Support for both microversion headers

In this change the new OpenStack-API-Version headers is allowed,
but not required, for requesting a microversion.

Both headers are accepted in the request and both headers are sent in
the response (both the header and its value, and the addition to the Vary
header).

Many tests which explicitly use a microversion header have been
updated to use both. This change is not 100% as most of the tests
are testing the handling of the value of the header, not which
header is involved.

Partially-Implements: blueprint modern-microversions
Change-Id: I68da13b5ba0c2f3357523e765a5b9db81899daf1

1 files changed, 13 insertions, 6 deletions

diff --git a/nova/api/openstack/wsgi.py b/nova/api/openstack/wsgi.py
index eddf4cbf19..a9e6fe850a 100644
--- a/nova/api/openstack/wsgi.py
+++ b/nova/api/openstack/wsgi.py
@@ -71,9 +71,10 @@ DEFAULT_API_VERSION = "2.1"
 # name of attribute to keep version method information
 VER_METHOD_ATTR = 'versioned_methods'
 
-# Name of header used by clients to request a specific version
+# Names of headers used by clients to request a specific version
 # of the REST API
-API_VERSION_REQUEST_HEADER = 'X-OpenStack-Nova-API-Version'
+API_VERSION_REQUEST_HEADER = 'OpenStack-API-Version'
+LEGACY_API_VERSION_REQUEST_HEADER = 'X-OpenStack-Nova-API-Version'
 
 
 ENV_LEGACY_V2 = 'openstack.legacy_v2'
@@ -230,7 +231,7 @@ class Request(wsgi.Request):
         """Set API version request based on the request header information."""
         hdr_string = microversion_parse.get_version(
             self.headers, service_type='compute',
-            legacy_headers=[API_VERSION_REQUEST_HEADER])
+            legacy_headers=[LEGACY_API_VERSION_REQUEST_HEADER])
 
         if hdr_string is None:
             self.api_version_request = api_version.APIVersionRequest(
@@ -767,8 +768,11 @@ class Resource(wsgi.Application):
 
             if not request.api_version_request.is_null():
                 response.headers[API_VERSION_REQUEST_HEADER] = \
+                    'compute ' + request.api_version_request.get_string()
+                response.headers[LEGACY_API_VERSION_REQUEST_HEADER] = \
                     request.api_version_request.get_string()
-                response.headers['Vary'] = API_VERSION_REQUEST_HEADER
+                response.headers.add('Vary', API_VERSION_REQUEST_HEADER)
+                response.headers.add('Vary', LEGACY_API_VERSION_REQUEST_HEADER)
 
         return response
 
@@ -1121,9 +1125,12 @@ class Fault(webob.exc.HTTPException):
 
         if not req.api_version_request.is_null():
             self.wrapped_exc.headers[API_VERSION_REQUEST_HEADER] = \
+                'compute ' + req.api_version_request.get_string()
+            self.wrapped_exc.headers[LEGACY_API_VERSION_REQUEST_HEADER] = \
                 req.api_version_request.get_string()
-            self.wrapped_exc.headers['Vary'] = \
-              API_VERSION_REQUEST_HEADER
+            self.wrapped_exc.headers.add('Vary', API_VERSION_REQUEST_HEADER)
+            self.wrapped_exc.headers.add('Vary',
+                                         LEGACY_API_VERSION_REQUEST_HEADER)
 
         self.wrapped_exc.content_type = 'application/json'
         self.wrapped_exc.charset = 'UTF-8'