting due to an update.
+/// either the TUI console interface or by sending the server the SIGUSR1 (or
+/// others) signal which indicates the server is restarting due to an update.
 pub(crate) struct ShutdownCoordinator {
     /// The instant that the last shutdown message was sent, used for
     /// calculating when to send the next shutdown message
@@ -28,19 +28,19 @@ pub(crate) struct ShutdownCoordinator {
     /// The message to use for the shutdown warning message that is sent to all
     /// connected players
     shutdown_message: String,
-    /// Provided by `signal_hook` to allow observation of the SIGUSR1 signal
-    sigusr1_signal: Arc<AtomicBool>,
+    /// Provided by `signal_hook` to allow observation of a shutdown signal
+    shutdown_signal: Arc<AtomicBool>,
 }
 
 impl ShutdownCoordinator {
-    pub fn new(sigusr1_signal: Arc<AtomicBool>) -> Self {
+    pub fn new(shutdown_signal: Arc<AtomicBool>) -> Self {
         Self {
             last_shutdown_msg: Instant::now(),
             msg_interval: Duration::from_secs(30),
             shutdown_initiated_at: None,
             shutdown_grace_period: Duration::from_secs(0),
             shutdown_message: String::new(),
-            sigusr1_signal,
+            shutdown_signal,
         }
     }
 
@@ -81,8 +81,8 @@ impl ShutdownCoordinator {
     /// returns `true` which triggers the loop in `main.rs` to break and
     /// exit the server process.
     pub fn check(&mut self, server: &mut Server, settings: &Settings) -> bool {
-        // Check whether SIGUSR1 has been set
-        self.check_sigusr1_signal(server, settings);
+        // Check whether shutdown has been set
+        self.check_shutdown_signal(server, settings);
 
         // If a shutdown is in progress, check whether it's time to send another warning
         // message or shut down if the grace period has expired.
@@ -109,14 +109,14 @@ impl ShutdownCoordinator {
         false
     }
 
-    /// Checks whether the SIGUSR1 signal has been set, which is used to trigger
-    /// a graceful shutdown for an update. [Watchtower](https://containrrr.dev/watchtower/) is configured on the main
+    /// Checks whether a shutdown (SIGUSR1 by default) signal has been set,
+    /// which is used to trigger a graceful shutdown for an update. [Watchtower](https://containrrr.dev/watchtower/) is configured on the main
     /// Veloren server to send SIGUSR1 instead of SIGTERM which allows us to
     /// react specifically to shutdowns that are for an update.
     /// NOTE: SIGUSR1 is not supported on Windows
-    fn check_sigusr1_signal(&mut self, server: &mut Server, settings: &Settings) {
-        if self.sigusr1_signal.load(Ordering::Relaxed) && self.shutdown_initiated_at.is_none() {
-            info!("Received SIGUSR1 signal, initiating graceful shutdown");
+    fn check_shutdown_signal(&mut self, server: &mut Server, settings: &Settings) {
+        if self.shutdown_signal.load(Ordering::Relaxed) && self.shutdown_initiated_at.is_none() {
+            info!("Received shutdown signal, initiating graceful shutdown");
             let grace_period =
                 Duration::from_secs(u64::from(settings.update_shutdown_grace_period_secs));
             let shutdown_message = settings.update_shutdown_message.to_owned();
@@ -124,7 +124,7 @@ impl ShutdownCoordinator {
 
             // Reset the SIGUSR1 signal indicator in case shutdown is aborted and we need to
             // trigger shutdown again
-            self.sigusr1_signal.store(false, Ordering::Relaxed);
+            self.shutdown_signal.store(false, Ordering::Relaxed);
         }
     }