Running a single version of my Django app but with two databases: one for dev and one for prod

[jim_rain]

Hi, 

I'm developing a Django app, it's hosted on an EC2 instance so I'm using wsgi, even in development. I would like to create a production and a development version where really the only things that are different are the two databases. I want the code to be the same on both. I figured I could just have two settings files and two wsgi.py files so it's set up like this:

wsgi_prod.py:

import os

from django.core.wsgi import get_wsgi_application

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "canzare.settings.production")

application = get_wsgi_application()

wsgi_dev.py:

import os

from django.core.wsgi import get_wsgi_application

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "canzare.settings.development")

application = get_wsgi_application()

Then in my httpd.conf I have these lines:

WSGIScriptAlias /dev /home/canzare/work_area/canzare/canzare/wsgi_dev.py

WSGIScriptAlias / /home/canzare/work_area/canzare/canzare/wsgi_prod.py

The only real difference in the settings.py files is that they point to two different databases in mysql. 

This sort of works, I can access the production site with <mysite>/ and I can access the development site with <mysite>/dev/

But then everything falls apart. The admin site on both seems to be broken. It looks ok but if I try to perform any actions it tries to make me re-login. 

Also (and this may be the root of the other problem) I don't think migration works correctly. I can migrate to one instance but not the other. 

Has anybody come across something like this before and/or and I'm going about this completely wrong and is there a better way?

Thanks. 

Jim

[heriberto ochoa]

your can use routers, or the directive DATABASE in separate files development and production with respective configuration

[Jason]

to be honest, this seems like much more effort than its worth.

[Michal Petrucha]

On Mon, Sep 24, 2018 at 03:18:46PM -0700, jim_rain wrote:
> Hi,
>
> I'm developing a Django app, it's hosted on an EC2 instance so I'm using
> wsgi, even in development. I would like to create a production and a
> development version where really the only things that are different are the
> two databases. I want the code to be the same on both. I figured I could
> just have two settings files and two wsgi.py files so it's set up like this:
>
> wsgi_prod.py:
>

> *import os*
>
> *from django.core.wsgi import get_wsgi_application*
>
> *os.environ.setdefault("DJANGO_SETTINGS_MODULE",
> "canzare.settings.production")*
>
> *application = get_wsgi_application()*
>
>
> wsgi_dev.py:
>
>
> *import os*
>
> *from django.core.wsgi import get_wsgi_application*
>
> *os.environ.setdefault("DJANGO_SETTINGS_MODULE",
> "canzare.settings.development")*
>
> *application = get_wsgi_application()*

>
>
> Then in my httpd.conf I have these lines:
>
>

> *WSGIScriptAlias /dev /home/canzare/work_area/canzare/canzare/wsgi_dev.py*
>
> *WSGIScriptAlias / /home/canzare/work_area/canzare/canzare/wsgi_prod.py*

>
>
> The only real difference in the settings.py files is that they point to two
> different databases in mysql.
>
>
> This sort of works, I can access the production site with <mysite>/ and I
> can access the development site with <mysite>/dev/
>
>
> But then everything falls apart. The admin site on both seems to be broken.
> It looks ok but if I try to perform any actions it tries to make me
> re-login.
>
>
> Also (and this may be the root of the other problem) I don't think
> migration works correctly. I can migrate to one instance but not the other.
>
>
> Has anybody come across something like this before and/or and I'm going
> about this completely wrong and is there a better way?

First, regarding management commands, of course, if you have different
WSGI applications using different settings, you need to match your
management commands to those as well. So if you want to migrate the
production database, you need to run the migrate management command
with DJANGO_SETTINGS_MODULE pointing to the production settings, and
likewise for the development environment.

Second, just using different databases might not be enough, at the
very least, another obvious thing you'd probably want to isolate is
media storage, not to mention caches, and what have you.

Third, the issue with cookies is because you presumably use the same
cookie name for the session cookie for both deployments, so they
overwrite each others' session IDs. While you can fix this by setting
a custom name for the session cookie in one of the settings modules,
you're likely to encounter such conflicts for any other cookies that
you might use, too.

Oh, and it's likely that a lot of links from your deployment sitting
at the /dev/ prefix will point to URLs sitting in the production
deployment, unless you're extra careful with making sure that all
links include the script prefix.

All in all, your approach seems like it's more trouble than it's
worth, and you'll make your life a lot easier if you just make two
separate deployments sitting on separate domains. (A relatively common
approach is to use a “dev.” or “staging.” or “beta.” subdomain of your
main domain for the dev/testing/staging environment.)

Good luck,

Michal