Added xml schema validation for extensions resources.

Added corresponding xml schemas.
Added lxml dep, which is needed for doing xml schema validation.

6 files changed, 809 insertions, 14 deletions

diff --git a/nova/api/openstack/extensions.py b/nova/api/openstack/extensions.py
index cc889703e..6188e274d 100644
--- a/nova/api/openstack/extensions.py
+++ b/nova/api/openstack/extensions.py
@@ -23,7 +23,7 @@ import sys
 import routes
 import webob.dec
 import webob.exc
-from xml.etree import ElementTree
+from lxml import etree
 
 from nova import exception
 from nova import flags
@@ -32,6 +32,7 @@ from nova import wsgi as base_wsgi
 from nova.api.openstack import common
 from nova.api.openstack import faults
 from nova.api.openstack import wsgi
+from nova.api.openstack import xmlutil
 
 
 LOG = logging.getLogger('extensions')
@@ -470,36 +471,38 @@ class ResourceExtension(object):
 
 class ExtensionsXMLSerializer(wsgi.XMLDictSerializer):
 
+    NSMAP = {None: xmlutil.XMLNS_V11, 'atom': xmlutil.XMLNS_ATOM}
+
     def show(self, ext_dict):
-        ext = self._create_ext_elem(ext_dict['extension'])
+        ext = etree.Element('extension', nsmap=self.NSMAP)
+        self._populate_ext(ext, ext_dict['extension'])
         return self._to_xml(ext)
 
     def index(self, exts_dict):
-        exts = ElementTree.Element('extensions')
+        exts = etree.Element('extensions', nsmap=self.NSMAP)
         for ext_dict in exts_dict['extensions']:
-            exts.append(self._create_ext_elem(ext_dict))
+            ext = etree.SubElement(exts, 'extension')
+            self._populate_ext(ext, ext_dict)
         return self._to_xml(exts)
 
-    def _create_ext_elem(self, ext_dict):
-        """Create an extension xml element from a dict."""
-        ext_elem = ElementTree.Element('extension')
+    def _populate_ext(self, ext_elem, ext_dict):
+        """Populate an extension xml element from a dict."""
+
         ext_elem.set('name', ext_dict['name'])
         ext_elem.set('namespace', ext_dict['namespace'])
         ext_elem.set('alias', ext_dict['alias'])
         ext_elem.set('updated', ext_dict['updated'])
-        desc = ElementTree.Element('description')
+        desc = etree.Element('description')
         desc.text = ext_dict['description']
         ext_elem.append(desc)
         for link in ext_dict.get('links', []):
-            elem = ElementTree.Element('atom:link')
+            elem = etree.SubElement(ext_elem, '{%s}link' % xmlutil.XMLNS_ATOM)
             elem.set('rel', link['rel'])
             elem.set('href', link['href'])
             elem.set('type', link['type'])
-            ext_elem.append(elem)
         return ext_elem
 
     def _to_xml(self, root):
-        """Convert the xml tree object to an xml string."""
-        root.set('xmlns', wsgi.XMLNS_V11)
-        root.set('xmlns:atom', wsgi.XMLNS_ATOM)
-        return ElementTree.tostring(root, encoding='UTF-8')
+        """Convert the xml object to an xml string."""
+
+        return etree.tostring(root, encoding='UTF-8')
diff --git a/nova/api/openstack/schemas/atom-link.rng b/nova/api/openstack/schemas/atom-link.rng
new file mode 100644
index 000000000..edba5eee6
--- /dev/null
+++ b/nova/api/openstack/schemas/atom-link.rng
@@ -0,0 +1,141 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  -*- rnc -*-
+  RELAX NG Compact Syntax Grammar for the
+  Atom Format Specification Version 11
+-->
+<grammar xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:s="http://www.ascc.net/xml/schematron" xmlns="http://relaxng.org/ns/structure/1.0" datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
+  <start>
+    <choice>
+      <ref name="atomLink"/>
+    </choice>
+  </start>
+  <!-- Common attributes -->
+  <define name="atomCommonAttributes">
+    <optional>
+      <attribute name="xml:base">
+        <ref name="atomUri"/>
+      </attribute>
+    </optional>
+    <optional>
+      <attribute name="xml:lang">
+        <ref name="atomLanguageTag"/>
+      </attribute>
+    </optional>
+    <zeroOrMore>
+      <ref name="undefinedAttribute"/>
+    </zeroOrMore>
+  </define>
+  <!-- atom:link -->
+  <define name="atomLink">
+    <element name="atom:link">
+      <ref name="atomCommonAttributes"/>
+      <attribute name="href">
+        <ref name="atomUri"/>
+      </attribute>
+      <optional>
+        <attribute name="rel">
+          <choice>
+            <ref name="atomNCName"/>
+            <ref name="atomUri"/>
+          </choice>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="type">
+          <ref name="atomMediaType"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="hreflang">
+          <ref name="atomLanguageTag"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="title"/>
+      </optional>
+      <optional>
+        <attribute name="length"/>
+      </optional>
+      <ref name="undefinedContent"/>
+    </element>
+  </define>
+  <!-- Low-level simple types -->
+  <define name="atomNCName">
+    <data type="string">
+      <param name="minLength">1</param>
+      <param name="pattern">[^:]*</param>
+    </data>
+  </define>
+  <!-- Whatever a media type is, it contains at least one slash -->
+  <define name="atomMediaType">
+    <data type="string">
+      <param name="pattern">.+/.+</param>
+    </data>
+  </define>
+  <!-- As defined in RFC 3066 -->
+  <define name="atomLanguageTag">
+    <data type="string">
+      <param name="pattern">[A-Za-z]{1,8}(-[A-Za-z0-9]{1,8})*</param>
+    </data>
+  </define>
+  <!--
+    Unconstrained; it's not entirely clear how IRI fit into
+    xsd:anyURI so let's not try to constrain it here
+  -->
+  <define name="atomUri">
+    <text/>
+  </define>
+  <!-- Other Extensibility -->
+  <define name="undefinedAttribute">
+    <attribute>
+      <anyName>
+        <except>
+          <name>xml:base</name>
+          <name>xml:lang</name>
+          <nsName ns=""/>
+        </except>
+      </anyName>
+    </attribute>
+  </define>
+  <define name="undefinedContent">
+    <zeroOrMore>
+      <choice>
+        <text/>
+        <ref name="anyForeignElement"/>
+      </choice>
+    </zeroOrMore>
+  </define>
+  <define name="anyElement">
+    <element>
+      <anyName/>
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyElement"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+  <define name="anyForeignElement">
+    <element>
+      <anyName>
+        <except>
+          <nsName ns="http://www.w3.org/2005/Atom"/>
+        </except>
+      </anyName>
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyElement"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+</grammar>
diff --git a/nova/api/openstack/schemas/atom.rng b/nova/api/openstack/schemas/atom.rng
new file mode 100644
index 000000000..c2df4e410
--- /dev/null
+++ b/nova/api/openstack/schemas/atom.rng
@@ -0,0 +1,597 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  -*- rnc -*-
+  RELAX NG Compact Syntax Grammar for the
+  Atom Format Specification Version 11
+-->
+<grammar xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:s="http://www.ascc.net/xml/schematron" xmlns="http://relaxng.org/ns/structure/1.0" datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
+  <start>
+    <choice>
+      <ref name="atomFeed"/>
+      <ref name="atomEntry"/>
+    </choice>
+  </start>
+  <!-- Common attributes -->
+  <define name="atomCommonAttributes">
+    <optional>
+      <attribute name="xml:base">
+        <ref name="atomUri"/>
+      </attribute>
+    </optional>
+    <optional>
+      <attribute name="xml:lang">
+        <ref name="atomLanguageTag"/>
+      </attribute>
+    </optional>
+    <zeroOrMore>
+      <ref name="undefinedAttribute"/>
+    </zeroOrMore>
+  </define>
+  <!-- Text Constructs -->
+  <define name="atomPlainTextConstruct">
+    <ref name="atomCommonAttributes"/>
+    <optional>
+      <attribute name="type">
+        <choice>
+          <value>text</value>
+          <value>html</value>
+        </choice>
+      </attribute>
+    </optional>
+    <text/>
+  </define>
+  <define name="atomXHTMLTextConstruct">
+    <ref name="atomCommonAttributes"/>
+    <attribute name="type">
+      <value>xhtml</value>
+    </attribute>
+    <ref name="xhtmlDiv"/>
+  </define>
+  <define name="atomTextConstruct">
+    <choice>
+      <ref name="atomPlainTextConstruct"/>
+      <ref name="atomXHTMLTextConstruct"/>
+    </choice>
+  </define>
+  <!-- Person Construct -->
+  <define name="atomPersonConstruct">
+    <ref name="atomCommonAttributes"/>
+    <interleave>
+      <element name="atom:name">
+        <text/>
+      </element>
+      <optional>
+        <element name="atom:uri">
+          <ref name="atomUri"/>
+        </element>
+      </optional>
+      <optional>
+        <element name="atom:email">
+          <ref name="atomEmailAddress"/>
+        </element>
+      </optional>
+      <zeroOrMore>
+        <ref name="extensionElement"/>
+      </zeroOrMore>
+    </interleave>
+  </define>
+  <!-- Date Construct -->
+  <define name="atomDateConstruct">
+    <ref name="atomCommonAttributes"/>
+    <data type="dateTime"/>
+  </define>
+  <!-- atom:feed -->
+  <define name="atomFeed">
+    <element name="atom:feed">
+      <s:rule context="atom:feed">
+        <s:assert test="atom:author or not(atom:entry[not(atom:author)])">An atom:feed must have an atom:author unless all of its atom:entry children have an atom:author.</s:assert>
+      </s:rule>
+      <ref name="atomCommonAttributes"/>
+      <interleave>
+        <zeroOrMore>
+          <ref name="atomAuthor"/>
+        </zeroOrMore>
+        <zeroOrMore>
+          <ref name="atomCategory"/>
+        </zeroOrMore>
+        <zeroOrMore>
+          <ref name="atomContributor"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomGenerator"/>
+        </optional>
+        <optional>
+          <ref name="atomIcon"/>
+        </optional>
+        <ref name="atomId"/>
+        <zeroOrMore>
+          <ref name="atomLink"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomLogo"/>
+        </optional>
+        <optional>
+          <ref name="atomRights"/>
+        </optional>
+        <optional>
+          <ref name="atomSubtitle"/>
+        </optional>
+        <ref name="atomTitle"/>
+        <ref name="atomUpdated"/>
+        <zeroOrMore>
+          <ref name="extensionElement"/>
+        </zeroOrMore>
+      </interleave>
+      <zeroOrMore>
+        <ref name="atomEntry"/>
+      </zeroOrMore>
+    </element>
+  </define>
+  <!-- atom:entry -->
+  <define name="atomEntry">
+    <element name="atom:entry">
+      <s:rule context="atom:entry">
+        <s:assert test="atom:link[@rel='alternate'] or atom:link[not(@rel)] or atom:content">An atom:entry must have at least one atom:link element with a rel attribute of 'alternate' or an atom:content.</s:assert>
+      </s:rule>
+      <s:rule context="atom:entry">
+        <s:assert test="atom:author or ../atom:author or atom:source/atom:author">An atom:entry must have an atom:author if its feed does not.</s:assert>
+      </s:rule>
+      <ref name="atomCommonAttributes"/>
+      <interleave>
+        <zeroOrMore>
+          <ref name="atomAuthor"/>
+        </zeroOrMore>
+        <zeroOrMore>
+          <ref name="atomCategory"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomContent"/>
+        </optional>
+        <zeroOrMore>
+          <ref name="atomContributor"/>
+        </zeroOrMore>
+        <ref name="atomId"/>
+        <zeroOrMore>
+          <ref name="atomLink"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomPublished"/>
+        </optional>
+        <optional>
+          <ref name="atomRights"/>
+        </optional>
+        <optional>
+          <ref name="atomSource"/>
+        </optional>
+        <optional>
+          <ref name="atomSummary"/>
+        </optional>
+        <ref name="atomTitle"/>
+        <ref name="atomUpdated"/>
+        <zeroOrMore>
+          <ref name="extensionElement"/>
+        </zeroOrMore>
+      </interleave>
+    </element>
+  </define>
+  <!-- atom:content -->
+  <define name="atomInlineTextContent">
+    <element name="atom:content">
+      <ref name="atomCommonAttributes"/>
+      <optional>
+        <attribute name="type">
+          <choice>
+            <value>text</value>
+            <value>html</value>
+          </choice>
+        </attribute>
+      </optional>
+      <zeroOrMore>
+        <text/>
+      </zeroOrMore>
+    </element>
+  </define>
+  <define name="atomInlineXHTMLContent">
+    <element name="atom:content">
+      <ref name="atomCommonAttributes"/>
+      <attribute name="type">
+        <value>xhtml</value>
+      </attribute>
+      <ref name="xhtmlDiv"/>
+    </element>
+  </define>
+  <define name="atomInlineOtherContent">
+    <element name="atom:content">
+      <ref name="atomCommonAttributes"/>
+      <optional>
+        <attribute name="type">
+          <ref name="atomMediaType"/>
+        </attribute>
+      </optional>
+      <zeroOrMore>
+        <choice>
+          <text/>
+          <ref name="anyElement"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+  <define name="atomOutOfLineContent">
+    <element name="atom:content">
+      <ref name="atomCommonAttributes"/>
+      <optional>
+        <attribute name="type">
+          <ref name="atomMediaType"/>
+        </attribute>
+      </optional>
+      <attribute name="src">
+        <ref name="atomUri"/>
+      </attribute>
+      <empty/>
+    </element>
+  </define>
+  <define name="atomContent">
+    <choice>
+      <ref name="atomInlineTextContent"/>
+      <ref name="atomInlineXHTMLContent"/>
+      <ref name="atomInlineOtherContent"/>
+      <ref name="atomOutOfLineContent"/>
+    </choice>
+  </define>
+  <!-- atom:author -->
+  <define name="atomAuthor">
+    <element name="atom:author">
+      <ref name="atomPersonConstruct"/>
+    </element>
+  </define>
+  <!-- atom:category -->
+  <define name="atomCategory">
+    <element name="atom:category">
+      <ref name="atomCommonAttributes"/>
+      <attribute name="term"/>
+      <optional>
+        <attribute name="scheme">
+          <ref name="atomUri"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="label"/>
+      </optional>
+      <ref name="undefinedContent"/>
+    </element>
+  </define>
+  <!-- atom:contributor -->
+  <define name="atomContributor">
+    <element name="atom:contributor">
+      <ref name="atomPersonConstruct"/>
+    </element>
+  </define>
+  <!-- atom:generator -->
+  <define name="atomGenerator">
+    <element name="atom:generator">
+      <ref name="atomCommonAttributes"/>
+      <optional>
+        <attribute name="uri">
+          <ref name="atomUri"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="version"/>
+      </optional>
+      <text/>
+    </element>
+  </define>
+  <!-- atom:icon -->
+  <define name="atomIcon">
+    <element name="atom:icon">
+      <ref name="atomCommonAttributes"/>
+      <ref name="atomUri"/>
+    </element>
+  </define>
+  <!-- atom:id -->
+  <define name="atomId">
+    <element name="atom:id">
+      <ref name="atomCommonAttributes"/>
+      <ref name="atomUri"/>
+    </element>
+  </define>
+  <!-- atom:logo -->
+  <define name="atomLogo">
+    <element name="atom:logo">
+      <ref name="atomCommonAttributes"/>
+      <ref name="atomUri"/>
+    </element>
+  </define>
+  <!-- atom:link -->
+  <define name="atomLink">
+    <element name="atom:link">
+      <ref name="atomCommonAttributes"/>
+      <attribute name="href">
+        <ref name="atomUri"/>
+      </attribute>
+      <optional>
+        <attribute name="rel">
+          <choice>
+            <ref name="atomNCName"/>
+            <ref name="atomUri"/>
+          </choice>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="type">
+          <ref name="atomMediaType"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="hreflang">
+          <ref name="atomLanguageTag"/>
+        </attribute>
+      </optional>
+      <optional>
+        <attribute name="title"/>
+      </optional>
+      <optional>
+        <attribute name="length"/>
+      </optional>
+      <ref name="undefinedContent"/>
+    </element>
+  </define>
+  <!-- atom:published -->
+  <define name="atomPublished">
+    <element name="atom:published">
+      <ref name="atomDateConstruct"/>
+    </element>
+  </define>
+  <!-- atom:rights -->
+  <define name="atomRights">
+    <element name="atom:rights">
+      <ref name="atomTextConstruct"/>
+    </element>
+  </define>
+  <!-- atom:source -->
+  <define name="atomSource">
+    <element name="atom:source">
+      <ref name="atomCommonAttributes"/>
+      <interleave>
+        <zeroOrMore>
+          <ref name="atomAuthor"/>
+        </zeroOrMore>
+        <zeroOrMore>
+          <ref name="atomCategory"/>
+        </zeroOrMore>
+        <zeroOrMore>
+          <ref name="atomContributor"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomGenerator"/>
+        </optional>
+        <optional>
+          <ref name="atomIcon"/>
+        </optional>
+        <optional>
+          <ref name="atomId"/>
+        </optional>
+        <zeroOrMore>
+          <ref name="atomLink"/>
+        </zeroOrMore>
+        <optional>
+          <ref name="atomLogo"/>
+        </optional>
+        <optional>
+          <ref name="atomRights"/>
+        </optional>
+        <optional>
+          <ref name="atomSubtitle"/>
+        </optional>
+        <optional>
+          <ref name="atomTitle"/>
+        </optional>
+        <optional>
+          <ref name="atomUpdated"/>
+        </optional>
+        <zeroOrMore>
+          <ref name="extensionElement"/>
+        </zeroOrMore>
+      </interleave>
+    </element>
+  </define>
+  <!-- atom:subtitle -->
+  <define name="atomSubtitle">
+    <element name="atom:subtitle">
+      <ref name="atomTextConstruct"/>
+    </element>
+  </define>
+  <!-- atom:summary -->
+  <define name="atomSummary">
+    <element name="atom:summary">
+      <ref name="atomTextConstruct"/>
+    </element>
+  </define>
+  <!-- atom:title -->
+  <define name="atomTitle">
+    <element name="atom:title">
+      <ref name="atomTextConstruct"/>
+    </element>
+  </define>
+  <!-- atom:updated -->
+  <define name="atomUpdated">
+    <element name="atom:updated">
+      <ref name="atomDateConstruct"/>
+    </element>
+  </define>
+  <!-- Low-level simple types -->
+  <define name="atomNCName">
+    <data type="string">
+      <param name="minLength">1</param>
+      <param name="pattern">[^:]*</param>
+    </data>
+  </define>
+  <!-- Whatever a media type is, it contains at least one slash -->
+  <define name="atomMediaType">
+    <data type="string">
+      <param name="pattern">.+/.+</param>
+    </data>
+  </define>
+  <!-- As defined in RFC 3066 -->
+  <define name="atomLanguageTag">
+    <data type="string">
+      <param name="pattern">[A-Za-z]{1,8}(-[A-Za-z0-9]{1,8})*</param>
+    </data>
+  </define>
+  <!--
+    Unconstrained; it's not entirely clear how IRI fit into
+    xsd:anyURI so let's not try to constrain it here
+  -->
+  <define name="atomUri">
+    <text/>
+  </define>
+  <!-- Whatever an email address is, it contains at least one @ -->
+  <define name="atomEmailAddress">
+    <data type="string">
+      <param name="pattern">.+@.+</param>
+    </data>
+  </define>
+  <!-- Simple Extension -->
+  <define name="simpleExtensionElement">
+    <element>
+      <anyName>
+        <except>
+          <nsName ns="http://www.w3.org/2005/Atom"/>
+        </except>
+      </anyName>
+      <text/>
+    </element>
+  </define>
+  <!-- Structured Extension -->
+  <define name="structuredExtensionElement">
+    <element>
+      <anyName>
+        <except>
+          <nsName ns="http://www.w3.org/2005/Atom"/>
+        </except>
+      </anyName>
+      <choice>
+        <group>
+          <oneOrMore>
+            <attribute>
+              <anyName/>
+            </attribute>
+          </oneOrMore>
+          <zeroOrMore>
+            <choice>
+              <text/>
+              <ref name="anyElement"/>
+            </choice>
+          </zeroOrMore>
+        </group>
+        <group>
+          <zeroOrMore>
+            <attribute>
+              <anyName/>
+            </attribute>
+          </zeroOrMore>
+          <group>
+            <optional>
+              <text/>
+            </optional>
+            <oneOrMore>
+              <ref name="anyElement"/>
+            </oneOrMore>
+            <zeroOrMore>
+              <choice>
+                <text/>
+                <ref name="anyElement"/>
+              </choice>
+            </zeroOrMore>
+          </group>
+        </group>
+      </choice>
+    </element>
+  </define>
+  <!-- Other Extensibility -->
+  <define name="extensionElement">
+    <choice>
+      <ref name="simpleExtensionElement"/>
+      <ref name="structuredExtensionElement"/>
+    </choice>
+  </define>
+  <define name="undefinedAttribute">
+    <attribute>
+      <anyName>
+        <except>
+          <name>xml:base</name>
+          <name>xml:lang</name>
+          <nsName ns=""/>
+        </except>
+      </anyName>
+    </attribute>
+  </define>
+  <define name="undefinedContent">
+    <zeroOrMore>
+      <choice>
+        <text/>
+        <ref name="anyForeignElement"/>
+      </choice>
+    </zeroOrMore>
+  </define>
+  <define name="anyElement">
+    <element>
+      <anyName/>
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyElement"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+  <define name="anyForeignElement">
+    <element>
+      <anyName>
+        <except>
+          <nsName ns="http://www.w3.org/2005/Atom"/>
+        </except>
+      </anyName>
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyElement"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+  <!-- XHTML -->
+  <define name="anyXHTML">
+    <element>
+      <nsName ns="http://www.w3.org/1999/xhtml"/>
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyXHTML"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+  <define name="xhtmlDiv">
+    <element name="xhtml:div">
+      <zeroOrMore>
+        <choice>
+          <attribute>
+            <anyName/>
+          </attribute>
+          <text/>
+          <ref name="anyXHTML"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
+</grammar>
diff --git a/nova/api/openstack/schemas/v1.1/extension.rng b/nova/api/openstack/schemas/v1.1/extension.rng
new file mode 100644
index 000000000..336659755
--- /dev/null
+++ b/nova/api/openstack/schemas/v1.1/extension.rng
@@ -0,0 +1,11 @@
+<element name="extension" ns="http://docs.openstack.org/compute/api/v1.1"
+    xmlns="http://relaxng.org/ns/structure/1.0">
+  <attribute name="alias">     <text/> </attribute>
+  <attribute name="name">      <text/> </attribute>
+  <attribute name="namespace"> <text/> </attribute>
+  <attribute name="updated">   <text/> </attribute>
+  <element name="description"> <text/> </element>
+  <zeroOrMore>
+    <externalRef href="../atom-link.rng"/>
+  </zeroOrMore>
+</element>
diff --git a/nova/api/openstack/schemas/v1.1/extensions.rng b/nova/api/openstack/schemas/v1.1/extensions.rng
new file mode 100644
index 000000000..4d8bff646
--- /dev/null
+++ b/nova/api/openstack/schemas/v1.1/extensions.rng
@@ -0,0 +1,6 @@
+<element name="extensions" xmlns="http://relaxng.org/ns/structure/1.0"
+         ns="http://docs.openstack.org/compute/api/v1.1">
+  <zeroOrMore>
+    <externalRef href="extension.rng"/>
+  </zeroOrMore>
+</element>
diff --git a/nova/api/openstack/xmlutil.py b/nova/api/openstack/xmlutil.py
new file mode 100644
index 000000000..97ad90ada
--- /dev/null
+++ b/nova/api/openstack/xmlutil.py
@@ -0,0 +1,37 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack LLC.
+# 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.
+
+import os.path
+
+from lxml import etree
+
+from nova import utils
+
+
+XMLNS_V10 = 'http://docs.rackspacecloud.com/servers/api/v1.0'
+XMLNS_V11 = 'http://docs.openstack.org/compute/api/v1.1'
+XMLNS_ATOM = 'http://www.w3.org/2005/Atom'
+
+
+def validate_schema(xml, schema_name):
+    if type(xml) is str:
+        xml = etree.fromstring(xml)
+    schema_path = os.path.join(utils.novadir(),
+        'nova/api/openstack/schemas/v1.1/%s.rng' % schema_name)
+    schema_doc = etree.parse(schema_path)
+    relaxng = etree.RelaxNG(schema_doc)
+    relaxng.assertValid(xml)