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webvirtcloud/instances/utils.py
catborise 400ba1614f feat(instances): a VM's clone form in device cards, with fixes to what it clones
Settings > Clone was a horizontal form with unlabelled checkboxes. The
owner chose this layout from three rendered options: the clone's name
on top, a "Network" card with a new MAC address per NIC, a "Storage"
card with a new volume name per disk, then the optional title and
description and a footer with Clone.

Codex reviewed cloning end to end; these are fixed:

- Every NIC of the clone gets a new random MAC when the form opens.
  Only the first did, so a VM with two NICs gave its clone the second
  NIC's MAC. Guess MAC is offered for the first NIC only: a name's DHCP
  host entry holds one address.
- A VM without a NIC can be cloned: the first NIC's MAC was required.
- The disk name script uses the persistent disks, as the form does; a
  disk added pending the next start kept the source's volume name.
- A running or paused VM is not cloned while a copied disk changes at
  the next start: the backup copies the running disk, so the clone
  would get the old contents under the new definition.
- A derived volume name that does not start with the source's name now
  starts with the clone's name and the disk's device, so a second clone
  or a second disk does not take the same name.
- Guess for the clone name says when the DHCP file has no free name; it
  stopped with a script error.
- The qcow2 metadata preallocation box shows only for a shut-off VM: a
  live clone's backup ignores it.

Other users no longer get hidden MAC and disk inputs or the scripts that
filled them: the server derives those values and ignored the posted ones.
2026-10-30 14:55:57 +03:00

395 lines
14 KiB
Python

import os
import random
import re
import string
from accounts.models import UserInstance, UserAttributes
from appsettings.settings import app_settings
from django.conf import settings
from django.db import transaction
from django.utils.translation import gettext_lazy as _
from libvirt import libvirtError
from logs.audit import reason, write
from vrtManager.instance import wvmInstance, wvmInstances
from .models import Instance
def can_open_console(user, instance):
"""
The single rule for console access (noVNC page, novncd, the virt-viewer
.vv file and the VDI URL): an active superuser or an active owner of the
VM. The global view_instances permission is read-only and does not grant
an interactive console.
"""
if not user.is_active:
return False
if user.is_superuser:
return True
return UserInstance.objects.filter(instance=instance, user=user).exists()
def get_clone_free_names(size=10):
prefix = app_settings.CLONE_INSTANCE_DEFAULT_PREFIX
free_names = []
existing_names = [i.name for i in Instance.objects.filter(name__startswith=prefix)]
index = 1
while len(free_names) < size:
new_name = prefix + str(index)
if new_name not in existing_names:
free_names.append(new_name)
index += 1
return free_names
# check_user_quota could not read every VM of the user: an increase is refused
QUOTA_UNVERIFIED = "unverified"
def check_user_quota(user, instance, cpu, memory, disk_size):
"""
Which quota the user would exceed by adding these amounts (instances,
vCPUs, memory MiB, disk GiB) to their VMs, or "". A quota of -1 has no
limit; 0 allows none. QUOTA_UNVERIFIED if a
VM that counts cannot be read (its host is down, the VM is gone): the
usage is unknown, so an increase is refused.
"""
ua, attributes_created = UserAttributes.objects.get_or_create(user=user)
msg = ""
if user.is_superuser:
return msg
# adding nothing (a shrink) cannot exceed a quota
if instance <= 0 and cpu <= 0 and memory <= 0 and disk_size <= 0:
return msg
quota_debug = app_settings.QUOTA_DEBUG == "True"
user_instances = UserInstance.objects.filter(user=user, instance__is_template=False).select_related(
"instance__compute"
)
instance += user_instances.count()
if ua.max_instances >= 0 and instance > ua.max_instances:
msg = "instance"
if quota_debug:
msg += f" ({instance} > {ua.max_instances})"
return msg
if ua.max_cpus < 0 and ua.max_memory < 0 and ua.max_disk_size < 0:
return msg
computes = {} # status is cached per object: check each host once
for usr_inst in user_instances:
vm = usr_inst.instance
compute = computes.setdefault(vm.compute_id, vm.compute)
if compute.status is not True:
return QUOTA_UNVERIFIED
try:
conn = wvmInstance(
compute.hostname,
compute.login,
compute.password,
compute.type,
vm.name,
uuid=vm.uuid,
)
cpu += int(conn.get_vcpu())
memory += int(conn.get_memory())
for disk in conn.get_disk_devices():
if disk["size"]:
disk_size += int(disk["size"]) >> 30
except libvirtError:
return QUOTA_UNVERIFIED
if ua.max_cpus >= 0 and cpu > ua.max_cpus:
msg = "cpu"
if quota_debug:
msg += f" ({cpu} > {ua.max_cpus})"
if ua.max_memory >= 0 and memory > ua.max_memory:
msg = "memory"
if quota_debug:
msg += f" ({memory} > {ua.max_memory})"
if ua.max_disk_size >= 0 and disk_size > ua.max_disk_size:
msg = "disk"
if quota_debug:
msg += f" ({disk_size} > {ua.max_disk_size})"
return msg
def get_new_disk_dev(media, disks, bus):
existing_disk_devs = []
existing_media_devs = []
if bus == "virtio":
dev_base = "vd"
elif bus == "ide":
dev_base = "hd"
elif bus == "fdc":
dev_base = "fd"
else:
dev_base = "sd"
if disks:
existing_disk_devs = [disk["dev"] for disk in disks]
# cd-rom bus could be virtio/sata, because of that we should check it also
if media:
existing_media_devs = [m["dev"] for m in media]
for al in string.ascii_lowercase:
dev = dev_base + al
if dev not in existing_disk_devs and dev not in existing_media_devs:
return dev
raise Exception(_("None available device name"))
def get_network_tuple(network_source_str):
network_source_pack = network_source_str.split(":", 1)
if len(network_source_pack) > 1:
return network_source_pack[1], network_source_pack[0]
else:
return network_source_pack[0], "net"
def migrate_instance(
new_compute,
instance,
user,
live=False,
unsafe=False,
offline=False,
autoconverge=False,
compress=False,
delete_source=False,
disk_pools=None,
):
"""Migrates instance to new_compute and logs the outcome (the mode
used, or the error), then each later step that failed in a row of its
own. disk_pools: {target: pool} of the disks copied into pools of
new_compute (moveto's pools); their source files go with delete_source
unless another VM or volume uses them, and are named in the log
otherwise. Returns the mode."""
source, target = instance.compute, migration_target(new_compute)
def log(action, error=None):
message = f"VM {instance.name}: {action}" + (f": {reason(error, user)}" if error is not None else "")
write(user.username, source.name, instance.name, message, error is None, uuid=instance.uuid)
conn_migrate = None
try:
conn_migrate = wvmInstances(
new_compute.hostname,
new_compute.login,
new_compute.password,
new_compute.type,
)
autostart = instance.proxy.get_autostart()
nvram = instance.proxy.get_nvram()
mode, copied = conn_migrate.moveto(
instance.proxy,
instance.name,
live,
unsafe,
offline,
autoconverge,
compress,
uri=new_compute.migration_uri,
pools=disk_pools,
)
except Exception as error:
log(f"migrate to {target}", error)
raise
finally:
if conn_migrate is not None:
conn_migrate.close()
# The VM runs on new_compute now: what follows must not stop it
# from being recorded there.
log(f"migrate ({mode}) to {target}")
if autostart:
conn_new = None
try:
conn_new = wvmInstance(
new_compute.hostname,
new_compute.login,
new_compute.password,
new_compute.type,
instance.name,
uuid=instance.uuid,
)
conn_new.set_autostart(1)
except (libvirtError, OSError) as error:
log(f"restore autostart on {target}", error)
finally:
if conn_new is not None:
conn_new.close()
in_use = set()
if copied and delete_source:
try:
in_use = instance.proxy.paths_in_use()
except libvirtError as error:
log("check the source copies before deleting them", error)
delete_source = False
for path in copied:
if not delete_source or path in in_use:
log(f"keep the source copy {path}" + (": another VM or volume uses it" if path in in_use else ""))
continue
try:
instance.proxy.get_volume_by_path(path).delete(0)
except libvirtError as error:
log(f"delete the source copy {path}", error)
else:
log(f"delete the source copy {path}")
# libvirt keeps the NVRAM file on the source; a VM created there
# later with the same name would start with these variables.
if nvram:
conn_new = None
try:
conn_new = wvmInstances(
new_compute.hostname, new_compute.login, new_compute.password, new_compute.type
)
instance.proxy.remove_nvram(nvram, conn_new)
except Exception as error: # the migration stands and is recorded
log(f"remove NVRAM file {nvram} on the source", error)
finally:
if conn_new is not None:
conn_new.close()
try:
record_migration(instance, new_compute)
except Exception as error:
log(f"record the move to {target}", error)
raise
return mode
def record_migration(instance, new_compute):
"""Moves instance to new_compute in the database. A record the list of
new_compute made for it meanwhile takes its owners and template mark."""
with transaction.atomic():
target_inst = Instance.objects.filter(compute=new_compute, uuid=instance.uuid).first()
if target_inst and target_inst.id != instance.id:
for ui in UserInstance.objects.filter(instance=instance):
existing_ui = UserInstance.objects.filter(instance=target_inst, user=ui.user).first()
if not existing_ui:
ui.instance = target_inst
ui.save()
else:
updated = False
if ui.is_change and not existing_ui.is_change:
existing_ui.is_change = True
updated = True
if ui.is_delete and not existing_ui.is_delete:
existing_ui.is_delete = True
updated = True
if ui.is_vnc and not existing_ui.is_vnc:
existing_ui.is_vnc = True
updated = True
if updated:
existing_ui.save()
ui.delete()
if instance.is_template and not target_inst.is_template:
target_inst.is_template = True
target_inst.save(update_fields=["is_template"])
instance.delete()
instance.id = target_inst.id
instance.compute = new_compute
else:
instance.compute = new_compute
instance.save()
def migration_target(compute):
"""The destination for the log: its host name, and the migration address
when one is set and differs."""
if compute.migration_address not in ("", compute.hostname):
return _("%(hostname)s via %(address)s") % {"hostname": compute.hostname, "address": compute.migration_address}
return compute.hostname
def refr(compute):
from computes.utils import refresh_instance_database
refresh_instance_database(compute)
def dhcpd_conf():
"""Optional dhcpd.conf in the application directory; clone names and MAC
addresses are taken from its host entries when it exists."""
return os.path.join(str(settings.BASE_DIR), "dhcpd.conf")
def get_dhcp_mac_address(vname):
dhcp_file = dhcpd_conf()
mac = ""
if os.path.isfile(dhcp_file):
with open(dhcp_file, "r") as f:
name_found = False
for line in f:
if "host %s." % vname in line:
name_found = True
if name_found and "hardware ethernet" in line:
mac = line.split(" ")[-1].strip().strip(";")
break
return mac
MAC_ADDRESS_RE = re.compile(r"^([0-9A-F]{2})(:?[0-9A-F]{2}){5}$", re.IGNORECASE)
def nic_macs(mac, networks):
"""The MAC addresses given for a new VM's NICs, in network order. NICs
without one get theirs from libvirt."""
macs = [m.strip() for m in mac.split(",")] if mac else []
if not all(MAC_ADDRESS_RE.fullmatch(m) for m in macs):
raise ValueError(_("Invalid MAC address"))
if len(macs) > len(networks.split(",")):
raise ValueError(_("More MAC addresses than networks"))
return macs
def get_random_mac_address():
mac = settings.MAC_OUI + ":%02x:%02x:%02x" % (
random.randint(0x00, 0xFF),
random.randint(0x00, 0xFF),
random.randint(0x00, 0xFF),
)
return mac
def get_clone_disk_name(disk, prefix, clone_name):
"""A volume name for the clone's copy of disk: the clone's name in place of
the source's (prefix), else before the disk's device and name, so two disks
of one clone do not get the same name."""
if not disk["image"]:
return None
if disk["image"].startswith(prefix):
suffix = disk["image"][len(prefix) :]
image = f"{clone_name}{suffix}"
elif "." in disk["image"] and len(disk["image"].rsplit(".", 1)[1]) <= 7:
name, suffix = disk["image"].rsplit(".", 1)
image = f"{clone_name}-{disk['dev']}-{name}.{suffix}"
else:
image = f"{clone_name}-{disk['dev']}-{disk['image']}"
# Derived names go into volume XML and paths: keep them to a safe charset.
image = re.sub(r"[^A-Za-z0-9_.+-]+", "-", image).lstrip("_.+-")
return image or None
def can_manage_console(user, instance):
"""
Who may see and change a VM's console settings, including its VNC
password: an active superuser, or an active owner with both is_change and
is_vnc; on a template only a staff owner (as get_instance(perm_type="change")).
is_staff and the global view_instances permission alone do not count.
"""
if not user.is_active:
return False
if user.is_superuser:
return True
if instance.is_template and not user.is_staff:
return False
return UserInstance.objects.filter(
instance=instance, user=user, is_change=True, is_vnc=True
).exists()