Fixes #1556 adding Django env

[MFlyer]

#1556 :

To @schakrava : here my PR, hope had it right way (actually Pincardmanager working fine!)

Ready to review
Mirko

[schakrava]

Hi @MFlyer this pr made me realize there's a design flaw in the pincard manager implementation. Let me explain. data-collector is a separate service, and we could use django-ORM to directly update models in the database. You are doing this now, but it creates new postgresql connections and in my experience leads to bad behaviour with resource starvation and becomes hard to debug.

The preferred way is to expose CRUD operations on Pincard model via REST API just like we do it on other resource like Disk, Pool, User etc.. Then, data-collector would use APIWrapper.api_call() to create, update and delete Pincard models. Routing it this way is better than playing hard and fast with ORM. We do this in data-collector already for other operations like updating rockons metadata etc..

Using ORM directly from data-collector just for reads is usually OK, something to keep in mind as well if you just want to read something from db and there's no API...

[MFlyer]

Thanks @schakrava ,
will work on this asap (asap = before you close for 3.8.16 ;) )

EDIT to @schakrava about 3.8.16:
what are your plans with 3.8.16?
Let me explain: actually at work it's a "Keep calm and don't kill anyone" period at least till weekend, so I can code new Pincard view etc these days, but probably this would mean have it in the "wrong" way.
If we're having 3.8.16 soon, considering PincardManager hasn't daily running tasks (users supposed to create a pincard one time and to recover password only in case of emergency) like dashboard widgets, if you agree we can have it solved with this PR to grant a working release and queue CRUD way to 3.8.17 cycle.
Let me know and obviously I'll anyway try to have it asap :)

[schakrava]

Hi @MFlyer . Please don't rush on the proper implementation. Do it thoroughly like you normally do. I am planning to close out 3.8.16 soon as I and @priyaganti finish testing and fix any important bugs we encounter in the process. So no clear estimate, but it would be great to get the release out within a week.

I am totally fine with merging this PR for 3.8.16 and replacing it with improvements after that. Sound good?

[MFlyer]

Thanks @schakrava ,
thinking about Pincard via APIWrapper not sure still deciding if have it with CBV of FBV (Pincard management is alike Logs Manager, more running of custom functions then models interactions)
M.

[schakrava]

Looks like this change is required regardless of our design consideration, because of a django refactor since 1.7. check this out: https://docs.djangoproject.com/en/1.10/releases/1.7/#app-loading-refactor