From: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>

This patch adds the CREATE, LOOKUP, UPDATE and DELETE functionalities
to guest storage devices support.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>

Using lxml and objectify to parse the XML info.
Pep8 adjustments in model/vms.py

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
---
 src/kimchi/model/vms.py | 184 ++++++++++++++++++++++++++++++++++++++++++++++--
 src/kimchi/xmlutils.py  |   5 ++
 2 files changed, 185 insertions(+), 4 deletions(-)

diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index 1244eeb..3c2a661 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -20,13 +20,17 @@
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA

+import libvirt
 import os
+import socket
+import string
 import time
+import urlparse
 import uuid
-from xml.etree import ElementTree

-import libvirt
 from cherrypy.process.plugins import BackgroundTask
+from lxml import etree, objectify
+from xml.etree import ElementTree

 from kimchi import vnc
 from kimchi import xmlutils
@@ -36,7 +40,8 @@ from kimchi.model.config import CapabilitiesModel
 from kimchi.model.templates import TemplateModel
 from kimchi.model.utils import get_vm_name
 from kimchi.screenshot import VMScreenshot
-from kimchi.utils import run_setfacl_set_attr, template_name_from_uri
+from kimchi.utils import kimchi_log, run_setfacl_set_attr
+from kimchi.utils import template_name_from_uri


 DOM_STATE_MAP = {0: 'nostate',
@@ -47,6 +52,10 @@ DOM_STATE_MAP = {0: 'nostate',
                  5: 'shutoff',
                  6: 'crashed'}

+DEV_TYPE_SRC_ATTR_MAP = {'file': 'file',
+                         'block': 'dev',
+                         'dir': 'dir'}
+
 GUESTS_STATS_INTERVAL = 5
 VM_STATIC_UPDATE_PARAMS = {'name': './name'}
 VM_LIVE_UPDATE_PARAMS = {}
@@ -222,7 +231,7 @@ class VMModel(object):
         dom = self.get_vm(name, self.conn)
         dom = self._static_vm_update(dom, params)
         self._live_vm_update(dom, params)
-        return dom.name().decode('utf-8')
+        return dom.name()

     def _static_vm_update(self, dom, params):
         state = DOM_STATE_MAP[dom.info()[0]]
@@ -453,3 +462,170 @@ class LibvirtVMScreenshot(VMScreenshot):
             stream.finish()
         finally:
             os.close(fd)
+
+
+class StoragesModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+
+    def _get_storage_xml(self, params):
+        storage = """
+            <disk type='%(src_type)s' device='%(dev_type)s'>
+              <driver name='qemu' type='raw'/>%(source)s
+              <target dev='%(dev)s' bus='ide'/>
+            </disk>
+        """

+        info = {}
+        info['dev'] = params.get('dev')
+        info['dev_type'] = params.get('type')
+        info['src_type'] = params.get('src_type')
+
+        # Working with url paths
+        if info['src_type'] == 'network':
+            net = {}
+            output = urlparse.urlparse(params.get('path'))
+            net['protocol'] = output.scheme
+            net['port'] = output.port or socket.getservbyname(output.scheme)
+            net['hostname'] = output.hostname
+            net['url_path'] = output.path
+            info['source'] = """
+              <source protocol='%(protocol)s' name='%(url_path)s'>
+                <host name='%(hostname)s' port='%(port)s'/>
+              </source>""" % net

+        else:
+            # Fixing source attribute
+            info['source'] = """
+               <source %s='%s'/>""" % (DEV_TYPE_SRC_ATTR_MAP[info['src_type']],
+                                       params.get('path'))
+        return storage % info
+
+    def create(self, vm_name, params):
+        #TODO: Check if device name is already use
+        path = params.get('path')
+
+        # Checking if path exist, if not url
+        if path.startswith('/'):
+            if not os.path.exists(path):
+                msg = "Path specified for device is not valid"
+                raise InvalidParameter(msg)
+            elif path.endswith('.iso') or os.path.isfile(path):
+                params['src_type'] = 'file'
+            elif os.path.isdir(path):
+                params['src_type'] = 'dir'

http://wiki.qemu.org/download/qemu-doc.html#disk_005fimages_005ffat_005fimages
http://en.wikibooks.org/wiki/QEMU/Devices/Storage
'dir' type is used to share directory between host(linux) and guest(windows) without using samba or nfs, or create a boot floppy.
So I don't think its related to CDROM management and will cause unexpected result. Let's get rid of it temporarily until we start to support this feature.

+            else:
+                params['src_type'] = 'block'

+        else:
+            params['src_type'] = 'network'

+
+        # Use device name passed or pick next
+        dev_name = params.get('dev')
+        if not dev_name:
+            params['dev'] = self._get_storage_device_name(vm_name)
+
+        # Add device to VM
+        dev_xml = self._get_storage_xml(params)
+        try:
+            conn = self.conn.get()
+            dom = conn.lookupByName(vm_name)
+            dom.attachDeviceFlags(dev_xml, libvirt.VIR_DOMAIN_AFFECT_CURRENT)
+        except Exception as e:
+            msg = 'Was not possible to attach storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
+        return params['dev']
+
+    def _get_storage_device_name(self, vm_name):
+        dev_list = [dev for dev in self.get_list(vm_name)
+                    if dev.startswith('hd')]
+        if len(dev_list) == 0:
+            return 'hda'
+        dev_list.sort()
+        last_dev = dev_list.pop()
+        # TODO: Improve to device names "greater then" hdz
+        next_dev_letter_pos = string.ascii_lowercase.index(last_dev[2]) + 1
+        return 'hd' + string.ascii_lowercase[next_dev_letter_pos]
+
+    def get_list(self, vm_name):
+        dom = VMModel.get_vm(vm_name, self.conn)
+        xml = dom.XMLDesc(0)
+        devices = objectify.fromstring(xml).devices
+        storages = [disk.target.attrib['dev']
+                    for disk in devices.xpath("./disk[@device='disk']")]
+        storages += [disk.target.attrib['dev']
+                     for disk in devices.xpath("./disk[@device='cdrom']")]
+        return storages
+
+
+class StorageModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+        self.kargs = kargs
+
+    def _get_device_xml(self, vm_name, dev_name):
+        # Get VM xml and then devices xml
+        dom = VMModel.get_vm(vm_name, self.conn)
+        xml = dom.XMLDesc(0)
+        devices = objectify.fromstring(xml).devices
+        disk = devices.xpath("./disk/target[@dev='%s']/.." % dev_name)
+        return disk[0]
+
+    def lookup(self, vm_name, dev_name):
+        # Retrieve disk xml and format return dict
+        disk = self._get_device_xml(vm_name, dev_name)
+        if disk is None:
+            raise NotFoundError('The storage device "%s" does not exist in '
+                                'the guest "%s"' % (dev_name, vm_name))
+        source = disk.source
+        path = ""
+        if source is not None:
+            src_type = disk.attrib['type']
+            if src_type == 'network':
+                host = source.host
+                path = (source.attrib['protocol'] + '://' +
+                        host.attrib['name'] + ':' +
+                        host.attrib['port'] + source.attrib['name'])
+            else:
+                path = source.attrib[DEV_TYPE_SRC_ATTR_MAP[src_type]]
+        dev_type = disk.attrib['device']
+        return {'dev': dev_name,
+                'type': dev_type,
+                'path': path}
+
+    def delete(self, vm_name, dev_name):
+        # Get storage device xml
+        disk = self._get_device_xml(vm_name, dev_name)
+        if disk is None:
+            raise NotFoundError('The storage device "%s" does not exist in '
+                                'the guest "%s"' % (dev_name, vm_name))
+        try:
+            conn = self.conn.get()
+            dom = conn.lookupByName(vm_name)
+            dom.detachDeviceFlags(etree.tostring(disk),
+                                  libvirt.VIR_DOMAIN_AFFECT_CURRENT)
+        except Exception as e:
+            msg = 'Was not possible to detach storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
+
+    def update(self, vm_name, dev_name, params):
+        info = self.lookup(vm_name, dev_name)
+        backup_params = info.copy()
+        try:
+            self.delete(vm_name, dev_name)
+        except:
+            msg = 'Was not possible to update storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
+
+        info.update(params)
+        kargs = {'conn': self.conn}
+        stgModel = StoragesModel(**kargs)
+        try:
+            dev_name = stgModel.create(vm_name, info)
+            return dev_name
+        except Exception as e:
+            # Restoring previous device
+            dev_name = stgModel.create(vm_name, backup_params)
+            msg = 'Was not possible to update storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
diff --git a/src/kimchi/xmlutils.py b/src/kimchi/xmlutils.py
index 51ff0ec..176ceb1 100644
--- a/src/kimchi/xmlutils.py
+++ b/src/kimchi/xmlutils.py
@@ -40,3 +40,8 @@ def xml_item_update(xml, xpath, value):
     item = root.find(xpath)
     item.text = value
     return ElementTree.tostring(root, encoding="utf-8")
+
+def xml_get_child(xml, xpath):
+    root = ElementTree.fromstring(xml)
+    item = root.find(xpath)
+    return ElementTree.tostring(item, encoding="utf-8")