Patrole’s primary responsibility is to ensure that your OpenStack cloud has properly configured Role-Based Access Control (RBAC). All Patrole tests cases are devoted to this responsibility. Tempest API clients and utility functions are leveraged to accomplish this goal, but such functionality is secondary to RBAC validation.
Like Tempest, Patrole not only tests expected positive paths for RBAC validation, but also – and more importantly – negative paths. While Patrole could be thought of as validating RBAC, it more importantly verifies that your OpenStack cloud is secure from the perspective of RBAC (there are many gotchas when it comes to security, not just RBAC).
Negative paths are arguably more important than positive paths when it comes to RBAC and by extension security, because it is essential that your cloud be secure from unauthorized access. For example, while it is important to verify that the admin role has access to admin-level functionality, it is of critical importance to verify that non-admin roles do not have access to such functionality.
Unlike Tempest, Patrole accomplishes negative testing implicitly – by abstracting it away in the background. Patrole dynamically determines whether a role should have access to an API depending on your cloud’s policy configuration and then confirms whether that is true or false.
These tests constitute the core mission in Patrole: to verify RBAC. These tests are mainly intended to validate RBAC, but can also unofficially be used to discover the policy-to-API mapping for an OpenStack component.
It could be argued that some of these tests could be implemented in the projects themselves, but that approach has the following shortcomings:
oslo.policy
that is
in reality passed by the deployed server to that library to determine
whether a given user is authorized to perform an API action.The Patrole framework can’t be applied to existing Tempest tests via RBAC Rule Validation Module, because:
os_admin
credentials for admin APIs and os_primary
for non-admin APIs.
This breaks for custom policy overrides.Patrole should be a separate project that specializes in RBAC tests. This was agreed upon during discussion that led to the approval of the RBAC testing framework spec, which was the genesis for Patrole.
Philosophically speaking:
Practically speaking:
RBAC tests should always use the Tempest implementation of the OpenStack API, to take advantage of Tempest’s stable library.
Each test should test a specific API endpoint and the related policy.
Each policy should be tested in isolation of one another – or at least as close to this rule as possible – to ensure proper validation of RBAC.
Each test should be able to work for positive and negative paths.
All tests should be able to be run on their own, not depending on the state created by a previous test.
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