main: List dependencies without writing to disk

- Don't run the second phase of web framework initialization. This avoids
writing to the DB file.

- Set log level to ERROR so that no messages get printed even to stderr while
listing dependencies.

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

plinth/__main__.py

@@ -129,6 +129,11 @@ def main():
 
     adapt_config(arguments)
 
+    if arguments.list_dependencies is not False:
+        log.default_level = 'ERROR'
+        web_framework.init(read_only=True)
+        list_dependencies(arguments.list_dependencies)
+
     log.init()
 
     web_framework.init()
@@ -152,9 +157,6 @@ def main():
     if arguments.setup_no_install is not False:
         run_setup_and_exit(arguments.setup_no_install, allow_install=False)
 
-    if arguments.list_dependencies is not False:
-        list_dependencies(arguments.list_dependencies)
-
     if arguments.list_modules is not False:
         list_modules(arguments.list_modules)
 

plinth/setup.py

@@ -3,6 +3,7 @@
 Utilities for performing application setup operations.
 """
 
+import importlib
 import logging
 import os
 import threading
@@ -207,7 +208,9 @@ def setup_modules(module_list=None, essential=False, allow_install=True):
 
 def list_dependencies(module_list=None, essential=False):
     """Print list of packages required by selected or essential modules."""
-    for module_name, module in plinth.module_loader.loaded_modules.items():
+    for module_import_path in plinth.module_loader.get_modules_to_load():
+        module_name = module_import_path.split('.')[-1]
+        module = importlib.import_module(module_import_path)
         if essential and not _is_module_essential(module):
             continue