Setting up Django on Google App Engine for DataStore - django

How do I setup Django on Google App Engine to use DataStore? I did a bunch of searches and some seemed to point to something called django-nonrel. But I couldn't find anything that looked like a definitive guide up-to-date (dated around 2012-2013).

The djangae project seems to be what you're looking for. From their documentation:
Djangae (jan-gee) is a Django app that allows you to run Django
applications on Google App Engine, including (if you want to) using
Django's models with the App Engine Datastore as the underlying
database.
It has a Database backend that supports AppEngine's Datastore, so you can use Django's ORM. In addition to Django's default fields, a number of other field types are added in the project.
You should consider the list of limitations carefully though.

Related

Ways to run django on google app engine that uses ndb

I'm trying to shift the existing webapp2 and jinjia2 templating to Django. But the initial Django project that I wanted to shift that was also stated on Google website link has been deprecated hence I'm worried that there will be no more support in the future if I continue using it. What are the other Django project that I could use. One important criteria is that I could still use the ndb datastore with the new Django framework. I found two other alternative:
Django App Engine
and
Djangae.
May I know what are the difference between them or are there other alternatives out there?

Deploy Django project on Google App Engine

I have developed one example project in django1.4 & python 2.7, I want to deploy it on google app engine,
but how to configure my project as per App Engine we didn't get.
We have a site running on google app engine, but it is including with all html,js.
How do we configure a database on google app engine to deploy our django project?
Possibly the best option is to use Django Non-Rel. It's the only way (that I know of) to use the Django ORM (the django database interface) on Google App Engine without using Google's costly cloud SQL service. To do this, you'll need to use a customized version of Django and import several more libraries. It's a small project to get it up and running, but it's worth the effort. More information can be found on this website:
http://django-nonrel.org/
Note, that even though django-nonrel allows you to use the Django database interface, it will not allow you to use certain SQL features, such as joins. If you need joins, then your best option would be to use Google App Engine + Google Cloud SQL. Documentation for that is here.
Regarding the comments:
Yes, it can run on windows, I run it on Windows.
Also, the site allbuttonspressed.com is old and out of date, use the
one above for information.

What are the limitations of using Django nonrel with Google App Engine?

I understand that full django can be used out of the box with CloudSQL. But I'm interested in using HRD. I'd like to learn more about what percentage of django can be used with nonrel. Does middleware work? How about other features of the framework like i18n, forms, etc. Also does nonrel work with NDB?
The background here is that I've even using webapp2 and before that webapp and find them great until your project gets bigger. So for this project I'm interested to reevaluate other options.
The big limitation is that the datastore doesn't do JOINs, so anything that uses JOINS, like many-to-many relations won't work.
Any packages/middleware that uses many-to-many won't work, but others will.
For example, the sessions/auth middleware will work. But if you use permissions with auth, it won't. If you use the admin pages for auth, they use permissions, so you'll have some trouble with those too.
i8n works.
forms work.
nonrel does not work with ndb.
I don't know what you mean by "until your project gets bigger". django-nonrel won't help with the size of your app.
In my opinion there's two big reasons to use nonrel:
You're non-committal about App Engine. Nonrel potentially allows you to move to MongoDB as a backend.
You want to use django packages for "free". For example, I used tastypie for a REST API, and django-social-auth to get OAuth for FB/Twitter logins with very little effort. (On the flip side, with 1.7.0, they've addressed the REST API with endpoints)

How to migrate Django project to Google App Engine

I am looking for a guide to migrate Django project to Google App Engine and use Google's datastore. The most of the guides I found were linked to Django-Appengine using Django-nonrel (but I want to use GAE's native support).
Going through GAE getting started guide, it says:
Google App Engine supports any framework written in pure Python that speaks CGI (and any WSGI-compliant framework using a CGI adaptor), including Django, CherryPy, Pylons, web.py, and web2py. You can bundle a framework of your choosing with your application code by copying its code into your application directory.
I understand that I won't be able to use some features of Django in that case (majorly the admin feature) and would also need to restructure the models.
From other reading, I also found that latest SDK of GAE now includes Django 1.3 on Python 2.5.
I tried to put all files from my Django application to a GAE project, but couldn't get it all to work together.
Please provide some basic guide using which I may migrate my Django project to Google App Engine's code.
Thanks.
For an existing Django app, using django-nonrel is the simplest approach; it is very popular so you should be able to find help with specific errors you get quickly.
Another approach is written up in this article: http://code.google.com/appengine/articles/pure_django.html -- it goes the other way, taking an App Engine app that uses Django for dispatch, templates, and forms, but not for models, and describes how to make it run in a native Django environment. Maybe you can glean some useful hints for your situation from it.
I've used django-nonrel, which behaves pretty much like django, except that operations with JOINs will return errors. I've basically worked around this by avoiding ManyToMany fields, and essentially building that functionality manually with an intermediate table.
So far I've ran into two problems with Django-nonrel:
1. No access to ancestor queries, which can be run in a transaction. There's a pending pull request for this feature though.
2. You can't specify fields that are not indexed. This could significantly increase your write costs. I have an idea to fix this, but I haven't done so yet.
(Edit: You CAN specify fields that are not indexed, and I've verified this works well).
2 (new). Google is pushing a new database backend called ndb that does automatic caching and batching, which will not be available with django-nonrel.
If you decide not to use django-nonrel, the main differences are that Django models do not run under App Engine. You'll have to rewrite your models to inherit from App Engine's db.Model. Your forms that use Django's ModelForm will need to inherit from google.appengine.ext.db.djangoforms instead. Once you're on App Engine, you'd have to port back Django if you ever take your app somewher else.
If you already have a Django application you might want to check this out. You won't work with App Engine's datastore but Google Cloud SQL might fit your needs.

Using Beaker on Google App Engine (Django)

How do we use Beaker to implement sessions on Google App Engine? (I say Beaker because gmemsess is short-lived, and therefore not suitable). There seem to be no examples online.
We're using Django 1.1 via App Engine Helper (not app-engine-patch).
You need to specify the session type as 'ext:google', like this. You also need to edit beaker/cache.py, deleting the section that uses pkg_resources to search for plugins, as this isn't supported on App Engine.