Support inexact filtering on attributes

Being able to specify inexact filters on attributes is an important
part of ensuring the size of collections returned by list API calls
is minimized

DocImpact

Partially implements bp filtering-backend-support

Change-Id: If81f6644217f121afeed00b867f369ec257e63b3

openstack-identity-api/v3/src/markdown/identity-api-v3.md

@@ -18,6 +18,7 @@ These features are not yet considered stable (expected January 2014).
   validation.
 - Introduced a region resource for constructing a hierarchical container
   of groups of service endpoints
+- Inexact filtering is supported on string attributes
 
 What's New in Version 3.1
 -------------------------
@@ -269,6 +270,11 @@ with one or more attribute/value pairs:
 
     GET /entities?name={entity_name}&enabled={entity_enabled}
 
+If multiple filters are specified in a query, then all filters must match for
+an entity to be included in the response. The values specified in a filter
+must be of the same type as the attribute, and in the case of strings are
+limited to the same maximum length as the attribute.
+
 The response is a subset of the full collection:
 
     200 OK
@@ -292,6 +298,45 @@ The response is a subset of the full collection:
         }
     }
 
+*New in version 3.2* String attributes may also be filtered using inexact
+patterns, for example:
+
+    GET /entities?name__startswith={initial_characters_of_entity_name}
+
+The following inexact suffixes are supported:
+
+- `__startswith`
+
+  Matches if the attribute starts with the characters specified, with the
+  comparison being case-sensitive.
+
+- `__istartswith`
+
+  Matches if the attribute starts with the characters specified, with the
+  comparison being case-insensitive.
+
+- `__endswith`
+
+  Matches if the attribute ends with the characters specified, with the
+  comparison being case-sensitive.
+
+- `__iendswith`
+
+  Matches if the attribute ends with the characters specified, with the
+  comparison being case-insensitive.
+
+- `__contains`
+
+  Matches if the attribute contains the characters specified, with the
+  comparison being case-sensitive.
+
+- `__icontains`
+
+  Matches if the attribute contains the characters specified, with the
+  comparison being case-insensitive.
+
+Inexact filters specified for non-string attributes will be ignored.
+
 #### Get an Entity
 
 Request a specific entity by ID: