I have been working on something similar for some time now, and so far I haven't encountered any problems. I have a single web2py app and a single PostgreSQL database. In db.py I defined a 'company' table and added a company_id field to all the other tables (writable and readable set to False). (Because I ran into trouble extending functionality, I have planned to alter the data model in a next iteration. Define a 'party' table and change all the company_id references to party_id and add a 'organisation' table and 'people' table.)
In the web2py app I have, amongst others, a user cms and an admin cms controller. The user cms completely depends on the company_id field I added to the auth_user table. I my case I have five groups: root, plan1, plan2, plan3 and plan4, where the plans are packages of functions. I coded a custom registration function, in which I link users to groups in the auth_membership table. The admin cms can be accessed by users with root membership. They retrieve the company of which they want to administer the data and the company_id is set in session.company_id. I hope this gives you an idea of one possible solution. Kind regards, Annet.
