Add a new configuration variable for api links.

Currently we use WebOb.request.application_url to return a link to the
neutron api. This may not be the correct link in the case where
'X-Forwarded-Proto' is used. Nova provides the osapi_compute_link_prefix
variable for providing custom links to the api. This does the same
for Neutron.

Co-Authored-By: Kevin Benton <kevin@benton.pub>
Change-Id: I92227803b1bc2fec10ee168a0285f2f6f09f55b0

neutron/api/api_common.py

@@ -72,7 +72,7 @@ def get_previous_link(request, items, id_key):
         marker = items[0][id_key]
         params['marker'] = marker
     params['page_reverse'] = True
-    return "%s?%s" % (request.path_url, parse.urlencode(params))
+    return "%s?%s" % (prepare_url(request.path_url), parse.urlencode(params))
 
 
 def get_next_link(request, items, id_key):
@@ -82,7 +82,20 @@ def get_next_link(request, items, id_key):
         marker = items[-1][id_key]
         params['marker'] = marker
     params.pop('page_reverse', None)
-    return "%s?%s" % (request.path_url, parse.urlencode(params))
+    return "%s?%s" % (prepare_url(request.path_url), parse.urlencode(params))
+
+
+def prepare_url(orig_url):
+    """Takes a link and swaps in network_link_prefix if set."""
+    prefix = cfg.CONF.network_link_prefix
+    # Copied directly from nova/api/openstack/common.py
+    if not prefix:
+        return orig_url
+    url_parts = list(parse.urlsplit(orig_url))
+    prefix_parts = list(parse.urlsplit(prefix))
+    url_parts[0:2] = prefix_parts[0:2]
+    url_parts[2] = prefix_parts[2] + url_parts[2]
+    return parse.urlunsplit(url_parts).rstrip('/')
 
 
 def get_limit_and_marker(request):

neutron/api/views/versions.py

@@ -15,6 +15,8 @@
 
 import os
 
+from neutron.api import api_common
+
 
 def get_view_builder(req):
     base_url = req.application_url
@@ -28,7 +30,7 @@ class ViewBuilder(object):
 
         :param base_url: url of the root wsgi application
         """
-        self.base_url = base_url
+        self.base_url = api_common.prepare_url(base_url)
 
     def build(self, version_data):
         """Generic method used to generate a version entity."""

neutron/conf/common.py

@@ -102,6 +102,11 @@ core_opts = [
                       "services running on this machine. All the agents and "
                       "services running on this machine must use the same "
                       "host value.")),
+    cfg.StrOpt("network_link_prefix",
+               help=_("This string is prepended to the normal URL that is "
+                      "returned in links to the OpenStack Network API. If it "
+                      "is empty (the default), the URLs are returned "
+                      "unchanged.")),
     cfg.BoolOpt('notify_nova_on_port_status_changes', default=True,
                 help=_("Send notification to nova when port status changes")),
     cfg.BoolOpt('notify_nova_on_port_data_changes', default=True,

neutron/tests/unit/api/test_api_common.py

@@ -0,0 +1,33 @@
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from oslo_config import cfg
+
+from neutron.api import api_common
+from neutron.tests import base
+
+
+class PrepareUrlTestCase(base.BaseTestCase):
+
+    def test_no_configured_prefix(self):
+        self.assertFalse(cfg.CONF.network_link_prefix)
+        requrl = 'http://neutron.example/sub/ports.json?test=1'
+        # should be unchanged
+        self.assertEqual(requrl, api_common.prepare_url(requrl))
+
+    def test_configured_prefix(self):
+        cfg.CONF.set_override('network_link_prefix', 'http://quantum.example')
+        requrl = 'http://neutron.example/sub/ports.json?test=1'
+        expected = 'http://quantum.example/sub/ports.json?test=1'
+        self.assertEqual(expected, api_common.prepare_url(requrl))

releasenotes/notes/network_link_prefix-e3fe37e37ea275b7.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    A new ``network_link_prefix`` configuration option is introduced that allows to
+    alter the domain returned in the URLs included in the API responses. It behaves the
+    same way as the ``compute_link_prefix`` and ``glance_link_prefix``
+    options do for Nova and Glance.