Reading
- Watch Solving bizarre authorization requirements with Rails
- Read the Consul README Show archive.org snapshot
- Read the assignable_values README Show archive.org snapshot
Understand how Consul and assignable_values can be used to implement arbitrary authorization systems.
Exercise: Read code
- In Cards, users can be given deck-specific read/write access. Play around in the cards UI to see that functionality.
- How does the application decide whether or not to render the "Edit card" button?
- See if you can follow the code from the view that renders the button back to the code that is responsible for granting or denying access.
Exercise: Role-based authorization
Use Consul and assignable_values to implement role-based authorization in MovieDB:
- Add a
User#role
field to MovieDB. The field can be switched betweenreader
/writer
/admin
values. - A reader is allowed to view all movies. A reader is not allowed to create a new movie or edit or delete an existing movie.
- A writer is like a reader, but is also allowed to create new movies. A writer can edit and delete the movies she created herself, but not movies created by other users.
- An admin is allowed to create, view and edit and delete all movies.
- The admin may change the author of any movie by picking a user option from a
<select>
in the movie form. However, non-admins should only see their own user as an option in the same<select>
.
Remember to add tests for your authorization code.
Tip
If you have existing dropdowns that accept a restrict list of values (e.g. genre), you can simplify their implementation with assignable_values Show archive.org snapshot .
Discussion
Discuss with your mentor:
- We don't want to duplicate our integration tests for every screen and user role. Why?
- Where to put authorization scenarios? In an
authorization.feature
or under each resource folder, like the other scenarios. - If one role has, for a given resource, more permission than another role, should we have separate controllers and views?
Posted by Henning Koch to makandra Curriculum (2015-08-05 11:58)