rails 4 with activerecord, devise, cancan and rolify for authentication/authorisation

Rails is a great tool and just recently I discovered the full potential of it, although I am still not using to the full.

How do all these gems work together - why rolify?

Devise does the authentication and uses a table named 'User' e.g. and gives the found user access to the specific part of your site.
Now cancan joines the game and since you will have marked models or part of the site with roles, it checks if a user is allowed: authorised.
Normally this is done through another column in the users table (you had to do yourself prior), but then you can assign one role to one user.

Rolify uses another approach when assigning roles, it creates a joint table connecting the User model to the Role model. That "could" mean you can assign several roles to a user, e.g. moderate and also be a mini admin.

Rolify bug:

The migration file had no file extension, with this missing "rb" I chased after the error "could not find Role table".

My Problems with all of them

Active Admin can be installed using Devis, there are just some problems that had me going for a while:

• the docs are old, so look a the github docs, NO OTHER PAGE!!!
  and I am a little bit pissed because there is a official tutorial that sucks
• it clashed with foundation, so delete the line in application.css:
  require tree
• then go to config/environments/production.rb and change the precompile line to:
  config.assets.precompile += %w(active_admin.css.scss )
  config.assets.precompile += %w(active_admin.js.coffee)
• the mirgration file of active admin using devise was almost similar to the one devise already ran, so there were some unnecessary errors

Test you settings with this command, it may show some other stuff with foundation or bootstrap or whatever is up. This is important because in case you deploy with capistrano that command can cause a failed deployment which then is harder do debug:

RAILS_ENV=production bundle exec rake assets:precompile --trace 

Best practise

Use git and create a branch for this. It is very complex to get all of these to work and it is easy to mess it all up. After all of this is working properly and ActiveAdmin is initialised to use cancan (config/initializers/active_admin.rb) and you login to /admin by your normal log screen/page, then you may do a merge and be happy.

I had to do a hard reset because I followed the wrong (official) page and everything was set up half.