From 3712dccfdb7ee30243e4efc09fcad1c3197bdb51 Mon Sep 17 00:00:00 2001
From: Brian Rosmaita <rosmaita.fossdev@gmail.com>
Date: Fri, 9 Feb 2018 17:12:31 -0500
Subject: [PATCH] Use configured value for import-methods header

In Image API v2.6, the image-create response returns an
'OpenStack-image-import-methods' header containing a list of
methods available in that cloud.  This patch populates that
list from the enabled_import_methods configuration setting.
Following RFC 7230, if the enabled_import_methods is empty,
the header is not returned with the response.

Change-Id: I3066da36a0fbb83fe492bddb193975e42ffc5084
Closes-bug: #1748559
---
 glance/api/v2/images.py                      | 13 +++---
 glance/tests/unit/v2/test_images_resource.py | 45 ++++++++++++++++++++
 2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/glance/api/v2/images.py b/glance/api/v2/images.py
index a736219842..b78b79d840 100644
--- a/glance/api/v2/images.py
+++ b/glance/api/v2/images.py
@@ -892,12 +892,15 @@ class ResponseSerializer(wsgi.JSONResponseSerializer):
         response.status_int = http.CREATED
         self.show(response, image)
         response.location = self._get_image_href(image)
-        # TODO(jokke): make this configurable when swift-local is implemented
-        # and remove the if statement with the config option.
+        # TODO(rosmaita): remove the outer 'if' statement when the
+        # enable_image_import config option is removed
         if CONF.enable_image_import:
-            import_methods = ("OpenStack-image-import-methods",
-                              "glance-direct")
-            response.headerlist.append(import_methods)
+            # according to RFC7230, headers should not have empty fields
+            # see http://httpwg.org/specs/rfc7230.html#field.components
+            if CONF.enabled_import_methods:
+                import_methods = ("OpenStack-image-import-methods",
+                                  ','.join(CONF.enabled_import_methods))
+                response.headerlist.append(import_methods)
 
     def show(self, response, image):
         image_view = self._format_image(image)
diff --git a/glance/tests/unit/v2/test_images_resource.py b/glance/tests/unit/v2/test_images_resource.py
index f2ceeafb49..f0408a5fd8 100644
--- a/glance/tests/unit/v2/test_images_resource.py
+++ b/glance/tests/unit/v2/test_images_resource.py
@@ -3567,6 +3567,51 @@ class TestImagesSerializer(test_utils.BaseTestCase):
         self.assertEqual('application/json', response.content_type)
         self.assertEqual('/v2/images/%s' % UUID1, response.location)
 
+    def test_create_has_import_methods_header(self):
+        # NOTE(rosmaita): enabled_import_methods is defined as type
+        # oslo.config.cfg.ListOpt, so it is stored internally as a list
+        # but is converted to a string for output in the HTTP header
+
+        header_name = 'OpenStack-image-import-methods'
+
+        # check multiple methods
+        enabled_methods = ['one', 'two', 'three']
+        self.config(enabled_import_methods=enabled_methods)
+        response = webob.Response()
+        self.serializer.create(response, self.fixtures[0])
+        self.assertEqual(http.CREATED, response.status_int)
+        header_value = response.headers.get(header_name)
+        self.assertIsNotNone(header_value)
+        self.assertItemsEqual(enabled_methods, header_value.split(','))
+
+        # check single method
+        self.config(enabled_import_methods=['swift-party-time'])
+        response = webob.Response()
+        self.serializer.create(response, self.fixtures[0])
+        self.assertEqual(http.CREATED, response.status_int)
+        header_value = response.headers.get(header_name)
+        self.assertIsNotNone(header_value)
+        self.assertEqual('swift-party-time', header_value)
+
+        # no header for empty config value
+        self.config(enabled_import_methods=[])
+        response = webob.Response()
+        self.serializer.create(response, self.fixtures[0])
+        self.assertEqual(http.CREATED, response.status_int)
+        headers = response.headers.keys()
+        self.assertNotIn(header_name, headers)
+
+    # TODO(rosmaita): remove this test when the enable_image_import
+    # option is removed
+    def test_create_has_no_import_methods_header(self):
+        header_name = 'OpenStack-image-import-methods'
+        self.config(enable_image_import=False)
+        response = webob.Response()
+        self.serializer.create(response, self.fixtures[0])
+        self.assertEqual(http.CREATED, response.status_int)
+        headers = response.headers.keys()
+        self.assertNotIn(header_name, headers)
+
     def test_update(self):
         expected = {
             'id': UUID1,