Add your custom templates to your template directory and name them 404.html, 500.html etc.

Paste the following into middleware/errorpages.py

class DummyUser(object):

    def get_and_delete_messages(self):
        pass

class NeedsUserObject(object):

    def process_request(self, request):
        request.user = DummyUser()

In your settings.py add the NeedsUserObject middleware

MIDDLEWARE_CLASSES = (
  ...
    'middleware.errorpages.NeedsUserObject',
)

Update: Aprill 11 – Added toggle_debug, automatically switches debug off when publishing and back on for development.

#!/usr/bin/env python
#
# Simple convience script for common publishing and develop tasks
# This script expects dev_appserver.py to be in your $PATH
import os, sys, re

def main(argv):

    command = ""

    try:
        command = argv[1]
    except:
        usage()
        exit(2)

    if command == 'publish':
        publish()
    elif command == 'publish-debug':
        publish(True)
    elif command == 'runserver':
        runserver()
    elif command == "--help" or command == "-h":
        usage()
        exit(0)

def usage():
    print """
    Usage: python manage.py [command] 

    Commands:
        publish - 'updates' Google App Engine with your current version
        publish-debug - 'updates' Goolge App Engine with debug turned on
        runserver - launches the development server on port 8080

    Options:
        --help, -h - Prints this screen

    For more information on a particular command, run [command] --help
    """
def get_gae_dir():
    """ Locate dev_appserver.py and return the directory is in. """

    # There's probably a smarter way to do this...
    script = 'dev_appserver.py'
    stdin, stdout = os.popen2('which %s'%script)
    xpath = stdout.read().strip()
    stdout.close()
    stdin.close()

    # If the file is a symlink, find out where the actual file lives.
    try:
        tmpdir = os.readlink(xpath)
    except OSError:
        tmpdir = xpath

    return os.path.abspath(os.path.dirname(tmpdir))

def toggle_debug(status):
    st = 'False'
    if status:
        st = 'True'

    os.rename('settings.py','settings.py.bak')
    orig = open('settings.py.bak').read()
    p = re.compile('DEBUG\s=\s(True|False)')
    n = p.sub('DEBUG = %s'%st,orig)
    nw = open('settings.py','w')
    nw.write(n)
    nw.close()

def gae_parent(script):

    DIR_PATH = get_gae_dir()
    DEV_APPSERVER_PATH = os.path.join(DIR_PATH,'google/appengine/tools/%s'%script)

    EXTRA_PATHS = [
      DIR_PATH,
      os.path.join(DIR_PATH, 'lib', 'django'),
      os.path.join(DIR_PATH, 'lib', 'webob'),
      os.path.join(DIR_PATH, 'lib', 'yaml', 'lib'),
    ]

    sys.path = EXTRA_PATHS + sys.path
    execfile(DEV_APPSERVER_PATH, globals())

def publish(debug=False):

    if(debug):
        toggle_debug(True)
    else:
        toggle_debug(False)

    sys.argv[1] = "update"
    try:
        sys.argv[2] = os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
    except IndexError:
        sys.argv.append(os.path.abspath(os.path.dirname(os.path.realpath(__file__))))

    gae_parent('appcfg.py')

def runserver():
    toggle_debug(True)
    sys.argv[1] = os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
    gae_parent('dev_appserver_main.py')

if __name__ == '__main__':
    main(sys.argv)

• Python Only – This doesn’t bother me, but is still a deal breaker for a lot of people.
• No way to schedule tasks. (cron)
• No way to dynamically route subdomains. You can’t point *.yourdomain.com at a single script. So your urls have to look like example.com/tulsa and not tulsa.example.com
• You can’t use any existing libraries that make network fetches. Google forces you to use their URL Fetcher class. Which is broken in several ways:
  • No way to set timeout
  • No HTTP Auth Support
  • Does not follow redirects
• You have to user BigTable for your Database Layer, so you have to port any existing database code you have. There is also no ORM for Django to use BigTable yet, which means Django Admin interface will not work.

On the bright side, their publishing and versioning process is outstanding. The administration interface is pretty sexy so I’ve take quite a few screen shots for anyone who didn’t get an invite and would like to see it.