Fixed #16360 -- Added WSGI entrypoint to startproject layout, and enabled internal servers (runserver and runfcgi) to use an externally-defined WSGI application. Thanks to Armin Ronacher, Jannis Leidel, Alex Gaynor, ptone, and Jacob Kaplan-Moss.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17022 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/handlers/base.py

@@ -242,8 +242,8 @@ def get_script_name(environ):
     Returns the equivalent of the HTTP request's SCRIPT_NAME environment
     variable. If Apache mod_rewrite has been used, returns what would have been
     the script name prior to any rewriting (so it's the script name as seen
-    from the client's perspective), unless FORCE_SCRIPT_NAME is set (to
-    anything).
+    from the client's perspective), unless the FORCE_SCRIPT_NAME setting is
+    set (to anything).
     """
     from django.conf import settings
     if settings.FORCE_SCRIPT_NAME is not None:

django/core/handlers/wsgi.py

@@ -124,6 +124,7 @@ class LimitedStream(object):
         self.buffer = sio.read()
         return line
 
+
 class WSGIRequest(http.HttpRequest):
     def __init__(self, environ):
         script_name = base.get_script_name(environ)
@@ -202,13 +203,12 @@ class WSGIRequest(http.HttpRequest):
     FILES = property(_get_files)
     REQUEST = property(_get_request)
 
+
 class WSGIHandler(base.BaseHandler):
     initLock = Lock()
     request_class = WSGIRequest
 
     def __call__(self, environ, start_response):
-        from django.conf import settings
-
         # Set up middleware if needed. We couldn't do this earlier, because
         # settings weren't available.
         if self._request_middleware is None:
@@ -253,4 +253,3 @@ class WSGIHandler(base.BaseHandler):
             response_headers.append(('Set-Cookie', str(c.output(header=''))))
         start_response(status, response_headers)
         return response
-

django/core/management/commands/runserver.py

@@ -5,8 +5,7 @@ import sys
 import socket
 
 from django.core.management.base import BaseCommand, CommandError
-from django.core.handlers.wsgi import WSGIHandler
-from django.core.servers.basehttp import AdminMediaHandler, run, WSGIServerException
+from django.core.servers.basehttp import AdminMediaHandler, run, WSGIServerException, get_internal_wsgi_application
 from django.utils import autoreload
 
 naiveip_re = re.compile(r"""^(?:
@@ -37,7 +36,7 @@ class BaseRunserverCommand(BaseCommand):
         """
         Returns the default WSGI handler for the runner.
         """
-        return WSGIHandler()
+        return get_internal_wsgi_application()
 
     def handle(self, addrport='', *args, **options):
         self.use_ipv6 = options.get('use_ipv6')

django/core/servers/basehttp.py

@@ -18,7 +18,10 @@ from wsgiref import simple_server
 from wsgiref.util import FileWrapper   # for backwards compatibility
 
 import django
+from django.core.exceptions import ImproperlyConfigured
 from django.core.management.color import color_style
+from django.core.wsgi import get_wsgi_application
+from django.utils.importlib import import_module
 from django.utils._os import safe_join
 from django.views import static
 
@@ -27,6 +30,43 @@ from django.contrib.staticfiles import handlers
 __all__ = ['WSGIServer', 'WSGIRequestHandler']
 
 
+def get_internal_wsgi_application():
+    """
+    Loads and returns the WSGI application as configured by the user in
+    ``settings.WSGI_APPLICATION``. With the default ``startproject`` layout,
+    this will be the ``application`` object in ``projectname/wsgi.py``.
+
+    This function, and the ``WSGI_APPLICATION`` setting itself, are only useful
+    for Django's internal servers (runserver, runfcgi); external WSGI servers
+    should just be configured to point to the correct application object
+    directly.
+
+    If settings.WSGI_APPLICATION is not set (is ``None``), we just return
+    whatever ``django.core.wsgi.get_wsgi_application`` returns.
+
+    """
+    from django.conf import settings
+    app_path = getattr(settings, 'WSGI_APPLICATION')
+    if app_path is None:
+        return get_wsgi_application()
+    module_name, attr = app_path.rsplit('.', 1)
+    try:
+        mod = import_module(module_name)
+    except ImportError, e:
+        raise ImproperlyConfigured(
+            "WSGI application '%s' could not be loaded; "
+            "could not import module '%s': %s" % (app_path, module_name, e))
+    try:
+        app = getattr(mod, attr)
+    except AttributeError, e:
+        raise ImproperlyConfigured(
+            "WSGI application '%s' could not be loaded; "
+            "can't find '%s' in module '%s': %s"
+            % (app_path, attr, module_name, e))
+
+    return app
+
+
 class WSGIServerException(Exception):
     pass
 

django/core/servers/fastcgi.py

@@ -139,7 +139,7 @@ def runfastcgi(argset=[], **kwargs):
         return False
 
     # Prep up and go
-    from django.core.handlers.wsgi import WSGIHandler
+    from django.core.servers.basehttp import get_internal_wsgi_application
 
     if options["host"] and options["port"] and not options["socket"]:
         wsgi_opts['bindAddress'] = (options["host"], int(options["port"]))
@@ -178,7 +178,7 @@ def runfastcgi(argset=[], **kwargs):
         fp.write("%d\n" % os.getpid())
         fp.close()
 
-    WSGIServer(WSGIHandler(), **wsgi_opts).run()
+    WSGIServer(get_internal_wsgi_application(), **wsgi_opts).run()
 
 if __name__ == '__main__':
     runfastcgi(sys.argv[1:])

django/core/wsgi.py

@@ -0,0 +1,13 @@
+from django.core.handlers.wsgi import WSGIHandler
+
+
+def get_wsgi_application():
+    """
+    The public interface to Django's WSGI support. Should return a WSGI
+    callable.
+
+    Allows us to avoid making django.core.handlers.WSGIHandler public API, in
+    case the internal WSGI implementation changes or moves in the future.
+
+    """
+    return WSGIHandler()