Add console script to start DDP service in more robust manner than using the dddp Django mangement command (bump version for release: 0.2.3).

CHANGES.rst

@@ -0,0 +1,6 @@
+Change Log
+==========
+
+0.2.3
+-----
+* Add `dddp` console script to start DDP service in more robust manner than using the dddp Django mangement command.

README.rst

@@ -18,7 +18,9 @@ Peer servers subscribe to aggregate broadcast events only for channels (Django m
 
 Limitations
 -----------
-The 0.2.x release series only supports DDP via WebSockets_, version 0.3.0 and beyond are expected to also use SockJS, to support browsers that don't have WebSockets.
+The 0.2.x release series only supports DDP via WebSockets_.  Future
+development may resolve this by using SockJS, to support browsers that
+don't have WebSockets.
 
 Changes must be made via the Django ORM as django-ddp uses `Django signals`_ to receive model save/update signals.
 
@@ -109,7 +111,7 @@ Start the Django DDP service:
 
 .. code:: sh
 
-    manage.py dddp
+    DJANGO_SETTINGS_MODULE=myproject.settings dddp
 
 In a separate terminal, start Meteor (from within your meteor app directory):
 

dddp/__init__.py

@@ -3,7 +3,6 @@ from __future__ import unicode_literals
 import os.path
 from pkg_resources import get_distribution, DistributionNotFound
 from gevent.local import local
-from django.utils.module_loading import autodiscover_modules
 from dddp import alea
 
 try:
@@ -93,6 +92,7 @@ def meteor_random_id(name=None):
 
 
 def autodiscover():
+    from django.utils.module_loading import autodiscover_modules
     from dddp.api import API
     autodiscover_modules('ddp', register_to=API)
     return API

dddp/main.py

@@ -0,0 +1,209 @@
+"""Django DDP WebSocket service."""
+
+from __future__ import print_function, absolute_import
+
+import collections
+import sys
+
+
+Addr = collections.namedtuple('Addr', ['host', 'port'])
+
+
+def greenify():
+    """Patch threading and psycopg2 modules for green threads."""
+    if 'threading' in sys.modules:
+        raise Exception('threading module loaded before patching!')
+
+    from gevent.monkey import patch_all
+    patch_all()
+
+    from psycogreen.gevent import patch_psycopg
+    patch_psycopg()
+
+
+def ddpp_sockjs_xhr(environ, start_response):
+    """Dummy method that doesn't handle XHR requests."""
+    start_response(
+        '404 Not found',
+        [
+            ('Content-Type', 'text/plain; charset=UTF-8'),
+            (
+                'Access-Control-Allow-Origin',
+                '/'.join(environ['HTTP_REFERER'].split('/')[:3]),
+            ),
+            ('Access-Control-Allow-Credentials', 'true'),
+            #  ('access-control-allow-credentials', 'true'),
+            ('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0'),
+            ('Connection', 'keep-alive'),
+            ('Vary', 'Origin'),
+        ],
+    )
+    yield 'No.'
+
+
+def ddpp_sockjs_info(environ, start_response):
+    """Inform client that WebSocket service is available."""
+    import random
+    import ejson
+
+    start_response(
+        '200 OK',
+        [
+            ('Content-Type', 'application/json; charset=UTF-8'),
+            (
+                'Access-Control-Allow-Origin',
+                '/'.join(environ['HTTP_REFERER'].split('/')[:3]),
+            ),
+            ('Access-Control-Allow-Credentials', 'true'),
+            #  ('access-control-allow-credentials', 'true'),
+            ('Cache-Control', 'no-store, no-cache, must-revalidate, max-age=0'),
+            ('Connection', 'keep-alive'),
+            ('Vary', 'Origin'),
+        ],
+    )
+    yield ejson.dumps(collections.OrderedDict([
+        ('websocket', True),
+        ('origins', [
+            '*:*',
+        ]),
+        ('cookie_needed', False),
+        ('entropy', random.getrandbits(32)),
+    ]))
+
+
+def serve(listen, debug=False):
+    """Spawn greenlets for handling websockets and PostgreSQL calls."""
+    import signal
+    from django.db import connection, close_old_connections
+    from django.utils.module_loading import import_string
+    from dddp import autodiscover
+    from dddp.postgres import PostgresGreenlet
+    from dddp.websocket import DDPWebSocketApplication
+    import gevent
+    import geventwebsocket
+
+    # shutdown existing connections
+    close_old_connections()
+
+    # setup PostgresGreenlet to multiplex DB calls
+    postgres = PostgresGreenlet(connection, debug=debug)
+    DDPWebSocketApplication.pgworker = postgres
+
+    # use settings.WSGI_APPLICATION or fallback to default Django WSGI app
+    from django.conf import settings
+    if hasattr(settings, 'WSGI_APPLICATION'):
+        wsgi_name = settings.WSGI_APPLICATION
+        wsgi_app = import_string(wsgi_name)
+    else:
+        from django.core.wsgi import get_wsgi_application
+        wsgi_app = get_wsgi_application()
+        wsgi_name = str(wsgi_app.__class__)
+
+    resource = geventwebsocket.Resource({
+        r'/websocket': DDPWebSocketApplication,
+        r'^/sockjs/\d+/\w+/websocket$': DDPWebSocketApplication,
+        r'^/sockjs/\d+/\w+/xhr$': ddpp_sockjs_xhr,
+        r'^/sockjs/info$': ddpp_sockjs_info,
+        r'^/(?!(websocket|sockjs)/)': wsgi_app,
+    })
+
+    # setup WebSocketServer to dispatch web requests
+    webservers = [
+        geventwebsocket.WebSocketServer(
+            (host, port),
+            resource,
+            debug=debug,
+        )
+        for host, port
+        in listen
+    ]
+
+    def killall(*args, **kwargs):
+        """Kill all green threads."""
+        postgres.stop()
+        for webserver in webservers:
+            webserver.stop()
+
+    # die gracefully with SIGINT or SIGQUIT
+    gevent.signal(signal.SIGINT, killall)
+    gevent.signal(signal.SIGQUIT, killall)
+
+    print('=> Discovering DDP endpoints...')
+    ddp = autodiscover()
+    ddp.pgworker = postgres
+    print(
+        '\n'.join(
+            '    %s' % api_path
+            for api_path
+            in sorted(ddp.api_path_map())
+        ),
+    )
+
+    # start greenlets
+    postgres.start()
+    print('=> Started PostgresGreenlet.')
+    web_threads = [
+        gevent.spawn(webserver.serve_forever)
+        for webserver
+        in webservers
+    ]
+    print('=> Started DDPWebSocketApplication.')
+    print('=> Started your app (%s).' % wsgi_name)
+    print('')
+    for host, port in listen:
+        print('=> App running at: http://%s:%d/' % (host, port))
+    gevent.joinall(web_threads)
+    postgres.stop()
+    gevent.joinall([postgres])
+
+
+def addr(val, default_port=8000, defualt_host='localhost'):
+    """
+    Convert a string of format host[:port] into Addr(host, port).
+
+    >>> addr('0:80')
+    Addr(host='0', port=80)
+
+    >>> addr('127.0.0.1:80')
+    Addr(host='127.0.0.1', port=80)
+
+    >>> addr('0.0.0.0', default_port=8000)
+    Addr(host='0.0.0.0', port=8000)
+    """
+    import re
+    import socket
+
+    match = re.match(r'\A(?P<host>.*?)(:(?P<port>(\d+|\w+)))?\Z', val)
+    if match is None:
+        raise argparse.ArgumentTypeError(
+            '%r is not a valid host[:port] address.' % val
+        )
+    host, port = match.group('host', 'port')
+
+    if not host:
+        host = defualt_host
+
+    if not port:
+        port = default_port
+    elif port.isdigit():
+        port = int(port)
+    else:
+        port = socket.getservbyname(port)
+
+    return Addr(host, port)
+
+
+def main():
+    import argparse
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        'listen', metavar='address[:port]', nargs='*', type=addr,
+    )
+    namespace = parser.parse_args()
+    # monkey patch stdlib for gevent.
+    greenify()
+    serve(namespace.listen or [Addr('localhost', 8000)])
+
+
+if __name__ == '__main__':
+    main()

dddp/postgres.py

@@ -3,10 +3,6 @@
 from __future__ import absolute_import
 
 import collections
-import gevent.monkey
-import psycogreen.gevent
-gevent.monkey.patch_all()
-psycogreen.gevent.patch_psycopg()
 
 import ejson
 import gevent

setup.py

@@ -5,7 +5,7 @@ from setuptools import setup, find_packages
 
 setup(
     name='django-ddp',
-    version='0.2.2',
+    version='0.2.3',
     description=__doc__,
     long_description=open('README.rst').read(),
     author='Tyson Clugg',
@@ -22,6 +22,11 @@ setup(
         'psycogreen>=1.0',
         'django-dbarray>=0.2',
     ],
+    entry_points={
+        'console_scripts': [
+            'dddp=dddp.main:main',
+        ],
+    },
     classifiers=[
         "Programming Language :: Python :: 2",
         "Programming Language :: Python :: 3",