How to call an instance of webapp.RequestHandler class inside other module? - google-app-engine

Question

I am trying to create a simple web application using Google App Engine. I use jinja2 to render a frontend html file. User enters their AWS credentials and gets the output of regions and connected with them virtual machines.
I have a controller file, to which I import a model file and it looks like this:
import webapp2
import jinja2
import os
import model
jinja_environment = jinja2.Environment(loader=jinja2.FileSystemLoader(os.path.dirname(__file__)))
class MainPage(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('index.html')
self.response.out.write(template.render())
def request_a(self):
a = self.reguest.get('a')
return a
def request_b(self):
b = self.reguest.get('b')
return b
class Responce(webapp2.RequestHandler):
def get(self):
self.response.headers['Content-Type'] = 'text/plain'
self.response.write(testing_ec2.me.get_machines())
app = webapp2.WSGIApplication([('/2', MainPage), ('/responce', Responce)], debug=True)
then I have a model file, to which I import controller file and it looks like this:
import boto.ec2
import controller
import sys
if not boto.config.has_section('Boto'):
boto.config.add_section('Boto')
boto.config.set('Boto', 'https_validate_certificates', 'False')
a = controller.MainPage.get()
b = controller.MainPage.get()
class VM(object):
def __init__(self, a, b):
self.a = a
self.b = b
self.regions = boto.ec2.regions(aws_access_key_id = a, aws_secret_access_key = b)
def get_machines(self):
self.region_to_instance = {}#dictionary, which matches regions and instances for this region
for region in self.regions:
conn = region.connect(aws_access_key_id = self.a, aws_secret_access_key = self.b)
reservations = conn.get_all_instances()#get reservations(need understand them better)
if len(reservations) > 0:#if there are reservations in this region
self.instances = [i for r in reservations for i in r.instances]#creates a list of instances for that region
self.region_to_instance[region.name] = self.instances
return self.region_to_instance
me = VM(a, b)
me.get_machines()
When I run this, it throws an error: type object 'MainPage' has no attribute 'request_a'
I assume, that it happens, because I do not call an instance of MainPage class and instead call a class itself. What is an instance of MainPage(and it`s parent webapp.RequestHandler) class? How do I call it inside another module?

Answer 1

Your code looks very strange to me. I do not understand your coding practice.
The general answer is : if you like to use methods of your MainPage, you can use inheritance.
But. If I understand the goal of your code. Why not call boto from your Responce class. But, here you use a get, where you should use a post, because you post a form with AWS credentials.
So I suggest :
create a MainPage with get and post methods to handle the form
in the the post method make the boto requests and send the result with jinja to the user.
See also Getting started with GAE Python27 and handling forms:
https://developers.google.com/appengine/docs/python/gettingstartedpython27/handlingforms?hl=nl