Get List of Roles for App

[nelsonic]

In order to allow custom roles for any App that uses Auth, we need a way of getting the list of roles that are relevant to that App once during application startup. The list should be cached in memory to speed up in-app role checking. Such that a call to RBAC.has_role(person, "hotel_guest") dwyl/rbac#2 should take less than a microsecond (zero network latency).

Todo

• Roles should be linked to an App: Create "App" Schema/CRUD then Link API Keys and Roles #95 > Add app_id to roles schema #108 ✅
• use AUTH_API_KEY to request the list of Roles & Permissions relevant to a given App
  • Response should be a JSON Array of Objects similar to default_roles.json which should be decoded/parsed as a List of Maps in Elixir using Jason.decode/2 (which means we will need to add it as a dependency).
• cache the List of Roles in memory to avoid any further HTTP requests > PR: Get and Cache List of Roles + Helper Functions: has_role?/2 rbac#7
• Refresh the list when the app is Re-booted.

[nelsonic]

Dummy request already working: http://localhost:4000/approles/:client_id

Now I just need to work on restricting to the roles of the app via :client_id ⏳

[nelsonic]

I've naively tried doing the caching of the approles list in the auth_plug and was immediately reminded (obvs in retrospect) that any function put in a plug runs on each/every request. again, obvs. So instead, we need to run our GET /approles/:client_id in a config.exs or "startup" script.

Reading: https://moosecode.nl/blog/where-do-i-put-startup-code-in-elixir

[nelsonic]

OK. We have a get_approles/2 function working in:
https://github.com/dwyl/rbac/blob/e05a58a7c70dcad9bd0350d516d1e01ea7c2d452/lib/rbac.ex#L41-L49

Next we need to cache the list of roles in ETS, going to borrow some code from:
https://github.com/club-soda/club-soda-guide/search?q=ets&unscoped_q=ets

Tomorrow. 😴

[nelsonic]

Cache working:
https://github.com/dwyl/rbac/blob/7dcab4458da60fa2371cad05abc3d38278d70db3/lib/rbac.ex#L87-L97