Traversal-like resources with Cornice

Question

I want to make RESTFul traversal-like resources with Pyramid and Cornice.

e.g.

  /customers/{xxx}/invoices
  /customers/{xxx}/invoices/{yyy}
  /customers/{xxx}/invoices/{yyy}/pdf

... where at {xxx} path all the available customers for the user would be listed and if there are any customers for whom the user do not have a permission for the access is blocked.

I'd like to do this in traversal-like manner, so that I need to write access checks only once in well defined manner.

The URL format itself is not relevant; it can be path or query parameter. I just want to make sure the permission check is the same for all endpoints.

I am looking for methods to approach this problem.