feat(server): restart server when config file is updated

Closes kemitix/git-next#59

Cargo.toml

@@ -58,6 +58,9 @@ warp = "0.3"
 derive_more = { version = "1.0.0-beta.6", features = ["from", "display"] }
 terrors = "0.3"
 
+# file watcher
+inotify = "0.10"
+
 # Actors
 actix = "0.13"
 actix-rt = "2.9"

src/server/actors/file_watcher.rs

@@ -0,0 +1,84 @@
+use actix::prelude::*;
+
+use actix::Recipient;
+use inotify::{EventMask, Inotify, WatchMask};
+use std::{path::PathBuf, time::Duration};
+use tracing::{debug, info};
+
+const CHECK_INTERVAL: Duration = Duration::from_secs(1);
+
+#[derive(Debug, Clone)]
+pub struct WatchFile;
+impl Message for WatchFile {
+    type Result = ();
+}
+
+#[derive(Debug)]
+pub struct FileUpdated;
+impl Message for FileUpdated {
+    type Result = ();
+}
+
+#[derive(Debug, derive_more::From, derive_more::Display)]
+pub enum Error {
+    Io(std::io::Error),
+}
+impl std::error::Error for Error {}
+
+pub struct FileWatcher {
+    path: PathBuf,
+    inotify: Inotify,
+    recipient: Recipient<FileUpdated>,
+    run_interval: Option<SpawnHandle>,
+}
+impl FileWatcher {
+    pub fn new(path: PathBuf, recipient: Recipient<FileUpdated>) -> Result<Self, Error> {
+        let inotify = Inotify::init()?;
+        inotify.watches().add(
+            path.clone(),
+            WatchMask::MODIFY | WatchMask::CREATE | WatchMask::DELETE,
+        )?;
+        Ok(Self {
+            path,
+            inotify,
+            recipient,
+            run_interval: None,
+        })
+    }
+}
+impl Actor for FileWatcher {
+    type Context = Context<Self>;
+
+    fn started(&mut self, ctx: &mut Self::Context) {
+        info!("Starting file watcher actor");
+        self.run_interval
+            .replace(ctx.run_interval(CHECK_INTERVAL, |_act, ctx| {
+                ctx.notify(WatchFile);
+            }));
+    }
+}
+
+impl Handler<WatchFile> for FileWatcher {
+    type Result = ();
+
+    fn handle(&mut self, _msg: WatchFile, _ctx: &mut Self::Context) -> Self::Result {
+        debug!("Watching {} for activity...", self.path.display());
+        let mut buffer = [0u8; 4096];
+        if let Ok(mut events) = self.inotify.read_events(&mut buffer) {
+            if events.any(|event| event.mask.contains(EventMask::MODIFY)) {
+                info!("File modified");
+                self.recipient.do_send(FileUpdated);
+            };
+        }
+    }
+}
+// impl Handler<Stop> for FileWatcher {
+//     type Result = anyhow::Result<()>;
+//
+//     fn handle(&mut self, _msg: Stop, ctx: &mut Self::Context) -> Self::Result {
+//         warn!("Stopping file watcher actor");
+//         self.run_interval.take();
+//         ctx.stop();
+//         Ok(())
+//     }
+// }

src/server/actors/mod.rs

@@ -1,3 +1,4 @@
+pub mod file_watcher;
 pub mod repo;
 pub mod server;
 pub mod webhook;

src/server/actors/server.rs

@@ -7,8 +7,9 @@ use tracing::{error, info};
 
 use crate::server::{
     actors::{
+        file_watcher::FileUpdated,
         repo::{CloneRepo, RepoActor},
-        webhook::{AddWebhookRecipient, WebhookActor, WebhookRouter},
+        webhook::{AddWebhookRecipient, ShutdownWebhook, WebhookActor, WebhookRouter},
     },
     config::{
         ForgeConfig, ForgeName, GitDir, RepoAlias, RepoDetails, ServerConfig, ServerRepoConfig,
@@ -35,17 +36,36 @@ type Result<T> = core::result::Result<T, Error>;
 
 pub struct Server {
     generation: ServerGeneration,
+    webhook: Option<Addr<WebhookActor>>,
     fs: FileSystem,
     net: Network,
 }
 impl Actor for Server {
     type Context = Context<Self>;
 }
+impl Handler<FileUpdated> for Server {
+    type Result = ();
+
+    fn handle(&mut self, _msg: FileUpdated, ctx: &mut Self::Context) -> Self::Result {
+        let server_config = match ServerConfig::load(&self.fs) {
+            Ok(server_config) => server_config,
+            Err(err) => {
+                error!("Failed to load config file. Error: {}", err);
+                return;
+            }
+        };
+        ctx.notify(server_config);
+    }
+}
 impl Handler<ServerConfig> for Server {
     type Result = ();
 
     #[allow(clippy::cognitive_complexity)] // TODO: (#75) reduce complexity
     fn handle(&mut self, msg: ServerConfig, _ctx: &mut Self::Context) -> Self::Result {
+        if let Some(webhook) = self.webhook.take() {
+            webhook.do_send(ShutdownWebhook);
+        }
+        self.generation.inc();
         let server_config = msg;
         // Server Storage
         let dir = server_config.storage().path();
@@ -83,13 +103,16 @@ impl Handler<ServerConfig> for Server {
                 .for_each(|msg| webhook_router.do_send(msg));
         }
 
-        WebhookActor::new(webhook_router.recipient()).start();
+        let webhook = WebhookActor::new(webhook_router.recipient()).start();
+        self.webhook.replace(webhook);
     }
 }
 impl Server {
-    pub const fn new(generation: ServerGeneration, fs: FileSystem, net: Network) -> Self {
+    pub fn new(fs: FileSystem, net: Network) -> Self {
+        let generation = ServerGeneration::new();
         Self {
             generation,
+            webhook: None,
             fs,
             net,
         }

src/server/actors/webhook/mod.rs

@@ -37,3 +37,17 @@ impl Actor for WebhookActor {
         self.spawn_handle.replace(spawn_handle);
     }
 }
+
+#[derive(Debug)]
+pub struct ShutdownWebhook;
+impl Message for ShutdownWebhook {
+    type Result = ();
+}
+impl Handler<ShutdownWebhook> for WebhookActor {
+    type Result = ();
+
+    fn handle(&mut self, _msg: ShutdownWebhook, ctx: &mut Self::Context) -> Self::Result {
+        self.spawn_handle.take();
+        ctx.stop();
+    }
+}

src/server/mod.rs

@@ -13,7 +13,10 @@ use tracing::{error, info, level_filters::LevelFilter};
 
 use crate::{
     fs::FileSystem,
-    server::{actors::server::Server, types::ServerGeneration},
+    server::actors::{
+        file_watcher::{self, FileUpdated},
+        server::Server,
+    },
 };
 
 pub fn init(fs: FileSystem) {
@@ -40,22 +43,21 @@ pub fn init(fs: FileSystem) {
 
 pub async fn start(fs: FileSystem, net: Network) {
     init_logging();
-    let generation = ServerGeneration::new();
-    {
-        let span = tracing::info_span!("Server", %generation);
-        let _guard = span.enter();
-        info!("Starting Server...");
-        let server_config = match config::ServerConfig::load(&fs) {
-            Ok(server_config) => server_config,
-            Err(err) => {
-                error!("Failed to load config file. Error: {}", err);
-                return;
-            }
-        };
 
-        let server = Server::new(generation, fs.clone(), net.clone()).start();
-        server.do_send(server_config);
-    }
+    info!("Starting Server...");
+    let server = Server::new(fs.clone(), net.clone()).start();
+    server.do_send(FileUpdated);
+
+    info!("Starting File Watcher...");
+    let fw = match file_watcher::FileWatcher::new("git-next-server.toml".into(), server.recipient())
+    {
+        Ok(fw) => fw,
+        Err(err) => {
+            error!(?err, "Failed to start file watcher");
+            return;
+        }
+    };
+    fw.start();
 
     info!("Server running - Press Ctrl-C to stop...");
     let _ = actix_rt::signal::ctrl_c().await;

src/server/types.rs

@@ -42,8 +42,8 @@ impl ServerGeneration {
     pub fn new() -> Self {
         Self::default()
     }
-    pub const fn next(&self) -> Self {
-        Self(self.0 + 1)
+    pub fn inc(&mut self) {
+        self.0 += 1
     }
 }
 impl std::fmt::Display for ServerGeneration {