[Kimchi-devel] [PATCH v3 3/4] CDROM Management: Devices management model implementation
Daniel H Barboza
danielhb at linux.vnet.ibm.com
Wed Feb 12 17:32:01 UTC 2014
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 :)
>> + 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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