Add role assignment test coverage for system members

This commit adds role assignment test coverage for users who have the
member role assigned on the system.

Subsequent patches will:

  - add test coverage for system admins
  - add functionality for domain readers
  - add functionality for domain members
  - add functionality for domain admins
  - add functionality for project readers
  - add functionality for project members
  - add functionality for project admins
  - remove the obsolete policies from policy.v3cloudsample.json

Change-Id: Ie5333bf61a704d4167004457ec1d9b19b4bb01e8
Partial-Bug: 1750673
Partial-Bug: 1816833

keystone/tests/unit/protection/v3/test_assignment.py

@@ -689,3 +689,45 @@ class SystemReaderTests(base_classes.TestCaseWithBootstrap,
             r = c.post('/v3/auth/tokens', json=auth)
             self.token_id = r.headers['X-Subject-Token']
             self.headers = {'X-Auth-Token': self.token_id}
+
+
+class SystemMemberTests(base_classes.TestCaseWithBootstrap,
+                        common_auth.AuthTestMixin,
+                        _AssignmentTestUtilities,
+                        _SystemUserTests):
+
+    def setUp(self):
+        super(SystemMemberTests, self).setUp()
+        self.loadapp()
+        self.useFixture(ksfixtures.Policy(self.config_fixture))
+        self.config_fixture.config(group='oslo_policy', enforce_scope=True)
+
+        system_member = unit.new_user_ref(
+            domain_id=CONF.identity.default_domain_id
+        )
+        self.user_id = PROVIDERS.identity_api.create_user(
+            system_member
+        )['id']
+        PROVIDERS.assignment_api.create_system_grant_for_user(
+            self.user_id, self.bootstrapper.member_role_id
+        )
+        self.expected = [
+            # assignment of the user running the test case
+            {
+                'user_id': self.user_id,
+                'system': 'all',
+                'role_id': self.bootstrapper.member_role_id
+            }
+        ]
+
+        auth = self.build_authentication_request(
+            user_id=self.user_id, password=system_member['password'],
+            system=True
+        )
+
+        # Grab a token using the persona we're testing and prepare headers
+        # for requests we'll be making in the tests.
+        with self.test_client() as c:
+            r = c.post('/v3/auth/tokens', json=auth)
+            self.token_id = r.headers['X-Subject-Token']
+            self.headers = {'X-Auth-Token': self.token_id}