[Kimchi-devel] [PATCH v5 3/5] CDROM Management: Devices management model implementation
Royce Lv
lvroyce at linux.vnet.ibm.com
Fri Feb 14 08:47:37 UTC 2014
On 2014年02月14日 09:45, 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
> Removing hard disk support from model/vms.py
> Including xml creation using lxml in _get_storage_xml
> Including existing device name verification
> Changed model/vms.py to use the new exception model.
>
> Signed-off-by: Daniel Henrique Barboza <danielhb at linux.vnet.ibm.com>
> ---
> src/kimchi/model/vms.py | 173 +++++++++++++++++++++++++++++++++++++++++++++++-
> src/kimchi/xmlutils.py | 2 +-
> 2 files changed, 172 insertions(+), 3 deletions(-)
>
> diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
> index 2585082..6774c7e 100644
> --- a/src/kimchi/model/vms.py
> +++ b/src/kimchi/model/vms.py
> @@ -21,12 +21,18 @@
> # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>
> import os
> +import socket
> +import string
> import time
> +import urlparse
> import uuid
> from xml.etree import ElementTree
>
> import libvirt
> +import lxml.etree as ET
> from cherrypy.process.plugins import BackgroundTask
> +from lxml import etree, objectify
> +from lxml.builder import E
>
> from kimchi import vnc
> from kimchi import xmlutils
> @@ -36,7 +42,8 @@ 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 check_url_path, kimchi_log, run_setfacl_set_attr
> +from kimchi.utils import template_name_from_uri
>
>
> DOM_STATE_MAP = {0: 'nostate',
> @@ -47,6 +54,10 @@ DOM_STATE_MAP = {0: 'nostate',
> 5: 'shutoff',
> 6: 'crashed'}
>
> +DEV_TYPE_SRC_ATTR_MAP = {'file': 'file',
> + 'block': 'dev',
> + 'dir': 'dir'}
'dir' source type still here.
> +
> GUESTS_STATS_INTERVAL = 5
> VM_STATIC_UPDATE_PARAMS = {'name': './name'}
> VM_LIVE_UPDATE_PARAMS = {}
> @@ -243,7 +254,7 @@ 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]]
> @@ -474,3 +485,161 @@ 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):
> + src_type = params.get('src_type')
> + disk = E.disk(type=src_type, device=params.get('type'))
> + disk.append(E.driver(name='qemu', type='raw'))
> + # Working with url paths
> + if src_type == 'network':
> + output = urlparse.urlparse(params.get('path'))
> + host = E.host(name=output.hostname, port=
> + output.port or socket.getservbyname(output.scheme))
> + source = E.source(protocol=output.scheme, name=output.path)
> + source.append(host)
> + disk.append(source)
> + else:
> + # Fixing source attribute
> + source = E.source()
> + source.set(DEV_TYPE_SRC_ATTR_MAP[src_type], params.get('path'))
> + disk.append(source)
> +
> + disk.append(E.target(dev=params.get('dev'), bus='ide'))
> + return ET.tostring(disk)
> +
> + def create(self, vm_name, params):
> + # 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)
> + else:
> + devices = self.get_list(vm_name)
> + if dev_name in devices:
> + raise OperationFailed("KCHCDROM0004E",
> + {'dev_name': dev_name,
> + 'vm_name': vm_name})
> +
> + # Path will never be blank due to API.json verification.
> + # There is no need to cover this case here.
> + path = params.get('path')
> +
> + # Checking if path exist, if not url
> + if os.path.exists(path):
> + if os.path.isfile(path):
> + params['src_type'] = 'file'
> + elif os.path.isdir(path):
> + raise InvalidParameter("KCHCDROM0006E")
> + else:
> + params['src_type'] = 'block'
At least we need to make sure it is a block device, and we need to limit
the block device we want to expose. I'm worried about there will be data
corruption if we expose all.
> + elif check_url_path(path):
> + params['src_type'] = network
> + else:
> + raise InvalidParameter("KCHCDROM0005E", {'path': path})
> +
> + # Add device to VM
> + dev_xml = self._get_storage_xml(params)
> + try:
CDROM is IDE device, which does not allow hotplug, so pls only allow
device update when vm is shutoff.
> + conn = self.conn.get()
> + dom = conn.lookupByName(vm_name)
> + dom.attachDeviceFlags(dev_xml, libvirt.VIR_DOMAIN_AFFECT_CURRENT)
> + except Exception as e:
> + raise OperationFailed("KCHCDROM0011E", {'error': 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)
> + if not disk:
> + return None
> + 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("KCHCDROM0007E", {'dev_name': dev_name,
> + 'vm_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("KCHCDROM0007E",
> + {'dev_name': dev_name,
> + 'vm_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:
> + raise OperationFailed("KCHCDROM0010E", {'error': 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 Exception as e:
> + raise OperationFailed("KCHCDROM0009E", {'error': 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)
> + raise OperationFailed("KCHCDROM0009E", {'error': e.message})
> diff --git a/src/kimchi/xmlutils.py b/src/kimchi/xmlutils.py
> index 51ff0ec..44facbd 100644
> --- a/src/kimchi/xmlutils.py
> +++ b/src/kimchi/xmlutils.py
> @@ -29,7 +29,7 @@ from xml.etree import ElementTree
> def xpath_get_text(xml, expr):
> doc = libxml2.parseDoc(xml)
> res = doc.xpathEval(expr)
> - ret = [None if x.children == None else x.children.content for x in res]
> + ret = [None if x.children is None else x.children.content for x in res]
>
> doc.freeDoc()
> return ret
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