mirror of
https://github.com/retspen/webvirtcloud
synced 2026-11-10 12:16:49 +00:00
fix(instances): clones roll back their copies; own error messages stay
Clone: - only shut-off VMs are cloned, as the UI already required: a running guest keeps writing while its disks are copied; the definition comes from the persistent XML; - MAC addresses and disk destinations are checked before anything is allocated; - every volume the clone creates (NVRAM and disks) is tracked; if a later copy or the definition fails, only those are deleted, and any that cannot be deleted are named in the error. Before, a failed clone left its earlier copies behind. libvirtError(msg) reports the thread's last libvirt error instead of msg when there is one, so WebVirtCloud's own errors could show an earlier, unrelated failure. util.OperationError, a libvirtError subclass that keeps its message, replaces those raises in vrtManager, instances and nwfilters; 'except libvirtError' still catches it.
This commit is contained in:
catborise
parent
e5fda79f5a
commit
57cf49262a
8 changed files with 282 additions and 139 deletions
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@ -301,7 +301,7 @@ class wvmConnectionManager(object):
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return connection.connection
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else:
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# raise libvirt error
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raise libvirtError(connection.last_error)
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raise util.OperationError(connection.last_error)
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def host_is_up(self, conn_type, hostname):
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"""
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@ -140,7 +140,7 @@ class wvmInstances(wvmConnect):
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dom_emulator = conn.get_dom_emulator()
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if dom_emulator != self.get_emulator(dom_arch):
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raise libvirtError(
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raise util.OperationError(
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"Destination host emulator is different. Cannot be migrated"
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)
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@ -721,7 +721,7 @@ class wvmInstance(wvmConnect):
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tree = etree.fromstring(self._XMLDesc(xml_flags))
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found = tree.xpath("./devices/disk[@device='cdrom'][target/@dev=$dev]", dev=dev)
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if not found:
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raise libvirtError(f"CD-ROM {dev} is not in the {label} definition")
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raise util.OperationError(f"CD-ROM {dev} is not in the {label} definition")
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devices.append(found[0])
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for (label, _, affect), disk in zip(definitions, devices):
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for source in disk.findall("source"):
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@ -732,7 +732,7 @@ class wvmInstance(wvmConnect):
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self.instance.updateDeviceFlags(etree.tostring(disk).decode(), affect)
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except libvirtError as err:
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if label == "persistent" and len(definitions) == 2:
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raise libvirtError(f"Media of {dev} changed in the running VM only: {err}") from err
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raise util.OperationError(f"Media of {dev} changed in the running VM only: {err}") from err
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raise
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def mount_iso(self, dev, image):
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@ -742,9 +742,9 @@ class wvmInstance(wvmConnect):
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if image in stg.listVolumes():
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paths.append(stg.storageVolLookupByName(image).path())
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if not paths:
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raise libvirtError(f"ISO image {image} was not found")
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raise util.OperationError(f"ISO image {image} was not found")
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if len(paths) > 1:
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raise libvirtError(f"ISO image {image} is in more than one storage pool")
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raise util.OperationError(f"ISO image {image} is in more than one storage pool")
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self._set_cdrom_media(dev, paths[0])
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def umount_iso(self, dev, image=None):
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@ -986,7 +986,7 @@ class wvmInstance(wvmConnect):
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parent.remove(vcpu)
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self._defineXML(etree.tostring(tree).decode())
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else:
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raise libvirtError(
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raise util.OperationError(
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"Please shutdown the instance then try to enable vCPU hotplug"
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)
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@ -1505,26 +1505,29 @@ class wvmInstance(wvmConnect):
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return ":".join(mac_tuples)
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def clone_instance(self, clone_data):
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clone_dev_path = []
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"""Copy a shut-off VM. Inputs are checked before anything is allocated,
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and on failure only the volumes this call created are removed (R-08)."""
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if self.get_status() != 5:
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# A running guest keeps writing while its disks are copied.
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raise util.OperationError("Shut the VM down before cloning it")
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if clone_data["name"] in self.get_instances():
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raise ValueError("An instance with the clone name already exists")
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xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
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tree = etree.fromstring(xml)
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name = tree.find("name")
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name.text = clone_data["name"]
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tree = etree.fromstring(self._XMLDesc(PERSISTENT_XML))
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tree.find("name").text = clone_data["name"]
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uuid = tree.find("uuid")
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if uuid is None:
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uuid = etree.SubElement(tree, "uuid")
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uuid.text = util.randomUUID()
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self._set_options(
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tree,
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{
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"title": clone_data.get("clone-title", ""),
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"description": clone_data.get("clone-description", ""),
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},
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)
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options = {
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"title": clone_data.get("clone-title", ""),
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"description": clone_data.get("clone-description", ""),
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}
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self._set_options(tree, options)
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disks = []
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for disk in list(tree.findall("devices/disk")):
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if disk.get("device") != "disk":
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continue
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@ -1539,120 +1542,96 @@ class wvmInstance(wvmConnect):
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dev = target.get("dev") if target is not None else None
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if not supported or not dev or not clone_data.get("disk-" + dev):
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raise ValueError("Cannot clone a disk without a supported source and destination")
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src_nvram_path = self.get_nvram()
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if src_nvram_path:
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# Change XML for nvram
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nvram = tree.find("os/nvram")
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nvram.getparent().remove(nvram)
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# NVRAM CLONE: create pool if nvram is not in a pool. then clone it
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src_nvram_name = os.path.basename(src_nvram_path)
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nvram_dir = os.path.dirname(src_nvram_path)
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nvram_pool_name = os.path.basename(nvram_dir)
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try:
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self.get_volume_by_path(src_nvram_path)
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except libvirtError:
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stg_conn = self.get_wvmStorages()
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stg_conn.create_storage("dir", nvram_pool_name, None, nvram_dir)
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new_nvram_name = f"{clone_data['name']}_VARS"
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nvram_stg = self.get_wvmStorage(nvram_pool_name)
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nvram_stg.clone_volume(src_nvram_name, new_nvram_name, file_suffix="fd")
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disks.append((source, dev))
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for num, net in enumerate(tree.findall("devices/interface")):
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elm = net.find("mac")
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mac_address = self.fix_mac(clone_data["clone-net-mac-" + str(num)])
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elm.set("address", mac_address)
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mac = clone_data.get(f"clone-net-mac-{num}")
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if not mac:
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raise ValueError(f"No MAC address for network interface {num}")
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net.find("mac").set("address", self.fix_mac(mac))
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for disk in tree.findall("devices/disk"):
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if disk.get("device") == "disk":
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elm = disk.find("target")
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device_name = elm.get("dev")
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if device_name:
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target_file = clone_data["disk-" + device_name]
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meta_prealloc = False
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with contextlib.suppress(Exception):
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meta_prealloc = clone_data["meta-" + device_name]
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created = [] # paths of volumes this call created
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try:
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src_nvram_path = self.get_nvram()
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if src_nvram_path:
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nvram = tree.find("os/nvram")
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nvram.getparent().remove(nvram)
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elm.set("dev", device_name)
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# NVRAM CLONE: create pool if nvram is not in a pool. then clone it
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src_nvram_name = os.path.basename(src_nvram_path)
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nvram_dir = os.path.dirname(src_nvram_path)
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nvram_pool_name = os.path.basename(nvram_dir)
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try:
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self.get_volume_by_path(src_nvram_path)
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except libvirtError:
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self.get_wvmStorages().create_storage("dir", nvram_pool_name, None, nvram_dir)
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nvram_stg = self.get_wvmStorage(nvram_pool_name)
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name = nvram_stg.clone_volume(src_nvram_name, f"{clone_data['name']}_VARS", file_suffix="fd")
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created.append(os.path.join(nvram_dir, name))
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elm = disk.find("source")
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source_file = elm.get("file")
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if source_file:
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clone_dev_path.append(source_file)
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clone_path = os.path.join(os.path.dirname(source_file), target_file)
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elm.set("file", clone_path)
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vol = self.get_volume_by_path(source_file)
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vol_format = util.get_xml_path(
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vol.XMLDesc(0), "/volume/target/format/@type"
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for source, dev in disks:
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target_file = clone_data["disk-" + dev]
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meta_prealloc = bool(clone_data.get("meta-" + dev))
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if source.get("file"):
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vol = self.get_volume_by_path(source.get("file"))
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vol_format = util.get_xml_path(vol.XMLDesc(0), "/volume/target/format/@type")
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new_vol = vol.storagePoolLookupByVolume().createXMLFrom(
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f"""<volume>
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<name>{target_file}</name>
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<capacity>0</capacity>
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<allocation>0</allocation>
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<target>
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<format type='{vol_format}'/>
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<permissions>
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<owner>{clone_data['disk_owner_uid']}</owner>
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<group>{clone_data['disk_owner_gid']}</group>
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<mode>0644</mode>
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<label>virt_image_t</label>
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</permissions>
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<compat>1.1</compat>
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<features><lazy_refcounts/></features>
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</target>
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</volume>""",
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vol,
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meta_prealloc and vol_format == "qcow2",
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)
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if vol_format == "qcow2" and meta_prealloc:
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meta_prealloc = True
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vol_clone_xml = f"""
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<volume>
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<name>{target_file}</name>
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<capacity>0</capacity>
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<allocation>0</allocation>
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<target>
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<format type='{vol_format}'/>
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<permissions>
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<owner>{clone_data['disk_owner_uid']}</owner>
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<group>{clone_data['disk_owner_gid']}</group>
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<mode>0644</mode>
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<label>virt_image_t</label>
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</permissions>
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<compat>1.1</compat>
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<features>
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<lazy_refcounts/>
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</features>
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</target>
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</volume>"""
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stg = vol.storagePoolLookupByVolume()
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stg.createXMLFrom(vol_clone_xml, vol, meta_prealloc)
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source_protocol = elm.get("protocol")
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if source_protocol == "rbd":
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source_name = elm.get("name")
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clone_name = "%s/%s" % (os.path.dirname(source_name), target_file)
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elm.set("name", clone_name)
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vol = self.get_volume_by_path(source_name)
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vol_format = util.get_xml_path(
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vol.XMLDesc(0), "/volume/target/format/@type"
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created.append(new_vol.path())
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source.set("file", new_vol.path())
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elif source.get("protocol") == "rbd":
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vol = self.get_volume_by_path(source.get("name"))
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vol_format = util.get_xml_path(vol.XMLDesc(0), "/volume/target/format/@type")
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new_vol = vol.storagePoolLookupByVolume().createXMLFrom(
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f"""<volume type='network'>
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<name>{target_file}</name>
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<capacity>0</capacity>
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<allocation>0</allocation>
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<target><format type='{vol_format}'/></target>
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</volume>""",
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vol,
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meta_prealloc,
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)
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vol_clone_xml = f"""
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<volume type='network'>
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<name>{target_file}</name>
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<capacity>0</capacity>
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<allocation>0</allocation>
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<target>
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<format type='{vol_format}'/>
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</target>
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</volume>"""
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stg = vol.storagePoolLookupByVolume()
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stg.createXMLFrom(vol_clone_xml, vol, meta_prealloc)
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source_dev = elm.get("dev")
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if source_dev:
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clone_path = os.path.join(os.path.dirname(source_dev), target_file)
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elm.set("dev", clone_path)
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vol = self.get_volume_by_path(source_dev)
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stg = vol.storagePoolLookupByVolume()
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vol_name = util.get_xml_path(vol.XMLDesc(0), "/volume/name")
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pool_name = util.get_xml_path(stg.XMLDesc(0), "/pool/name")
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created.append(new_vol.path())
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source.set("name", f"{os.path.dirname(source.get('name'))}/{target_file}")
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else:
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vol = self.get_volume_by_path(source.get("dev"))
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pool_name = util.get_xml_path(vol.storagePoolLookupByVolume().XMLDesc(0), "/pool/name")
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storage = self.get_wvmStorage(pool_name)
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storage.clone_volume(vol_name, target_file)
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name = storage.clone_volume(vol.name(), target_file)
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new_path = storage.get_volume(name).path()
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created.append(new_path)
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source.set("dev", new_path)
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self._defineXML(ElementTree.tostring(tree).decode())
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self._defineXML(etree.tostring(tree).decode())
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except Exception as err:
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leftovers = []
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for path in reversed(created):
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try:
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self.get_volume_by_path(path).delete(0)
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except libvirtError:
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leftovers.append(path)
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if leftovers:
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raise util.OperationError(f"Clone failed ({err}); remove these copies by hand: {', '.join(leftovers)}") from err
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raise
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return self.get_instance(clone_data["name"]).UUIDString()
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@ -1720,7 +1699,7 @@ class wvmInstance(wvmConnect):
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"""Replace the NIC with old_mac; put it back if the new one cannot be added."""
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old_xml = self.delete_network(old_mac)
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if old_xml is None:
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raise libvirtError(f"No network interface with MAC {old_mac}")
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raise util.OperationError(f"No network interface with MAC {old_mac}")
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try:
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self.add_network(mac, source, source_type, model, nwfilter)
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except libvirtError:
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@ -1757,11 +1736,11 @@ class wvmInstance(wvmConnect):
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elif net_source_type == "iface":
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source.set("dev", net_source)
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else:
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raise libvirtError(
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raise util.OperationError(
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"Unknown network type: {}".format(net_source_type)
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)
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else:
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raise libvirtError(
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raise util.OperationError(
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"Unknown network type: {}".format(interface.get("type"))
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)
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@ -128,5 +128,21 @@ class TestVrtManagerUtil(unittest.TestCase):
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self.assertIsNone(vol_dev_type("unknown_bus"))
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class OperationErrorTestCase(unittest.TestCase):
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def test_keeps_its_own_message_after_a_libvirt_failure(self):
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import libvirt
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from vrtManager.util import OperationError
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conn = libvirt.open("test:///default")
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self.addCleanup(conn.close)
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with self.assertRaises(libvirt.libvirtError):
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conn.lookupByName("no-such-domain") # leaves a thread-local last error
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self.assertNotEqual(str(libvirt.libvirtError("own message")), "own message")
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error = OperationError("own message")
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self.assertEqual(str(error), "own message")
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self.assertIsInstance(error, libvirt.libvirtError)
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if __name__ == "__main__":
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unittest.main()
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@ -185,6 +185,47 @@ class TestXmlSafety(unittest.TestCase):
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self.assertIn("type='pflash'", inst._snapshotCreateXML.call_args[0][0])
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class TestCloneRollback(unittest.TestCase):
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"""R-08: a failed clone removes only the volumes it created."""
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def test_copies_are_removed_when_the_definition_fails(self):
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import libvirt
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inst = wvmInstance.__new__(wvmInstance)
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inst.wvm = MagicMock()
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inst.get_status = MagicMock(return_value=5)
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inst.get_instances = MagicMock(return_value=[])
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inst.get_nvram = MagicMock(return_value=None)
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inst._XMLDesc = MagicMock(return_value=(
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"<domain><name>src</name><devices>"
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"<disk type='file' device='disk'><source file='/pool/src.qcow2'/><target dev='vda'/></disk>"
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"</devices></domain>"
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))
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source_vol = MagicMock()
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source_vol.XMLDesc.return_value = "<volume><target><format type='qcow2'/></target></volume>"
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copy = MagicMock()
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copy.path.return_value = "/pool/copy.qcow2"
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source_vol.storagePoolLookupByVolume.return_value.createXMLFrom.return_value = copy
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inst.get_volume_by_path = MagicMock(side_effect=lambda path: copy if path == "/pool/copy.qcow2" else source_vol)
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inst._defineXML = MagicMock(side_effect=libvirt.libvirtError("bad definition"))
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with self.assertRaises(libvirt.libvirtError):
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inst.clone_instance({"name": "copy", "disk-vda": "copy.qcow2", "disk_owner_uid": 0, "disk_owner_gid": 0})
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copy.delete.assert_called_once_with(0)
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source_vol.delete.assert_not_called()
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def test_running_vm_is_refused_before_anything_is_read(self):
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import libvirt
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inst = wvmInstance.__new__(wvmInstance)
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inst.get_status = MagicMock(return_value=1)
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inst._XMLDesc = MagicMock()
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with self.assertRaisesRegex(libvirt.libvirtError, "Shut the VM down"):
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inst.clone_instance({"name": "copy"})
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inst._XMLDesc.assert_not_called()
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if __name__ == "__main__":
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unittest.main()
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@ -379,6 +420,7 @@ class TestEmptyDiskClone(unittest.TestCase):
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# Exercise defensive handling of incomplete disk metadata, while the
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# clone is still defined and looked up through the real test driver.
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inst._XMLDesc = MagicMock(return_value=etree.tostring(config).decode())
|
||||
inst.get_status = MagicMock(return_value=5) # only shut-off VMs are cloned
|
||||
clone_uuid = inst.clone_instance({"name": "empty-disk-clone"})
|
||||
clone = conn.lookupByUUIDString(clone_uuid)
|
||||
self.addCleanup(clone.undefine)
|
||||
|
|
@ -396,6 +438,7 @@ class TestEmptyDiskClone(unittest.TestCase):
|
|||
inst.wvm = conn
|
||||
inst.instance = conn.lookupByName("test")
|
||||
inst._XMLDesc = MagicMock()
|
||||
inst.get_status = MagicMock(return_value=5)
|
||||
with self.assertRaisesRegex(ValueError, "already exists"):
|
||||
inst.clone_instance({"name": "test"})
|
||||
inst._XMLDesc.assert_not_called()
|
||||
|
|
|
|||
|
|
@ -9,6 +9,19 @@ import lxml.etree as etree
|
|||
from django.conf import settings
|
||||
|
||||
|
||||
|
||||
class OperationError(libvirt.libvirtError):
|
||||
"""An error with WebVirtCloud's own message.
|
||||
|
||||
libvirtError(msg) reports the thread's last libvirt error instead of msg
|
||||
when there is one, so an earlier, unrelated failure would be shown.
|
||||
"""
|
||||
|
||||
def __init__(self, msg):
|
||||
Exception.__init__(self, msg)
|
||||
self.err = None
|
||||
|
||||
|
||||
def is_kvm_available(xml):
|
||||
kvm_domains = get_xml_path(xml, "//domain/@type='kvm'")
|
||||
return kvm_domains > 0
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue