Allow api_version_request.matches to accept a string or None

According to the Manila devref you should be able to use the following
pattern:

if req_version.matches("2.1", "2.5"):
    ....stuff....
elif req_version.matches("2.6", "2.10"):
    ....other stuff....
elif req_version > api_version_request.APIVersionRequest("2.10"):
    ....more stuff.....

However, the api_version_request.matches() function will not accept a
string, it requires an api_version_request object.

Fix this to accept a string, as well as None for object.

Change-Id: Ic2faaaa7696cc7a647679cbb7a8600b30c3d66d7
Closes-Bug: 1550337

manila/api/openstack/api_version_request.py

@@ -15,6 +15,7 @@
 #    under the License.
 
 import re
+import six
 
 from manila.api.openstack import versioned_method
 from manila import exception
@@ -223,11 +224,21 @@ class APIVersionRequest(utils.ComparableMixin):
         # looking for equality.
         if not self.experimental and experimental:
             return False
-        if max_version.is_null() and min_version.is_null():
+
+        if isinstance(min_version, six.string_types):
+            min_version = APIVersionRequest(version_string=min_version)
+        if isinstance(max_version, six.string_types):
+            max_version = APIVersionRequest(version_string=max_version)
+
+        if not (min_version or max_version):
             return True
-        elif max_version.is_null():
+        elif (min_version and max_version and
+              max_version.is_null() and min_version.is_null()):
+            return True
+
+        elif not max_version or max_version.is_null():
             return min_version <= self
-        elif min_version.is_null():
+        elif not min_version or min_version.is_null():
             return self <= max_version
         else:
             return min_version <= self <= max_version

manila/tests/api/test_versions.py

@@ -16,6 +16,7 @@
 import ddt
 import mock
 from oslo_serialization import jsonutils
+from oslo_utils import encodeutils
 
 from manila.api.openstack import api_version_request
 from manila.api.openstack import wsgi
@@ -154,6 +155,110 @@ class VersionsControllerTestCase(test.TestCase):
         self.assertEqual('3.0', response.headers[version_header_name])
         self.assertEqual(version_header_name, response.headers['Vary'])
 
+    @ddt.data(['2.5', 200], ['2.55', 404])
+    @ddt.unpack
+    def test_req_version_matches(self, version, HTTP_ret):
+        version_request = api_version_request.APIVersionRequest(version)
+        self.mock_object(api_version_request,
+                         'max_api_version',
+                         mock.Mock(return_value=version_request))
+
+        class Controller(wsgi.Controller):
+
+            @wsgi.Controller.api_version('2.0', '2.6')
+            def index(self, req):
+                return 'off'
+
+        req = fakes.HTTPRequest.blank('/tests', base_url='http://localhost/v2')
+        req.headers = {version_header_name: version}
+        app = fakes.TestRouter(Controller())
+
+        response = req.get_response(app)
+
+        if HTTP_ret == 200:
+            self.assertEqual(b'off', response.body)
+        elif HTTP_ret == 404:
+            self.assertNotEqual(b'off', response.body)
+        self.assertEqual(HTTP_ret, response.status_int)
+
+    @ddt.data(['2.5', 'older'], ['2.37', 'newer'])
+    @ddt.unpack
+    def test_req_version_matches_with_if(self, version, ret_val):
+        version_request = api_version_request.APIVersionRequest(version)
+        self.mock_object(api_version_request,
+                         'max_api_version',
+                         mock.Mock(return_value=version_request))
+
+        class Controller(wsgi.Controller):
+
+            def index(self, req):
+                req_version = req.api_version_request
+                if req_version.matches('2.1', '2.8'):
+                    return 'older'
+                if req_version.matches('2.9', '2.88'):
+                    return 'newer'
+
+        req = fakes.HTTPRequest.blank('/tests', base_url='http://localhost/v2')
+        req.headers = {version_header_name: version}
+        app = fakes.TestRouter(Controller())
+
+        response = req.get_response(app)
+
+        resp = encodeutils.safe_decode(response.body, incoming='utf-8')
+        self.assertEqual(ret_val, resp)
+        self.assertEqual(200, response.status_int)
+
+    @ddt.data(['2.5', 'older'], ['2.37', 'newer'])
+    @ddt.unpack
+    def test_req_version_matches_with_None(self, version, ret_val):
+        version_request = api_version_request.APIVersionRequest(version)
+        self.mock_object(api_version_request,
+                         'max_api_version',
+                         mock.Mock(return_value=version_request))
+
+        class Controller(wsgi.Controller):
+
+            def index(self, req):
+                req_version = req.api_version_request
+                if req_version.matches(None, '2.8'):
+                    return 'older'
+                if req_version.matches('2.9', None):
+                    return 'newer'
+
+        req = fakes.HTTPRequest.blank('/tests', base_url='http://localhost/v2')
+        req.headers = {version_header_name: version}
+        app = fakes.TestRouter(Controller())
+
+        response = req.get_response(app)
+
+        resp = encodeutils.safe_decode(response.body, incoming='utf-8')
+        self.assertEqual(ret_val, resp)
+        self.assertEqual(200, response.status_int)
+
+    def test_req_version_matches_with_None_None(self):
+        version_request = api_version_request.APIVersionRequest('2.39')
+        self.mock_object(api_version_request,
+                         'max_api_version',
+                         mock.Mock(return_value=version_request))
+
+        class Controller(wsgi.Controller):
+
+            def index(self, req):
+                req_version = req.api_version_request
+                # This case is artificial, and will return True
+                if req_version.matches(None, None):
+                    return "Pass"
+
+        req = fakes.HTTPRequest.blank('/tests', base_url='http://localhost/v2')
+        req.headers = {version_header_name: '2.39'}
+        app = fakes.TestRouter(Controller())
+
+        response = req.get_response(app)
+
+        resp = encodeutils.safe_decode(response.body, incoming='utf-8')
+        self.assertEqual("Pass", resp)
+        self.assertEqual(200, response.status_int)
+
 
 @ddt.ddt
 class ExperimentalAPITestCase(test.TestCase):