Update the segment api extension

The segment api definition is changed in server side [1]. This patch
sync up the definition in neutron-lib. In addition, remove the
dependency from standard-attr-segment on segment since the
dependency is reserved: we have segment depending on
standard-attr-segment with the latest change.

[1] https://review.openstack.org/#/c/571292/

Change-Id: I64780fc435da98d9b5d4e58c9e61d3d0b11d0daf

neutron_lib/api/definitions/base.py

@@ -122,6 +122,7 @@ KNOWN_EXTENSIONS = (
     'sorting',
     'standard-attr-description',
     'standard-attr-revisions',
+    'standard-attr-segment',
     'standard-attr-timestamp',
     'subnet_allocation',
     'subnet_onboard',

neutron_lib/api/definitions/segment.py

@@ -104,15 +104,6 @@ RESOURCE_ATTRIBUTE_MAP = {
             'is_filter': True,
             'is_sort_key': True,
             'is_visible': True
-        },
-        'description': {
-            'allow_post': True,
-            'allow_put': True,
-            'default': constants.ATTR_NOT_SPECIFIED,
-            'validate': {
-                'type:string_or_none': DESC_LEN
-            },
-            'is_visible': True
         }
     },
     subnet.COLLECTION_NAME: {
@@ -131,6 +122,11 @@ RESOURCE_ATTRIBUTE_MAP = {
 }
 SUB_RESOURCE_ATTRIBUTE_MAP = {}
 ACTION_MAP = {}
-REQUIRED_EXTENSIONS = []
+REQUIRED_EXTENSIONS = [
-OPTIONAL_EXTENSIONS = []
+    'standard-attr-description'
+]
+OPTIONAL_EXTENSIONS = [
+    # Use string instead of constant to avoid circulated import
+    'standard-attr-segment'
+]
 ACTION_STATUS = {}

releasenotes/notes/update-segment-api-definition-d7297e73e76a754c.yaml

@@ -0,0 +1,7 @@
+---
+other:
+  - |
+    This release removes the ``description`` from the segment extension's
+    attribute map as well as adds the ``standard-attr-description`` as
+    required dependency and ``standard-attr-segment`` as an optional
+    dependency.