Add required_platform@openstack validator

With Rally > 0.12 we need to handle checks for admin/users credentials
manually.

Depends-On: I546bbd9b0e35abb30195b0f8c98756a9cce10107
Change-Id: Icaafd9d038fb789b9f9e5ed63cc220d301d9b48e

rally_openstack/validators.py

@@ -26,6 +26,7 @@ from rally import exceptions
 from rally.plugins.common import validators
 from rally.task import types
 
+import rally_openstack
 from rally_openstack import consts
 from rally_openstack.contexts.keystone import roles
 from rally_openstack.contexts.nova import flavors as flavors_ctx
@@ -35,6 +36,46 @@ from rally_openstack import types as openstack_types
 LOG = logging.getLogger(__name__)
 
 
+class RequiredOpenStackValidator(validation.RequiredPlatformValidator):
+    def __init__(self, admin=False, users=False):
+        """Validates credentials for OpenStack platform.
+
+        This allows us to create 3 kind of tests cases:
+        1) requires platform with admin
+        2) requires platform with admin + users
+        3) requires platform with users
+
+        :param admin: requires admin credential
+        :param users: requires user credentials
+        """
+        super(RequiredOpenStackValidator, self).__init__(platform="openstack")
+        self.admin = admin
+        self.users = users
+
+    def validate(self, context, config, plugin_cls, plugin_cfg):
+        if not (self.admin or self.users):
+            self.fail("You should specify admin=True or users=True or both.")
+
+        context = context["platforms"].get(self.platform, {})
+
+        if self.admin and context.get("admin") is None:
+            self.fail("No admin credentials for openstack")
+        if self.users and len(context.get("users", ())) == 0:
+            if context.get("admin") is None:
+                self.fail("No user credentials for openstack")
+            else:
+                # NOTE(andreykurilin): It is a case when the plugin requires
+                #   'users' for launching, but there are no specified users in
+                #   deployment. Let's assume that 'users' context can create
+                #   them via admin user and do not fail."
+                pass
+
+
+if rally_openstack.__rally_version__ >= (0, 13):
+    RequiredOpenStackValidator = validation.configure(
+        "required_platform", platform="openstack")(RequiredOpenStackValidator)
+
+
 def with_roles_ctx():
     """Add roles to users for validate
 

tests/unit/test_validators.py

@@ -66,6 +66,49 @@ def test_with_roles_ctx(mock_role_generator):
     mock_role_generator().setup.assert_called_once_with()
 
 
+class RequiredOpenStackValidatorTestCase(test.TestCase):
+    def validate(self):
+        validator = validators.RequiredOpenStackValidator(admin=True)
+        validator.validate(
+            {"platforms": {"openstack": {"admin": "foo"}}}, {}, None, None)
+
+        validator = validators.RequiredOpenStackValidator(users=True)
+        validator.validate(
+            {"platforms": {"openstack": {"admin": "foo"}}}, {}, None, None)
+
+        validator = validators.RequiredOpenStackValidator(users=True)
+        validator.validate(
+            {"platforms": {"openstack": {"users": ["foo"]}}}, {}, None, None)
+
+    def test_validate_failed(self):
+        # case #1: wrong configuration of validator
+        validator = validators.RequiredOpenStackValidator()
+        e = self.assertRaises(
+            validators.validation.ValidationError,
+            validator.validate, {}, {}, None, None)
+        self.assertEqual(
+            "You should specify admin=True or users=True or both.",
+            e.message)
+
+        # case #2: admin is not present
+        validator = validators.RequiredOpenStackValidator(admin=True)
+        e = self.assertRaises(
+            validators.validation.ValidationError,
+            validator.validate,
+            {"platforms": {"openstack": {}}}, {}, None, None)
+        self.assertEqual("No admin credentials for openstack",
+                         e.message)
+
+        # case #3: users are not present
+        validator = validators.RequiredOpenStackValidator(users=True)
+        e = self.assertRaises(
+            validators.validation.ValidationError,
+            validator.validate,
+            {"platforms": {"openstack": {}}}, {}, None, None)
+        self.assertEqual("No user credentials for openstack",
+                         e.message)
+
+
 @ddt.ddt
 class ImageExistsValidatorTestCase(test.TestCase):
 

tests/unit/test_workarounds.py

@@ -30,9 +30,15 @@ class WorkaroundTestCase(test.TestCase):
         ([0, 12], [
             "'rally_openstack.__init__' module contains a hack for loading "
             "configuration options.",
+
             "'rally_openstack.types' module contains a compatibility layer for"
             " an old interface of ResourceTypes."]
-         )
+         ),
+        ([0, 13], [
+            "'rally_openstack.validators' module has a check to do not "
+            "register 'required_platforms@openstack' validator for old Rally "
+            "releases."
+        ])
     ]
 
     def get_min_required_version(self):