feat: automatically reload configuration when the config file is changed

2025-02-25 18:55:26 -06:00 · 2024-03-17 13:47:45 +02:00
parent e74155515d
commit 16c50970f6
6 changed files with 154 additions and 4 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1241,6 +1241,26 @@ dependencies = [
 "serde",
 ]

+[[package]]
+name = "inotify"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8069d3ec154eb856955c1c0fbffefbf5f3c40a104ec912d4797314c1801abff"
+dependencies = [
+ "bitflags 1.3.2",
+ "inotify-sys",
+ "libc",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.10"
@@ -1256,6 +1276,26 @@ dependencies = [
 "wasm-bindgen",
 ]

+[[package]]
+name = "kqueue"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7447f1ca1b7b563588a205fe93dea8df60fd981423a768bc1c0ded35ed147d0c"
+dependencies = [
+ "kqueue-sys",
+ "libc",
+]
+
+[[package]]
+name = "kqueue-sys"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed9625ffda8729b85e45cf04090035ac368927b8cebc34898e7c120f52e4838b"
+dependencies = [
+ "bitflags 1.3.2",
+ "libc",
+]
+
 [[package]]
 name = "lact"
 version = "0.5.4"
@@ -1302,6 +1342,7 @@ dependencies = [
 "libdrm_amdgpu_sys",
 "libflate",
 "nix",
+ "notify",
 "os-release",
 "pciid-parser",
 "serde",
@@ -1514,6 +1555,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
 dependencies = [
 "libc",
+ "log",
 "wasi",
 "windows-sys 0.48.0",
 ]
@@ -1531,6 +1573,23 @@ dependencies = [
 "memoffset",
 ]

+[[package]]
+name = "notify"
+version = "6.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6205bd8bb1e454ad2e27422015fb5e4f2bcc7e08fa8f27058670d208324a4d2d"
+dependencies = [
+ "bitflags 2.4.2",
+ "filetime",
+ "inotify",
+ "kqueue",
+ "libc",
+ "log",
+ "mio",
+ "walkdir",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.46.0"
@@ -1927,6 +1986,15 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"

+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -2472,6 +2540,16 @@ dependencies = [
 "vk-parse",
 ]

+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
@@ -2548,6 +2626,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"

+[[package]]
+name = "winapi-util"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f29e6f9198ba0d26b4c9f07dbe6f9ed633e1f3d5b8b414090084349e46a52596"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
--- a/lact-daemon/Cargo.toml
+++ b/lact-daemon/Cargo.toml
@@ -38,3 +38,4 @@ tar = "0.4.40"
 libflate = "2.0.0"
 chrono = "0.4.31"
 os-release = "0.1.0"
+notify = { version = "6.1.1", default-features = false }
--- a/lact-daemon/src/config.rs
+++ b/lact-daemon/src/config.rs
@@ -3,10 +3,12 @@ use amdgpu_sysfs::gpu_handle::{PerformanceLevel, PowerLevelKind};
 use anyhow::Context;
 use lact_schema::{default_fan_curve, request::SetClocksCommand, FanControlMode, PmfwOptions};
 use nix::unistd::getuid;
+use notify::{RecommendedWatcher, Watcher};
 use serde::{Deserialize, Serialize};
 use serde_with::skip_serializing_none;
 use std::{collections::HashMap, env, fs, path::PathBuf};
-use tracing::debug;
+use tokio::sync::mpsc;
+use tracing::{debug, error};

 const FILE_NAME: &str = "config.yaml";
 const DEFAULT_ADMIN_GROUPS: [&str; 2] = ["wheel", "sudo"];
@@ -158,6 +160,55 @@ impl Config {
    }
 }

+pub fn start_watcher() -> mpsc::UnboundedReceiver<Config> {
+    let (config_tx, config_rx) = mpsc::unbounded_channel();
+    let (event_tx, event_rx) = std::sync::mpsc::channel();
+
+    tokio::task::spawn_blocking(move || {
+        let mut watcher = RecommendedWatcher::new(event_tx, notify::Config::default())
+            .expect("Could not create config file watcher");
+
+        let config_path = get_path();
+        let watch_path = config_path
+            .parent()
+            .expect("Config path always has a parent");
+        watcher
+            .watch(watch_path, notify::RecursiveMode::Recursive)
+            .expect("Could not subscribe to config file changes");
+
+        for res in event_rx {
+            debug!("got config file event {res:?}");
+            match res {
+                Ok(event) => {
+                    use notify::EventKind;
+
+                    if !event.paths.contains(&config_path) {
+                        continue;
+                    }
+
+                    match event.kind {
+                        EventKind::Modify(_) | EventKind::Create(_) | EventKind::Remove(_) => {
+                            match Config::load() {
+                                Ok(Some(new_config)) => config_tx.send(new_config).unwrap(),
+                                Ok(None) => error!("config was removed!"),
+                                Err(err) => {
+                                    error!("could not read config after it was changed: {err:#}");
+                                }
+                            }
+                        }
+                        _ => (),
+                    }
+                }
+                Err(err) => error!("filesystem event error: {err}"),
+            }
+        }
+
+        debug!("registered config file event listener at path {watch_path:?}");
+    });
+
+    config_rx
+}
+
 fn get_path() -> PathBuf {
    let uid = getuid();
    if uid.is_root() {
--- a/lact-daemon/src/lib.rs
+++ b/lact-daemon/src/lib.rs
@@ -54,6 +54,7 @@ pub fn run() -> anyhow::Result<()> {
                let server = Server::new(config).await?;
                let handler = server.handler.clone();

+                tokio::task::spawn_local(listen_config_changes(handler.clone()));
                tokio::task::spawn_local(listen_exit_signals(handler.clone()));
                tokio::task::spawn_local(suspend::listen_events(handler));
                server.run().await;
@@ -102,6 +103,16 @@ async fn listen_exit_signals(handler: Handler) {
    std::process::exit(0);
 }

+async fn listen_config_changes(handler: Handler) {
+    let mut rx = config::start_watcher();
+    while let Some(new_config) = rx.recv().await {
+        info!("config file was changed, reloading");
+        handler.config.replace(new_config);
+        handler.apply_current_config().await;
+        info!("configuration reloaded");
+    }
+}
+
 async fn ensure_sufficient_uptime() {
    match get_uptime() {
        Ok(current_uptime) => {
--- a/lact-daemon/src/server/handler.rs
+++ b/lact-daemon/src/server/handler.rs
@@ -102,7 +102,7 @@ impl<'a> Handler {
            config: Rc::new(RefCell::new(config)),
            confirm_config_tx: Rc::new(RefCell::new(None)),
        };
-        handler.load_config().await;
+        handler.apply_current_config().await;

        // Eagerly release memory
        // `load_controllers` allocates and deallocates the entire PCI ID database,
@@ -114,7 +114,7 @@ impl<'a> Handler {
        Ok(handler)
    }

-    pub async fn load_config(&self) {
+    pub async fn apply_current_config(&self) {
        let config = self.config.borrow().clone(); // Clone to avoid locking the RwLock on an await point

        for (id, gpu_config) in &config.gpus {
--- a/lact-daemon/src/suspend.rs
+++ b/lact-daemon/src/suspend.rs
@@ -10,7 +10,7 @@ pub async fn listen_events(handler: Handler) {
            Ok(mut stream) => {
                while stream.next().await.is_some() {
                    info!("suspend/resume event detected, reloading config");
-                    handler.load_config().await;
+                    handler.apply_current_config().await;
                }
            }
            Err(err) => error!("could not subscribe to suspend events: {err:#}"),