Merge pull request #2758 from didier-wenzek/fix/inotify-on-symlink

feat(watcher): use canonical path when watching a directory

Author: reubenmiller

crates/common/tedge_utils/src/notify.rs

@@ -144,9 +144,11 @@ impl NotifyStream {
 
     /// Will return an error if you try to watch a file/directory which doesn't exist
     pub fn add_watcher(&mut self, dir_path: &Path) -> Result<(), NotifyStreamError> {
+        // Try to use canonical paths to avoid false negatives when dealing with symlinks
+        let dir_path = dir_path.canonicalize()?;
         self.debouncer
             .watcher()
-            .watch(dir_path, RecursiveMode::Recursive)?;
+            .watch(&dir_path, RecursiveMode::Recursive)?;
 
         Ok(())
     }

crates/extensions/tedge_file_system_ext/src/lib.rs

@@ -84,8 +84,9 @@ impl Default for FsWatchActorBuilder {
 }
 
 impl MessageSource<FsWatchEvent, PathBuf> for FsWatchActorBuilder {
-    fn register_peer(&mut self, config: PathBuf, sender: DynSender<FsWatchEvent>) {
-        self.watch_dirs.push((config, sender));
+    fn register_peer(&mut self, path: PathBuf, sender: DynSender<FsWatchEvent>) {
+        let path = path.canonicalize().unwrap_or_else(|_| path.to_path_buf());
+        self.watch_dirs.push((path, sender));
     }
 }
 
@@ -173,12 +174,15 @@ mod tests {
 
     #[tokio::test(flavor = "multi_thread")]
     async fn test_fs_events() -> Result<(), DynError> {
-        let ttd = TempTedgeDir::new();
+        let temp = TempTedgeDir::new();
+        let ttd = temp.dir("watched-dir");
+        let ttd_link = temp.link_dir(&ttd, "watched-symlink");
+        let ttd_full = ttd.to_path_buf().canonicalize().unwrap().to_path_buf();
         let mut fs_actor_builder = FsWatchActorBuilder::new();
         let client_builder: SimpleMessageBoxBuilder<FsWatchEvent, NoMessage> =
             SimpleMessageBoxBuilder::new("FS Client", 5);
 
-        fs_actor_builder.register_peer(ttd.to_path_buf(), client_builder.get_sender());
+        fs_actor_builder.register_peer(ttd_link.to_path_buf(), client_builder.get_sender());
 
         let actor = fs_actor_builder.build();
         let client_box = client_builder.build();
@@ -195,9 +199,9 @@ mod tests {
         client_box
             .with_timeout(TEST_TIMEOUT)
             .assert_received_unordered([
-                FsWatchEvent::Modified(ttd.to_path_buf().join("file_a")),
-                FsWatchEvent::DirectoryCreated(ttd.to_path_buf().join("dir_b")),
-                FsWatchEvent::Modified(ttd.to_path_buf().join("dir_b").join("file_b")),
+                FsWatchEvent::Modified(ttd_full.to_path_buf().join("file_a")),
+                FsWatchEvent::DirectoryCreated(ttd_full.to_path_buf().join("dir_b")),
+                FsWatchEvent::Modified(ttd_full.to_path_buf().join("dir_b").join("file_b")),
             ])
             .await;
 

crates/tests/tedge_test_utils/src/fs.rs

@@ -60,6 +60,22 @@ impl TempTedgeDir {
         TempTedgeFile { file_path: path }
     }
 
+    pub fn link_dir(&self, original: &TempTedgeDir, link_name: &str) -> TempTedgeDir {
+        let root = Utf8Path::from_path(self.temp_dir.path()).unwrap();
+        let path = root.join(&self.current_file_path).join(link_name);
+
+        #[cfg(unix)]
+        std::os::unix::fs::symlink(original.path(), &path).unwrap();
+
+        #[cfg(windows)]
+        std::os::windows::fs::symlink_dir(original.path(), &path).unwrap();
+
+        TempTedgeDir {
+            temp_dir: self.temp_dir.clone(),
+            current_file_path: path,
+        }
+    }
+
     pub fn path(&self) -> &Path {
         self.current_file_path.as_std_path()
     }