Implement gmg serve and gmg celery.

There was an existing stub for `gmg serve`, but had never been completed.

This will make it simpler to run the MediaGoblin web interface and media
processing backend.

mediagoblin/gmg_commands/__init__.py

@@ -70,6 +70,10 @@ SUBCOMMAND_MAP = {
             'setup': 'mediagoblin.gmg_commands.serve:parser_setup',
             'func': 'mediagoblin.gmg_commands.serve:serve',
             'help': 'PasteScript replacement'},
+    'celery': {
+        'setup': 'mediagoblin.gmg_commands.celery:parser_setup',
+        'func': 'mediagoblin.gmg_commands.celery:celery',
+        'help': 'Run the celery media processing backend'},
     'batchaddmedia': {
         'setup': 'mediagoblin.gmg_commands.batchaddmedia:parser_setup',
         'func': 'mediagoblin.gmg_commands.batchaddmedia:batchaddmedia',

mediagoblin/gmg_commands/celery.py

@@ -0,0 +1,36 @@
+# GNU MediaGoblin -- federated, autonomous media hosting
+# Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+from celery import current_app
+
+
+def parser_setup(subparser):
+    # No arguments as celery is configured through mediagoblin.ini and
+    # paste.ini.
+    pass
+
+
+def celery(args):
+    os.environ['CELERY_CONFIG_MODULE'] = 'mediagoblin.init.celery.from_celery'
+    from mediagoblin.init.celery.from_celery import setup_self
+
+    # We run setup_self() to initialise Celery with its queue config and set of
+    # tasks. That doesn't return anything, so we pick up the configured celery
+    # via current_app (kinda scary to manage state like this but oh well).
+    setup_self()
+    worker = current_app.Worker()
+    worker.start()

mediagoblin/gmg_commands/serve.py

@@ -14,33 +14,14 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
 
-from paste.deploy import loadapp, loadserver
-
-
-class ServeCommand:
-
-    def loadserver(self, server_spec, name, relative_to, **kwargs):
-        return loadserver(server_spec, name=name, relative_to=relative_to,
-                          **kwargs)
-
-    def loadapp(self, app_spec, name, relative_to, **kwargs):
-        return loadapp(app_spec, name=name, relative_to=relative_to, **kwargs)
-
-    def daemonize(self):
-        pass
-
-    def restart_with_reloader(self):
-        pass
-
-    def restart_with_monitor(self, reloader=False):
-        pass
-
-    def run(self):
-        print('Running...')
+from paste.script.command import get_commands, invoke
 
 
 def parser_setup(subparser):
+    # Duplicating these arguments so that `gmg serve` will accept them and
+    # provide command-line help. We don't actually used the parsed arguments.
     subparser.add_argument('config', metavar='CONFIG_FILE')
     subparser.add_argument('command',
                            choices=['start', 'stop', 'restart', 'status'],
@@ -60,5 +41,24 @@ def parser_setup(subparser):
 
 
 def serve(args):
-    serve_cmd = ServeCommand()  # TODO: pass args to it
-    serve_cmd.run()
+    # Option 1: Run Paste Script's ServeCommand from Python.
+    #
+    # Taking the lead from paste.script.command.run and re-using their "serve"
+    # command. We don't have an easy way to feed the already parsed arguments
+    # through though, so we're pulling these directly from argv.
+    args = sys.argv
+    args_after_subcommand = args[args.index('serve') + 1:]
+    command = get_commands()['serve'].load()
+    invoke(command, 'serve', {}, args_after_subcommand)
+
+    # Option 2: Serve with Waitress.
+    #
+    # Works but has no reloading capabilities but unlike Paste Script doesn't know where to
+    # find the static files.
+    #
+    # Hupper has an example of waitress + reloading:
+    # https://docs.pylonsproject.org/projects/hupper/en/master/#api-usage
+    # from mediagoblin.app import MediaGoblinApp
+    # from waitress import serve
+    # app = MediaGoblinApp('mediagoblin.ini')
+    # serve(app, listen='*:6543')