app: During startup, run post-init operation in background

- This allows for the service to become "ready" and serving web connection sooner.

- If some operations such as obtaining certificates and domain configurations
are happening, these can be shown as operations with UI notifications.

Tests:

- Running 'freedombox-develop --setup' works. 'App initialization completed'
message is printed before 'Running setup...' message. Process exits
successfully.

- Running 'freedombox-develop --setup-no-install' works. 'App initialization
completed' message is printed before 'Running setup...' message. Process exits
successfully.

- Running 'freedombox-develop' works. 'App initialization completed' message is
printed before 'Running regular setup' and 'Setup finished'. Cherrypy starts
listening before 'App initialization completed' message.

- Running a fresh VM setup works.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/__main__.py

@@ -4,6 +4,7 @@
 import argparse
 import logging
 import sys
+import threading
 
 from . import __version__
 from . import app as app_module
@@ -95,6 +96,13 @@ def on_web_server_stop():
     glib.stop()
 
 
+def run_post_init_and_setup():
+    """Run post-init operations on the apps and setup operations."""
+    app_module.apps_post_init()
+    frontpage.add_custom_shortcuts()
+    setup.run_setup_on_startup()  # Long running, retrying
+
+
 def main():
     """Initialize and start the application"""
     arguments = parse_arguments()
@@ -134,16 +142,16 @@ def main():
 
     module_loader.load_modules()
     app_module.apps_init()
-    app_module.apps_post_init()
-    frontpage.add_custom_shortcuts()
 
     if arguments.setup is not False:
+        app_module.apps_post_init()
         run_setup_and_exit(arguments.setup, allow_install=True)
 
     if arguments.setup_no_install is not False:
+        app_module.apps_post_init()
         run_setup_and_exit(arguments.setup_no_install, allow_install=False)
 
-    setup.run_setup_in_background()
+    threading.Thread(target=run_post_init_and_setup).start()
 
     glib.run()
 

plinth/setup.py

@@ -26,7 +26,6 @@ from .privileged import packages as packages_privileged
 
 logger = logging.getLogger(__name__)
 
-_is_first_setup = False
 is_first_setup_running = False
 _is_shutting_down = False
 
@@ -273,18 +272,15 @@ def list_dependencies(app_ids=None, essential=False):
                 print(package_expression)
 
 
-def run_setup_in_background():
-    """Run setup in a background thread."""
-    _set_is_first_setup()
-    threading.Thread(target=_run_setup_on_startup).start()
-
-
-def _run_setup_on_startup():
+def run_setup_on_startup():
     """Run setup with retry till it succeeds."""
+    is_first_setup = any((app for app in app_module.App.list()
+                          if app.info.is_essential and app.needs_setup()))
+
     sleep_time = 10
     while True:
         try:
-            if _is_first_setup:
+            if is_first_setup:
                 logger.info('Running first setup.')
                 _run_first_setup()
                 break
@@ -299,7 +295,7 @@ def _run_setup_on_startup():
             if _is_shutting_down:
                 break
 
-    logger.info('Setup thread finished.')
+    logger.info('Setup finished.')
 
 
 def _run_first_setup():
@@ -337,13 +333,6 @@ def _get_apps_for_regular_setup():
     ]
 
 
-def _set_is_first_setup():
-    """Set whether all essential apps have been setup at least once."""
-    global _is_first_setup
-    _is_first_setup = any((app for app in app_module.App.list()
-                           if app.info.is_essential and app.needs_setup()))
-
-
 def run_setup_on_apps(app_ids, allow_install=True):
     """Run setup on the given list of apps.