Clean up ElementTree usage

Use lxml in favor of ElementTree to
make things more consistent.

Fixes LP: #953449

Change-Id: I7f48528d7df47fe7207ca88bce196dea7535df0e
Signed-off-by: Chuck Short <chuck.short@canonical.com>

8 files changed, 51 insertions, 57 deletions

diff --git a/nova/image/s3.py b/nova/image/s3.py
index fdf955515..1b8b76596 100644
--- a/nova/image/s3.py
+++ b/nova/image/s3.py
@@ -24,10 +24,10 @@ import os
 import shutil
 import tarfile
 import tempfile
-from xml.etree import ElementTree
 
 import boto.s3.connection
 import eventlet
+from lxml import etree
 
 from nova import rpc
 from nova import exception
@@ -180,7 +180,7 @@ class S3ImageService(object):
         return local_filename
 
     def _s3_parse_manifest(self, context, metadata, manifest):
-        manifest = ElementTree.fromstring(manifest)
+        manifest = etree.fromstring(manifest)
         image_format = 'ami'
         image_type = 'machine'
 
diff --git a/nova/tests/api/ec2/test_middleware.py b/nova/tests/api/ec2/test_middleware.py
index 62e12abaa..d032d1ea3 100644
--- a/nova/tests/api/ec2/test_middleware.py
+++ b/nova/tests/api/ec2/test_middleware.py
@@ -16,6 +16,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from lxml import etree
 import webob
 import webob.dec
 import webob.exc
@@ -27,8 +28,6 @@ from nova import flags
 from nova import test
 from nova import utils
 
-from xml.etree import ElementTree
-
 FLAGS = flags.FLAGS
 
 
@@ -108,7 +107,7 @@ class ExecutorTestCase(test.TestCase):
         return self.executor(fake_wsgi_request)
 
     def _extract_message(self, result):
-        tree = ElementTree.fromstring(result.body)
+        tree = etree.fromstring(result.body)
         return tree.findall('./Errors')[0].find('Error/Message').text
 
     def test_instance_not_found(self):
diff --git a/nova/tests/fakelibvirt.py b/nova/tests/fakelibvirt.py
index 24ff5ae55..5a317dca1 100644
--- a/nova/tests/fakelibvirt.py
+++ b/nova/tests/fakelibvirt.py
@@ -14,12 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from xml.etree import ElementTree
-try:
-    ParseError = ElementTree.ParseError
-except AttributeError:
-    from xml.parsers import expat
-    ParseError = expat.ExpatError
+from lxml import etree
 
 import uuid
 
@@ -141,7 +136,7 @@ class NWFilter(object):
         self._parse_xml(xml)
 
     def _parse_xml(self, xml):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         root = tree.find('.')
         self._name = root.get('name')
 
@@ -163,8 +158,8 @@ class Domain(object):
 
     def _parse_definition(self, xml):
         try:
-            tree = ElementTree.fromstring(xml)
-        except ParseError:
+            tree = etree.fromstring(xml)
+        except etree.ParseError:
             raise libvirtError(VIR_ERR_XML_DETAIL, VIR_FROM_DOMAIN,
                                "Invalid XML.")
 
@@ -301,13 +296,13 @@ class Domain(object):
                 123456789L]
 
     def attachDevice(self, xml):
-        disk_info = _parse_disk_info(ElementTree.fromstring(xml))
+        disk_info = _parse_disk_info(etree.fromstring(xml))
         disk_info['_attached'] = True
         self._def['devices']['disks'] += [disk_info]
         return True
 
     def detachDevice(self, xml):
-        disk_info = _parse_disk_info(ElementTree.fromstring(xml))
+        disk_info = _parse_disk_info(etree.fromstring(xml))
         disk_info['_attached'] = True
         return disk_info in self._def['devices']['disks']
 
@@ -404,7 +399,7 @@ class Domain(object):
         self._state = VIR_DOMAIN_RUNNING
 
     def snapshotCreateXML(self, xml, flags):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         name = tree.find('./name').text
         snapshot = DomainSnapshot(name, self)
         self._snapshots[name] = snapshot
@@ -741,7 +736,7 @@ class Connection(object):
 </capabilities>'''
 
     def compareCPU(self, xml, flags):
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
 
         arch_node = tree.find('./arch')
         if arch_node is not None:
diff --git a/nova/tests/test_fakelibvirt.py b/nova/tests/test_fakelibvirt.py
index ac3ceea2d..51ff55b10 100644
--- a/nova/tests/test_fakelibvirt.py
+++ b/nova/tests/test_fakelibvirt.py
@@ -16,7 +16,7 @@
 
 from nova import test
 
-from xml.etree import ElementTree
+from lxml import etree
 
 import fakelibvirt as libvirt
 
@@ -252,7 +252,7 @@ class FakeLibvirtTests(test.TestCase):
         conn.defineXML(get_vm_xml())
         dom = conn.lookupByName('testname')
         xml = dom.XMLDesc(0)
-        ElementTree.fromstring(xml)
+        etree.fromstring(xml)
 
     def _test_accepts_source_type(self, source_type):
         conn = self.get_openAuth_curry_func()('qemu:///system')
@@ -260,7 +260,7 @@ class FakeLibvirtTests(test.TestCase):
         conn.defineXML(get_vm_xml(source_type=source_type))
         dom = conn.lookupByName('testname')
         xml = dom.XMLDesc(0)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         elem = tree.find('./devices/disk/source')
         self.assertEquals(elem.get('file'), '/somefile')
 
@@ -282,7 +282,7 @@ class FakeLibvirtTests(test.TestCase):
         conn.defineXML(get_vm_xml(interface_type=network_type))
         dom = conn.lookupByName('testname')
         xml = dom.XMLDesc(0)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         elem = tree.find('./devices/interface')
         self.assertEquals(elem.get('type'), network_type)
         elem = elem.find('./source')
@@ -298,7 +298,7 @@ class FakeLibvirtTests(test.TestCase):
 
     def test_getCapabilities(self):
         conn = self.get_openAuth_curry_func()('qemu:///system')
-        ElementTree.fromstring(conn.getCapabilities())
+        etree.fromstring(conn.getCapabilities())
 
     def test_nwfilter_define_undefine(self):
         conn = self.get_openAuth_curry_func()('qemu:///system')
diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 61cb2a32a..2343955ba 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -24,7 +24,7 @@ import shutil
 import sys
 import tempfile
 
-from xml.etree import ElementTree
+from lxml import etree
 from xml.dom import minidom
 
 from nova import context
@@ -884,7 +884,7 @@ class LibvirtConnTestCase(test.TestCase):
         conn = connection.LibvirtConnection(True)
         instance_ref = db.instance_create(self.context, instance_data)
         xml = conn.to_xml(instance_ref, network_info, None, False)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         interfaces = tree.findall("./devices/interface")
         self.assertEquals(len(interfaces), 2)
         parameters = interfaces[0].findall('./filterref/parameter')
@@ -906,7 +906,7 @@ class LibvirtConnTestCase(test.TestCase):
 
         network_info = _fake_network_info(self.stubs, 1)
         xml = conn.to_xml(instance_ref, network_info)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
 
         check = [
         (lambda t: t.find('.').get('type'), 'lxc'),
@@ -947,7 +947,7 @@ class LibvirtConnTestCase(test.TestCase):
 
             network_info = _fake_network_info(self.stubs, 1)
             xml = conn.to_xml(instance_ref, network_info)
-            tree = ElementTree.fromstring(xml)
+            tree = etree.fromstring(xml)
 
             for i, (check, expected_result) in enumerate(checks):
                 self.assertEqual(check(tree),
@@ -982,7 +982,7 @@ class LibvirtConnTestCase(test.TestCase):
         xml = connection.LibvirtConnection(True).to_xml(instance_ref,
                                                         network_info,
                                                         image_meta)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         disks = tree.findall('./devices/disk/driver')
         for disk in disks:
             self.assertEqual(disk.get("cache"), "none")
@@ -994,7 +994,7 @@ class LibvirtConnTestCase(test.TestCase):
         xml = connection.LibvirtConnection(True).to_xml(instance_ref,
                                                         network_info,
                                                         image_meta)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         disks = tree.findall('./devices/disk/driver')
         for disk in disks:
             self.assertEqual(disk.get("cache"), "writethrough")
@@ -1007,7 +1007,7 @@ class LibvirtConnTestCase(test.TestCase):
         xml = connection.LibvirtConnection(True).to_xml(instance_ref,
                                                         network_info,
                                                         image_meta)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         self.assertEqual(tree.find('./devices/disk').get('device'),
                          device_type)
         self.assertEqual(tree.find('./devices/disk/target').get('bus'), bus)
@@ -1020,7 +1020,7 @@ class LibvirtConnTestCase(test.TestCase):
         xml = connection.LibvirtConnection(True).to_xml(instance_ref,
                                                         network_info,
                                                         image_meta)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         self.assertEqual(tree.find('./uuid').text,
                          instance_ref['uuid'])
 
@@ -1119,7 +1119,7 @@ class LibvirtConnTestCase(test.TestCase):
 
             network_info = _fake_network_info(self.stubs, 1)
             xml = conn.to_xml(instance_ref, network_info, None, rescue)
-            tree = ElementTree.fromstring(xml)
+            tree = etree.fromstring(xml)
             for i, (check, expected_result) in enumerate(checks):
                 self.assertEqual(check(tree),
                                  expected_result,
@@ -1676,7 +1676,7 @@ class NWFilterFakes:
             def undefine(self):
                 del self.parent.filters[self.name]
                 pass
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
         name = tree.get('name')
         if name not in self.filters:
             self.filters[name] = FakeNWFilterInternal(self, name)
diff --git a/nova/tests/test_libvirt_vif.py b/nova/tests/test_libvirt_vif.py
index 2cc1abcef..dfa18325a 100644
--- a/nova/tests/test_libvirt_vif.py
+++ b/nova/tests/test_libvirt_vif.py
@@ -14,15 +14,15 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from xml.etree import ElementTree
+from lxml import etree
 
 from nova import flags
 from nova import test
 from nova import utils
 from nova.virt import firewall
-from nova.virt.libvirt import vif
-from nova.virt.libvirt import connection
 from nova.virt.libvirt import config
+from nova.virt.libvirt import connection
+from nova.virt.libvirt import vif
 
 FLAGS = flags.FLAGS
 
@@ -83,7 +83,7 @@ class LibvirtVifTestCase(test.TestCase):
         d = vif.LibvirtBridgeDriver()
         xml = self._get_instance_xml(d)
 
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         ret = doc.findall('./devices/interface')
         self.assertEqual(len(ret), 1)
         node = ret[0]
@@ -99,7 +99,7 @@ class LibvirtVifTestCase(test.TestCase):
         d = vif.LibvirtOpenVswitchDriver()
         xml = self._get_instance_xml(d)
 
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         ret = doc.findall('./devices/interface')
         self.assertEqual(len(ret), 1)
         node = ret[0]
@@ -117,7 +117,7 @@ class LibvirtVifTestCase(test.TestCase):
         d = vif.LibvirtOpenVswitchVirtualPortDriver()
         xml = self._get_instance_xml(d)
 
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         ret = doc.findall('./devices/interface')
         self.assertEqual(len(ret), 1)
         node = ret[0]
@@ -143,7 +143,7 @@ class LibvirtVifTestCase(test.TestCase):
         d = vif.QuantumLinuxBridgeVIFDriver()
         xml = self._get_instance_xml(d)
 
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         ret = doc.findall('./devices/interface')
         self.assertEqual(len(ret), 1)
         node = ret[0]
diff --git a/nova/virt/libvirt/connection.py b/nova/virt/libvirt/connection.py
index b8ac5f0f7..234d94afd 100644
--- a/nova/virt/libvirt/connection.py
+++ b/nova/virt/libvirt/connection.py
@@ -39,8 +39,8 @@ Supports KVM, LXC, QEMU, UML, and XEN.
 """
 
 import errno
-import hashlib
 import functools
+import hashlib
 import glob
 import multiprocessing
 import os
@@ -51,9 +51,8 @@ import uuid
 
 from eventlet import greenthread
 from eventlet import tpool
-
+from lxml import etree
 from xml.dom import minidom
-from xml.etree import ElementTree
 
 from nova import block_device
 from nova.compute import instance_types
@@ -528,7 +527,7 @@ class LibvirtConnection(driver.ComputeDriver):
     def _get_disk_xml(xml, device):
         """Returns the xml for the disk mounted at device"""
         try:
-            doc = ElementTree.fromstring(xml)
+            doc = etree.fromstring(xml)
         except Exception:
             return None
         ret = doc.findall('./devices/disk')
@@ -536,7 +535,7 @@ class LibvirtConnection(driver.ComputeDriver):
             for child in node.getchildren():
                 if child.tag == 'target':
                     if child.get('dev') == device:
-                        return ElementTree.tostring(node)
+                        return etree.tostring(node)
 
     @exception.wrap_exception()
     def detach_volume(self, connection_info, instance_name, mountpoint):
@@ -586,7 +585,7 @@ class LibvirtConnection(driver.ComputeDriver):
     @staticmethod
     def get_lxc_container_root(virt_dom):
         xml = virt_dom.XMLDesc(0)
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         filesystem_block = doc.findall('./devices/filesystem')
         for cnt, filesystem_nodes in enumerate(filesystem_block):
             return filesystem_nodes[cnt].get('dir')
@@ -661,7 +660,7 @@ class LibvirtConnection(driver.ComputeDriver):
 
         # Find the disk
         xml_desc = virt_dom.XMLDesc(0)
-        domain = ElementTree.fromstring(xml_desc)
+        domain = etree.fromstring(xml_desc)
         source = domain.find('devices/disk/source')
         disk_path = source.get('file')
 
@@ -946,7 +945,7 @@ class LibvirtConnection(driver.ComputeDriver):
     def get_console_output(self, instance):
         virt_dom = self._lookup_by_name(instance['name'])
         xml = virt_dom.XMLDesc(0)
-        tree = ElementTree.fromstring(xml)
+        tree = etree.fromstring(xml)
 
         console_types = {}
 
@@ -1746,7 +1745,7 @@ class LibvirtConnection(driver.ComputeDriver):
         for dom_id in self._conn.listDomainsID():
             domain = self._conn.lookupByID(dom_id)
             try:
-                doc = ElementTree.fromstring(domain.XMLDesc(0))
+                doc = etree.fromstring(domain.XMLDesc(0))
             except Exception:
                 continue
             ret = doc.findall('./devices/disk')
@@ -1769,7 +1768,7 @@ class LibvirtConnection(driver.ComputeDriver):
         doc = None
 
         try:
-            doc = ElementTree.fromstring(xml)
+            doc = etree.fromstring(xml)
         except Exception:
             return []
 
@@ -1802,7 +1801,7 @@ class LibvirtConnection(driver.ComputeDriver):
         doc = None
 
         try:
-            doc = ElementTree.fromstring(xml)
+            doc = etree.fromstring(xml)
         except Exception:
             return []
 
@@ -1960,7 +1959,7 @@ class LibvirtConnection(driver.ComputeDriver):
         """
 
         xml = self._conn.getCapabilities()
-        xml = ElementTree.fromstring(xml)
+        xml = etree.fromstring(xml)
         nodes = xml.findall('.//host/cpu')
         if len(nodes) != 1:
             reason = _("'<cpu>' must be 1, but %d\n") % len(nodes)
@@ -2363,7 +2362,7 @@ class LibvirtConnection(driver.ComputeDriver):
 
         virt_dom = self._lookup_by_name(instance_name)
         xml = virt_dom.XMLDesc(0)
-        doc = ElementTree.fromstring(xml)
+        doc = etree.fromstring(xml)
         disk_nodes = doc.findall('.//devices/disk')
         path_nodes = doc.findall('.//devices/disk/source')
         driver_nodes = doc.findall('.//devices/disk/driver')
diff --git a/nova/volume/san.py b/nova/volume/san.py
index 1d5a36057..aecb9a0b5 100644
--- a/nova/volume/san.py
+++ b/nova/volume/san.py
@@ -30,7 +30,8 @@ import random
 import socket
 import string
 import uuid
-from xml.etree import ElementTree
+
+from lxml import etree
 
 from nova import exception
 from nova import flags
@@ -145,7 +146,7 @@ class SanISCSIDriver(nova.volume.driver.ISCSIDriver):
         pass
 
     def check_for_setup_error(self):
-        """Returns an error if prerequisites aren't met"""
+        """Returns an error if prerequisites aren't met."""
         if not self.run_local:
             if not (FLAGS.san_password or FLAGS.san_private_key):
                 raise exception.Error(_('Specify san_password or '
@@ -451,7 +452,7 @@ class HpSanISCSIDriver(SanISCSIDriver):
 
         LOG.debug(_("CLIQ command returned %s"), out)
 
-        result_xml = ElementTree.fromstring(out)
+        result_xml = etree.fromstring(out)
         if check_cliq_result:
             response_node = result_xml.find("response")
             if response_node is None:
@@ -492,7 +493,7 @@ class HpSanISCSIDriver(SanISCSIDriver):
         if len(vips) == 1:
             return vips[0]
 
-        _xml = ElementTree.tostring(cluster_xml)
+        _xml = etree.tostring(cluster_xml)
         msg = (_("Unexpected number of virtual ips for cluster "
                  " %(cluster_name)s. Result=%(_xml)s") %
                locals())