[App] Resolve race condition to move ui files (#15398)

Author: tchaton

src/lightning_app/CHANGELOG.md

@@ -68,6 +68,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Fixed an issue with the `lightning` CLI taking a long time to error out when the cloud is not reachable ([#15412](https://github.com/Lightning-AI/lightning/pull/15412))
 
 
+- Fixed race condition to over-write the frontend with app infos ([#15398](https://github.com/Lightning-AI/lightning/pull/15398))
+
+
 
 ## [1.8.0] - 2022-11-01
 

src/lightning_app/core/app.py

@@ -100,6 +100,7 @@ def __init__(
         """
 
         self.root_path = root_path  # when running behind a proxy
+        self.info = info
 
         from lightning_app.core.flow import _RootFlow
 
@@ -168,9 +169,10 @@ def __init__(
 
         logger.debug(f"ENV: {os.environ}")
 
+    def _update_index_file(self):
         # update index.html,
         # this should happen once for all apps before the ui server starts running.
-        frontend.update_index_file(FRONTEND_DIR, info=info, root_path=root_path)
+        frontend.update_index_file(FRONTEND_DIR, info=self.info, root_path=self.root_path)
 
         if _should_dispatch_app():
             os.environ["LIGHTNING_DISPATCHED"] = "1"

src/lightning_app/runners/cloud.py

@@ -99,6 +99,7 @@ def dispatch(
         app_config = AppConfig.load_from_file(config_file) if config_file else AppConfig()
         root = config_file.parent if config_file else Path(self.entrypoint_file).absolute().parent
         cleanup_handle = _prepare_lightning_wheels_and_requirements(root)
+        self.app._update_index_file()
         repo = LocalSourceCodeDir(path=root)
         self._check_uploaded_folder(root, repo)
         requirements_file = root / "requirements.txt"

src/lightning_app/runners/multiprocess.py

@@ -30,9 +30,11 @@ def dispatch(self, *args: Any, on_before_run: Optional[Callable] = None, **kwarg
         """Method to dispatch and run the LightningApp."""
         try:
             _set_flow_context()
+
             self.app.backend = self.backend
             self.backend._prepare_queues(self.app)
             self.backend.resolve_url(self.app, "http://127.0.0.1")
+            self.app._update_index_file()
 
             # set env variables
             os.environ.update(self.env_vars)