[Kimchi-devel] [PATCH v3 3/4] CDROM Management: Devices management model implementation
Aline Manera
alinefm at linux.vnet.ibm.com
Wed Feb 12 18:02:41 UTC 2014
On 02/12/2014 03:32 PM, Daniel H Barboza wrote:
>
> On 02/12/2014 07:08 AM, Royce Lv wrote:
>> On 2014?02?12? 10:38, Daniel Barboza wrote:
>>> From: Rodrigo Trujillo<rodrigo.trujillo at 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 at 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 at 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>
>>> + """
>> To keep consistency, may I suggest we use lxml.builder and lxml etree.
>>> + 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
>> Here too.
> I tried, but couldn't came up with a code using lxml.builder and/or
> objectify which is simpler
> and more readable than this one.
>
> If anyone wants to jump in and provide such code, please do :)
>
import lxml.etree as ET
from lxml.builder import E
host = E.host()
host.set('name', 'localhost')
host.set('port', '80')
source = E.source(host)
source.set('protocol', 'http')
source.set('name', '/my-iso.iso')
print ET.tostring(source)
>
>>> + 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'
>> REF:
>> 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'
>> Does it mean other type is classified to block? I think only block
>> device should be used. Also I suggest we only suggest the same
>> usecase with template cdrom, that is file or valid file link,
>> The use of host block device may be out of our scope.
>>> + else:
>>> + params['src_type'] = 'network'
>> Will it be better if we validate the source file as we did in osinfo.py?
>> response = urllib2.urlopen(request)
>> data = response.read()
>>> +
>>> + # 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")
>>
>
>
>
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