Update to microversion 2.27

This enables the use of the OpenStack-API-Version header, in
addition to the older X-OpenStack-Nova-API-Version header.

If the client knows that it is in a version less than 2.27, it
will not send the newer header.

If the client knows that is in a version >= 2.27 if it gets a
response that does not have the expected response header (the
newer one) it will warn. If it is in an older version, it will
warn about the other one missing.

A server that is 2.27 or beyond will accept both headers and
respond with both.

Change-Id: I1f7b1ca0fe795e4ecd333de761d96fff117969c0

novaclient/__init__.py

@@ -25,4 +25,4 @@ API_MIN_VERSION = api_versions.APIVersion("2.1")
 # when client supported the max version, and bumped sequentially, otherwise
 # the client may break due to server side new version may include some
 # backward incompatible change.
-API_MAX_VERSION = api_versions.APIVersion("2.26")
+API_MAX_VERSION = api_versions.APIVersion("2.27")

novaclient/api_versions.py

@@ -29,7 +29,9 @@ if not LOG.handlers:
     LOG.addHandler(logging.StreamHandler())
 
 
-HEADER_NAME = "X-OpenStack-Nova-API-Version"
+LEGACY_HEADER_NAME = "X-OpenStack-Nova-API-Version"
+HEADER_NAME = "OpenStack-API-Version"
+SERVICE_TYPE = "compute"
 # key is a deprecated version and value is an alternative version.
 DEPRECATED_VERSIONS = {"1.1": "2"}
 
@@ -317,19 +319,25 @@ def discover_version(client, requested_version):
 
 
 def update_headers(headers, api_version):
-    """Set 'X-OpenStack-Nova-API-Version' header if api_version is not null"""
+    """Set microversion headers if api_version is not null"""
 
-    if not api_version.is_null() and api_version.ver_minor != 0:
+    if not api_version.is_null():
-        headers[HEADER_NAME] = api_version.get_string()
+        version_string = api_version.get_string()
+        if api_version.ver_minor != 0:
+            headers[LEGACY_HEADER_NAME] = version_string
+        if api_version.ver_minor >= 27:
+            headers[HEADER_NAME] = '%s %s' % (SERVICE_TYPE, version_string)
 
 
 def check_headers(response, api_version):
-    """Checks that 'X-OpenStack-Nova-API-Version' header in response."""
+    """Checks that microversion header is in response."""
-    if api_version.ver_minor > 0 and HEADER_NAME not in response.headers:
+    if api_version.ver_minor > 0:
-        LOG.warning(_LW(
+        if (api_version.ver_minor < 27
-            "Your request was processed by a Nova API which does not support "
+                and LEGACY_HEADER_NAME not in response.headers):
-            "microversions (%s header is missing from response). "
+            _warn_missing_microversion_header(LEGACY_HEADER_NAME)
-            "Warning: Response may be incorrect."), HEADER_NAME)
+        elif (api_version.ver_minor >= 27
+                and HEADER_NAME not in response.headers):
+            _warn_missing_microversion_header(HEADER_NAME)
 
 
 def add_substitution(versioned_method):
@@ -378,3 +386,11 @@ def wraps(start_version, end_version=None):
         return substitution
 
     return decor
+
+
+def _warn_missing_microversion_header(header_name):
+    """Log a warning about missing microversion response header."""
+    LOG.warning(_LW(
+        "Your request was processed by a Nova API which does not support "
+        "microversions (%s header is missing from response). "
+        "Warning: Response may be incorrect."), header_name)

novaclient/tests/unit/test_api_versions.py

@@ -144,6 +144,18 @@ class UpdateHeadersTestCase(utils.TestCase):
             {"X-OpenStack-Nova-API-Version": api_version.get_string()},
             headers)
 
+    def test_api_version_is_gte_27(self):
+        api_version = api_versions.APIVersion("2.27")
+        headers = {}
+        api_versions.update_headers(headers, api_version)
+        self.assertIn('X-OpenStack-Nova-API-Version', headers)
+        self.assertIn('OpenStack-API-Version', headers)
+        self.assertEqual(api_version.get_string(),
+                         headers['X-OpenStack-Nova-API-Version'])
+        self.assertEqual('%s %s' % (api_versions.SERVICE_TYPE,
+                                    api_version.get_string()),
+                         headers['OpenStack-API-Version'])
+
 
 class CheckHeadersTestCase(utils.TestCase):
     def setUp(self):
@@ -152,8 +164,9 @@ class CheckHeadersTestCase(utils.TestCase):
         self.mock_log = mock_log_patch.start()
         self.addCleanup(mock_log_patch.stop)
 
-    def test_microversion_is_specified(self):
+    def test_legacy_microversion_is_specified(self):
-        response = mock.MagicMock(headers={api_versions.HEADER_NAME: ""})
+        response = mock.MagicMock(
+            headers={api_versions.LEGACY_HEADER_NAME: ""})
         api_versions.check_headers(response, api_versions.APIVersion("2.2"))
         self.assertFalse(self.mock_log.warning.called)
 
@@ -161,8 +174,19 @@ class CheckHeadersTestCase(utils.TestCase):
         api_versions.check_headers(response, api_versions.APIVersion("2.2"))
         self.assertTrue(self.mock_log.warning.called)
 
+    def test_generic_microversion_is_specified(self):
+        response = mock.MagicMock(
+            headers={api_versions.HEADER_NAME: ""})
+        api_versions.check_headers(response, api_versions.APIVersion("2.27"))
+        self.assertFalse(self.mock_log.warning.called)
+
+        response = mock.MagicMock(headers={})
+        api_versions.check_headers(response, api_versions.APIVersion("2.27"))
+        self.assertTrue(self.mock_log.warning.called)
+
     def test_microversion_is_not_specified(self):
-        response = mock.MagicMock(headers={api_versions.HEADER_NAME: ""})
+        response = mock.MagicMock(
+            headers={api_versions.LEGACY_HEADER_NAME: ""})
         api_versions.check_headers(response, api_versions.APIVersion("2.2"))
         self.assertFalse(self.mock_log.warning.called)
 

novaclient/tests/unit/v2/test_shell.py

@@ -2776,6 +2776,9 @@ class ShellTest(utils.TestCase):
                  #   new microversion, just an additional checks. See
                  #   https://review.openstack.org/#/c/233076/ for more details)
             20,  # doesn't require any changes in novaclient
+            27,  # NOTE(cdent): 27 adds support for updated microversion
+                 #   headers, and is tested in test_api_versions, but is
+                 #   not explicitly tested via wraps and _SUBSTITUTIONS.
         ])
         versions_supported = set(range(0,
                                  novaclient.API_MAX_VERSION.ver_minor + 1))