Extensions: New environment variables

README

@@ -164,6 +164,23 @@
 
         export GPODDER_WRITE_LOGS=no
 
+ [ EXTENSIONS ]
+
+    Extensions are normally loaded from gPodder's "extensions/" folder (in
+    share/gpodder/extensions/) and from $GPODDER_HOME/Extensions/ You can
+    override this by setting an environment variable:
+
+        export GPODDER_EXTENSIONS="/path/to/extension1.py extension2.py"
+
+    In addition to that, if you want to disable loading of all extensions,
+    you can do this by setting the following environment variable to a non-
+    empty value:
+
+        export GPODDER_DISABLE_EXTENSIONS=yes
+
+    If you want to report a bug, please try to disable all extensions and
+    check if the bug still appears to see if an extension causes the bug.
+
 
  [ MORE INFORMATION ]
 

src/gpodder/core.py

@@ -34,8 +34,7 @@ class Core(object):
     def __init__(self,
                  config_class=config.Config,
                  database_class=dbsqlite.Database,
-                 model_class=model.Model,
-                 extension_list=[]):
+                 model_class=model.Model):
         # Initialize the gPodder home directory
         util.make_directory(gpodder.home)
 
@@ -45,8 +44,7 @@ class Core(object):
         self.config = config_class(gpodder.config_file)
 
         # Load extension modules and install the extension manager
-        gpodder.user_extensions = extensions.ExtensionManager(self,
-            extension_list=extension_list)
+        gpodder.user_extensions = extensions.ExtensionManager(self)
 
         # Load installed/configured plugins
         gpodder.load_plugins()

src/gpodder/extensions.py

@@ -214,14 +214,18 @@ class ExtensionContainer(object):
 class ExtensionManager(object):
     """Loads extensions and manages self-registering plugins"""
 
-    def __init__(self, core, extension_list=[]):
+    def __init__(self, core):
         self.core = core
-        self.extension_list = extension_list
+        self.filenames = os.environ.get('GPODDER_EXTENSIONS', '').split()
         self.containers = []
 
         core.config.add_observer(self._config_value_changed)
         enabled_extensions = core.config.extensions.enabled
 
+        if os.environ.get('GPODDER_DISABLE_EXTENSIONS', '') != '':
+            logger.info('Disabling all extensions (from environment)')
+            return
+
         for name, filename in self._find_extensions():
             logger.debug('Found extension "%s" in %s', name, filename)
             config = getattr(core.config.extensions, name)
@@ -246,16 +250,18 @@ class ExtensionManager(object):
     def _find_extensions(self):
         extensions = {}
 
-        if self.extension_list:
-            files = self.extension_list
-        else:
+        if not self.filenames:
             builtins = os.path.join(gpodder.prefix, 'share', 'gpodder',
                 'extensions', '*.py')
             user_extensions = os.path.join(gpodder.home, 'Extensions', '*.py')
-            files = glob.glob(builtins) + glob.glob(user_extensions)
+            self.filenames = glob.glob(builtins) + glob.glob(user_extensions)
 
         # Let user extensions override built-in extensions of the same name
-        for filename in files:
+        for filename in self.filenames:
+            if not filename or not os.path.exists(filename):
+                logger.info('Skipping non-existing file: %s', filename)
+                continue
+
             name, _ = os.path.splitext(os.path.basename(filename))
             extensions[name] = filename