python - Google App Engine and 404 error

Question

I've setup a static website on GAE using hints found elsewhere, but can't figure out how to return a 404 error. My app.yaml file looks like

- url: (.*)/
  static_files: static1/index.html
  upload: static/index.html

- url: /
  static_dir: static

with all the static html/jpg files stored under the static directory. The above works for files that exist, but returns a null length file if they don't. The answer is probably to write a python script to return a 404 error, but how do you set things up to serve the static files that exist but run the script for files that don't?

Here is the log from fetching a non-existent file (nosuch.html) on the development application server:

ERROR    2008-11-25 20:08:34,084 dev_appserver.py] Error encountered reading file "/usr/home/ctuffli/www/tufflinet/static/nosuch.html":
[Errno 2] No such file or directory: '/usr/home/ctuffli/www/tufflinet/static/nosuch.html'
INFO     2008-11-25 20:08:34,088 dev_appserver.py] "GET /nosuch.html HTTP/1.1" 404 -

question from:https://stackoverflow.com/questions/189751/google-app-engine-and-404-error

Answer 1

You need to register a catch-all script handler. Append this at the end of your app.yaml:

- url: /.*
  script: main.py

In main.py you will need to put this code:

from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app

class NotFoundPageHandler(webapp.RequestHandler):
    def get(self):
        self.error(404)
        self.response.out.write('<Your 404 error html page>')

application = webapp.WSGIApplication([('/.*', NotFoundPageHandler)],
                                     debug=True)

def main():
    run_wsgi_app(application)

if __name__ == "__main__":
    main()

Replace <Your 404 error html page> with something meaningful. Or better use a template, you can read how to do that here.

Please let me know if you have problems setting this up.