Getting started with Zope on Google App Engine

Thanks to a patch published by Kapil Thangavelu, it's quite straight-forward to get set up to use Zope on Google's App Engine. Yesterday, Guido van Rossum provided a zipimport-implementation which makes it easy to import Python libraries as a ZIP-archive, which was previously not possible in the remote environment.

To make it easier for everyone to get started, I thought I'd publish my setup.

You'll need to dump a ZIP-archive of the packages you want to use in your application directory. Download zope.zip to get the basic necessities.

Put Guido's my_zipimport.py in the Python path and bootstrap the importer using the following code:

  import my_zipimport
  import sys

  my_zipimport.install()
  sys.path.insert(0, 'zope.zip')

You'll probably want to look at Ian Bicking's instructions for getting a Pylons-based application set up and the customize it to point to an application factory such as this:

  import os

  def application_factory(global_conf, zcml='site.zcml', devmode='off', **kwargs):
      zcml_conf = os.path.join(global_conf['here'], zcml)
      devmode = ( devmode.lower() in ('true', 'True', 'on') and True) or False
      return getWSGIApplication(zcml_conf, devmode)

  def getWSGIApplication(configfile, schemafile=None, features=()):
      return WSGIPublisherApplication()

  class WSGIPublisherApplication(object):
      def __call__(self, environ, start_response):
          start_response('200 OK', [('Content-type', 'text/plain')])

          yield "Hello World!"

This is very preliminary, but should give some starting pointers. For an example on how a WSGI application can interact with the Zope publisher, you may want to look at ore.wsgiapp.