Add microversion headers to root ('/') endpoint

Adds microversion headers to the root endpoint so the '/' and '/v1'
endpoints consistently include microversion headers.

Closes-Bug: #2079023
Change-Id: Iea78b33e04e256c1139dd46a25f6d6a2be8e1ccc

ironic/api/controllers/root.py

@@ -38,6 +38,7 @@ class RootController(object):
 
     @method.expose()
     def index(self, *args):
+        V1.add_version_attributes()
         if args:
             pecan.abort(404)
         return root()
@@ -49,6 +50,7 @@ class RootController(object):
         It redirects the request to the default version of the ironic API
         if the version number is not specified in the url.
         """
+        V1.add_version_attributes()
 
         # support paths which are missing the first version element
         if primary_key and primary_key != version.ID_VERSION1:

ironic/api/controllers/v1/__init__.py

@@ -141,8 +141,7 @@ class Controller(object):
         # NOTE: The reason why v1() it's being called for every
         #       request is because we need to get the host url from
         #       the request object to make the links.
-        self._add_version_attributes()
+        if api.request.method not in ('GET', 'HEAD'):
-        if api.request.method != "GET":
             pecan.abort(http_client.METHOD_NOT_ALLOWED)
 
         return v1()
@@ -169,7 +168,7 @@ class Controller(object):
                  'max': versions.max_version_string()},
                 headers=headers)
 
-    def _add_version_attributes(self):
+    def add_version_attributes(self):
         v = base.Version(api.request.headers, versions.min_version_string(),
                          versions.max_version_string())
 
@@ -186,7 +185,6 @@ class Controller(object):
 
     @pecan.expose()
     def _lookup(self, primary_key, *remainder):
-        self._add_version_attributes()
 
         controller = self._subcontroller_map.get(primary_key)
         if not controller:

ironic/tests/unit/api/controllers/v1/test_root.py

@@ -29,6 +29,28 @@ class TestV1Routing(api_base.BaseApiTest):
                                                     mock.ANY,
                                                     mock.ANY)
 
+    def test_microversion_headers(self):
+        # Check root endpoint
+        response = self.app.head('/')
+        self.assertEqual(200, response.status_int)
+        self.assertIn('X-OpenStack-Ironic-API-Minimum-Version',
+                      response.headers)
+        self.assertIn('X-OpenStack-Ironic-API-Maximum-Version',
+                      response.headers)
+
+        self._check_version.reset_mock()
+
+        # Check v1 endpoint
+        response = self.app.head('/v1')
+        self.assertEqual(200, response.status_int)
+        self.assertIn('X-OpenStack-Ironic-API-Minimum-Version',
+                      response.headers)
+        self.assertIn('X-OpenStack-Ironic-API-Maximum-Version',
+                      response.headers)
+
+        # -check_version should be called only once
+        self.assertEqual(1, self._check_version.call_count)
+
     def test_min_version(self):
         response = self.get_json(
             '/',

releasenotes/notes/add-microversion-headers-to-root-endpoint-199cb910a7aa53f9.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Adds microversion headers to the root ('/') endpoint.