support reloading config via SIGUSR1

Signed-off-by: Jason Volk <jason@zemos.net>

conduwuit-example.toml

@@ -1524,6 +1524,11 @@
 #
 #listening = true
 
+# Enables configuration reload when the server receives SIGUSR1 on
+# supporting platforms.
+#
+#config_reload_signal = true
+
 [global.tls]
 
 # Path to a valid TLS certificate file.

src/admin/server/commands.rs

@@ -1,6 +1,6 @@
 use std::{fmt::Write, path::PathBuf, sync::Arc};
 
-use conduwuit::{info, utils::time, warn, Config, Err, Result};
+use conduwuit::{info, utils::time, warn, Err, Result};
 use ruma::events::room::message::RoomMessageEventContent;
 
 use crate::admin_command;
@@ -32,15 +32,8 @@ pub(super) async fn reload_config(
 	&self,
 	path: Option<PathBuf>,
 ) -> Result<RoomMessageEventContent> {
-	use conduwuit::config::check;
-
 	let path = path.as_deref().into_iter();
-	let new = Config::load(path).and_then(|raw| Config::new(&raw))?;
-
-	let old = &self.services.server.config;
-	check::reload(old, &new)?;
-
-	self.services.server.config.update(new)?;
+	self.services.config.reload(path)?;
 
 	Ok(RoomMessageEventContent::text_plain("Successfully reconfigured."))
 }

src/core/config/mod.rs

@@ -1742,6 +1742,13 @@ pub struct Config {
 	#[serde(default = "true_fn")]
 	pub listening: bool,
 
+	/// Enables configuration reload when the server receives SIGUSR1 on
+	/// supporting platforms.
+	///
+	/// default: true
+	#[serde(default = "true_fn")]
+	pub config_reload_signal: bool,
+
 	#[serde(flatten)]
 	#[allow(clippy::zero_sized_map_values)]
 	// this is a catchall, the map shouldn't be zero at runtime

src/main/signal.rs

@@ -16,6 +16,7 @@ pub(super) async fn signal(server: Arc<Server>) {
 
 	let mut quit = unix::signal(SignalKind::quit()).expect("SIGQUIT handler");
 	let mut term = unix::signal(SignalKind::terminate()).expect("SIGTERM handler");
+	let mut usr1 = unix::signal(SignalKind::user_defined1()).expect("SIGUSR1 handler");
 	loop {
 		trace!("Installed signal handlers");
 		let sig: &'static str;
@@ -23,6 +24,7 @@ pub(super) async fn signal(server: Arc<Server>) {
 			_ = signal::ctrl_c() => { sig = "SIGINT"; },
 			_ = quit.recv() => { sig = "SIGQUIT"; },
 			_ = term.recv() => { sig = "SIGTERM"; },
+			_ = usr1.recv() => { sig = "SIGUSR1"; },
 		}
 
 		warn!("Received {sig}");

src/service/config/mod.rs

@@ -0,0 +1,55 @@
+use std::{iter, path::Path, sync::Arc};
+
+use async_trait::async_trait;
+use conduwuit::{
+	config::{check, Config},
+	error, implement, Result, Server,
+};
+
+pub struct Service {
+	server: Arc<Server>,
+}
+
+const SIGNAL: &str = "SIGUSR1";
+
+#[async_trait]
+impl crate::Service for Service {
+	fn build(args: crate::Args<'_>) -> Result<Arc<Self>> {
+		Ok(Arc::new(Self { server: args.server.clone() }))
+	}
+
+	async fn worker(self: Arc<Self>) -> Result {
+		while self.server.running() {
+			if self.server.signal.subscribe().recv().await == Ok(SIGNAL) {
+				if let Err(e) = self.handle_reload() {
+					error!("Failed to reload config: {e}");
+				}
+			}
+		}
+
+		Ok(())
+	}
+
+	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
+}
+
+#[implement(Service)]
+fn handle_reload(&self) -> Result {
+	if self.server.config.config_reload_signal {
+		self.reload(iter::empty())?;
+	}
+
+	Ok(())
+}
+
+#[implement(Service)]
+pub fn reload<'a, I>(&self, paths: I) -> Result<Arc<Config>>
+where
+	I: Iterator<Item = &'a Path>,
+{
+	let old = self.server.config.clone();
+	let new = Config::load(paths).and_then(|raw| Config::new(&raw))?;
+
+	check::reload(&old, &new)?;
+	self.server.config.update(new)
+}

src/service/mod.rs

@@ -9,6 +9,7 @@ pub mod account_data;
 pub mod admin;
 pub mod appservice;
 pub mod client;
+pub mod config;
 pub mod emergency;
 pub mod federation;
 pub mod globals;

src/service/services.rs

@@ -10,7 +10,7 @@ use database::Database;
 use tokio::sync::Mutex;
 
 use crate::{
-	account_data, admin, appservice, client, emergency, federation, globals, key_backups,
+	account_data, admin, appservice, client, config, emergency, federation, globals, key_backups,
 	manager::Manager,
 	media, presence, pusher, resolver, rooms, sending, server_keys, service,
 	service::{Args, Map, Service},
@@ -21,6 +21,7 @@ pub struct Services {
 	pub account_data: Arc<account_data::Service>,
 	pub admin: Arc<admin::Service>,
 	pub appservice: Arc<appservice::Service>,
+	pub config: Arc<config::Service>,
 	pub client: Arc<client::Service>,
 	pub emergency: Arc<emergency::Service>,
 	pub globals: Arc<globals::Service>,
@@ -68,6 +69,7 @@ impl Services {
 			appservice: build!(appservice::Service),
 			resolver: build!(resolver::Service),
 			client: build!(client::Service),
+			config: build!(config::Service),
 			emergency: build!(emergency::Service),
 			globals: build!(globals::Service),
 			key_backups: build!(key_backups::Service),