uncloud-mravi/host/virtualmachine.py

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# QEMU Manual
# https://qemu.weilnetz.de/doc/qemu-doc.html
# For QEMU Monitor Protocol Commands Information, See
# https://qemu.weilnetz.de/doc/qemu-doc.html#pcsys_005fmonitor
import os
import random
import subprocess as sp
import tempfile
import time
from functools import wraps
from os.path import join as join_path
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from string import Template
from typing import Union
import bitmath
import sshtunnel
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from common.helpers import get_ipv6_address
from common.request import RequestEntry, RequestType
from common.vm import VMEntry, VMStatus
from config import etcd_client, request_pool, running_vms, vm_pool, env_vars, image_storage_handler
from . import qmp
from host import logger
class VM:
def __init__(self, key, handle, vnc_socket_file):
self.key = key # type: str
self.handle = handle # type: qmp.QEMUMachine
self.vnc_socket_file = vnc_socket_file # type: tempfile.NamedTemporaryFile
def __repr__(self):
return "VM({})".format(self.key)
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def create_dev(script, _id, dev, ip=None):
command = [script, _id, dev]
if ip:
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command.append(ip)
try:
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output = sp.check_output(command, stderr=sp.PIPE)
except Exception as e:
print(e.stderr)
return None
else:
return output.decode("utf-8").strip()
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def create_vxlan_br_tap(_id, _dev, ip=None):
network_script_base = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'network')
vxlan = create_dev(script=os.path.join(network_script_base, 'create-vxlan.sh'),
_id=_id, dev=_dev)
if vxlan:
bridge = create_dev(script=os.path.join(network_script_base, 'create-bridge.sh'),
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_id=_id, dev=vxlan, ip=ip)
if bridge:
tap = create_dev(script=os.path.join(network_script_base, 'create-tap.sh'),
_id=str(random.randint(1, 100000)), dev=bridge)
if tap:
return tap
def random_bytes(num=6):
return [random.randrange(256) for _ in range(num)]
def generate_mac(uaa=False, multicast=False, oui=None, separator=':', byte_fmt='%02x'):
mac = random_bytes()
if oui:
if type(oui) == str:
oui = [int(chunk) for chunk in oui.split(separator)]
mac = oui + random_bytes(num=6 - len(oui))
else:
if multicast:
mac[0] |= 1 # set bit 0
else:
mac[0] &= ~1 # clear bit 0
if uaa:
mac[0] &= ~(1 << 1) # clear bit 1
else:
mac[0] |= 1 << 1 # set bit 1
return separator.join(byte_fmt % b for b in mac)
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def update_radvd_conf(etcd_client):
network_script_base = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'network')
networks = {
net.value['ipv6']: net.value['id']
for net in etcd_client.get_prefix('/v1/network/', value_in_json=True)
if net.value.get('ipv6')
}
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radvd_template = open(os.path.join(network_script_base,
'radvd-template.conf'), 'r').read()
radvd_template = Template(radvd_template)
content = [radvd_template.safe_substitute(bridge='br{}'.format(networks[net]),
prefix=net)
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for net in networks if networks.get(net)]
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with open('/etc/radvd.conf', 'w') as radvd_conf:
radvd_conf.writelines(content)
sp.check_output(['systemctl', 'restart', 'radvd'])
def get_start_command_args(vm_entry, vnc_sock_filename: str, migration=False, migration_port=None):
threads_per_core = 1
vm_memory = int(bitmath.parse_string_unsafe(vm_entry.specs["ram"]).to_MB())
vm_cpus = int(vm_entry.specs["cpu"])
vm_uuid = vm_entry.uuid
vm_networks = vm_entry.network
command = "-name {}_{}".format(vm_entry.owner, vm_entry.name)
command += " -drive file={},format=raw,if=virtio,cache=none".format(
image_storage_handler.qemu_path_string(vm_uuid)
)
command += " -device virtio-rng-pci -vnc unix:{}".format(vnc_sock_filename)
command += " -m {} -smp cores={},threads={}".format(
vm_memory, vm_cpus, threads_per_core
)
if migration:
command += " -incoming tcp:[::]:{}".format(migration_port)
tap = None
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for network_and_mac in vm_networks:
network_name, mac = network_and_mac
_key = os.path.join(env_vars.get('NETWORK_PREFIX'), vm_entry.owner, network_name)
network = etcd_client.get(_key, value_in_json=True)
network_type = network.value["type"]
network_id = str(network.value["id"])
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network_ipv6 = network.value["ipv6"]
if network_type == "vxlan":
tap = create_vxlan_br_tap(network_id, env_vars.get("VXLAN_PHY_DEV"), network_ipv6)
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update_radvd_conf(etcd_client)
command += " -netdev tap,id=vmnet{net_id},ifname={tap},script=no,downscript=no" \
" -device virtio-net-pci,netdev=vmnet{net_id},mac={mac}" \
.format(tap=tap, net_id=network_id, mac=mac)
return command.split(" ")
def create_vm_object(vm_entry, migration=False, migration_port=None):
# NOTE: If migration suddenly stop working, having different
# VNC unix filename on source and destination host can
# be a possible cause of it.
# REQUIREMENT: Use Unix Socket instead of TCP Port for VNC
vnc_sock_file = tempfile.NamedTemporaryFile()
qemu_args = get_start_command_args(
vm_entry=vm_entry,
vnc_sock_filename=vnc_sock_file.name,
migration=migration,
migration_port=migration_port,
)
qemu_machine = qmp.QEMUMachine("/usr/bin/qemu-system-x86_64", args=qemu_args)
return VM(vm_entry.key, qemu_machine, vnc_sock_file)
def get_vm(vm_list: list, vm_key) -> Union[VM, None]:
return next((vm for vm in vm_list if vm.key == vm_key), None)
def need_running_vm(func):
@wraps(func)
def wrapper(e):
vm = get_vm(running_vms, e.key)
if vm:
try:
status = vm.handle.command("query-status")
logger.debug("VM Status Check - %s", status)
except Exception as exception:
logger.info("%s failed - VM %s %s", func.__name__, e, exception)
else:
return func(e)
return None
else:
logger.info("%s failed because VM %s is not running", func.__name__, e.key)
return None
return wrapper
def create(vm_entry: VMEntry):
if image_storage_handler.is_vm_image_exists(vm_entry.uuid):
# File Already exists. No Problem Continue
logger.debug("Image for vm %s exists", vm_entry.uuid)
else:
vm_hdd = int(bitmath.parse_string_unsafe(vm_entry.specs["os-ssd"]).to_MB())
if image_storage_handler.make_vm_image(src=vm_entry.image_uuid, dest=vm_entry.uuid):
if not image_storage_handler.resize_vm_image(path=vm_entry.uuid, size=vm_hdd):
vm_entry.status = VMStatus.error
else:
logger.info("New VM Created")
def start(vm_entry: VMEntry, destination_host_key=None, migration_port=None):
_vm = get_vm(running_vms, vm_entry.key)
# VM already running. No need to proceed further.
if _vm:
logger.info("VM %s already running" % vm_entry.uuid)
return
else:
logger.info("Trying to start %s" % vm_entry.uuid)
if destination_host_key:
launch_vm(vm_entry, migration=True, migration_port=migration_port,
destination_host_key=destination_host_key)
else:
create(vm_entry)
launch_vm(vm_entry)
@need_running_vm
def stop(vm_entry):
vm = get_vm(running_vms, vm_entry.key)
vm.handle.shutdown()
if not vm.handle.is_running():
vm_entry.add_log("Shutdown successfully")
vm_entry.declare_stopped()
vm_pool.put(vm_entry)
running_vms.remove(vm)
def delete(vm_entry):
logger.info("Deleting VM | %s", vm_entry)
stop(vm_entry)
r_status = image_storage_handler.delete_vm_image(vm_entry.uuid)
if r_status:
etcd_client.client.delete(vm_entry.key)
def transfer(request_event):
# This function would run on source host i.e host on which the vm
# is running initially. This host would be responsible for transferring
# vm state to destination host.
_host, _port = request_event.parameters["host"], request_event.parameters["port"]
_uuid = request_event.uuid
_destination = request_event.destination_host_key
vm = get_vm(running_vms, join_path(env_vars.get('VM_PREFIX'), _uuid))
if vm:
tunnel = sshtunnel.SSHTunnelForwarder(
_host,
ssh_username=env_vars.get("ssh_username"),
ssh_pkey=env_vars.get("ssh_pkey"),
remote_bind_address=("127.0.0.1", _port),
ssh_proxy_enabled=True,
ssh_proxy=(_host, 22)
)
try:
tunnel.start()
except sshtunnel.BaseSSHTunnelForwarderError:
logger.exception("Couldn't establish connection to (%s, 22)", _host)
else:
vm.handle.command(
"migrate", uri="tcp:0.0.0.0:{}".format(tunnel.local_bind_port)
)
status = vm.handle.command("query-migrate")["status"]
while status not in ["failed", "completed"]:
time.sleep(2)
status = vm.handle.command("query-migrate")["status"]
with vm_pool.get_put(request_event.uuid) as source_vm:
if status == "failed":
source_vm.add_log("Migration Failed")
elif status == "completed":
# If VM is successfully migrated then shutdown the VM
# on this host and update hostname to destination host key
source_vm.add_log("Successfully migrated")
source_vm.hostname = _destination
running_vms.remove(vm)
vm.handle.shutdown()
source_vm.in_migration = False # VM transfer finished
finally:
tunnel.close()
def launch_vm(vm_entry, migration=False, migration_port=None, destination_host_key=None):
logger.info("Starting %s" % vm_entry.key)
vm = create_vm_object(vm_entry, migration=migration, migration_port=migration_port)
try:
vm.handle.launch()
except Exception:
logger.exception("Error Occured while starting VM")
vm.handle.shutdown()
if migration:
# We don't care whether MachineError or any other error occurred
pass
else:
# Error during typical launch of a vm
vm.handle.shutdown()
vm_entry.declare_killed()
vm_pool.put(vm_entry)
else:
vm_entry.vnc_socket = vm.vnc_socket_file.name
running_vms.append(vm)
if migration:
vm_entry.in_migration = True
r = RequestEntry.from_scratch(
type=RequestType.TransferVM,
hostname=vm_entry.hostname,
parameters={"host": get_ipv6_address(), "port": migration_port},
uuid=vm_entry.uuid,
destination_host_key=destination_host_key,
request_prefix=env_vars.get("REQUEST_PREFIX")
)
request_pool.put(r)
else:
# Typical launching of a vm
vm_entry.status = VMStatus.running
vm_entry.add_log("Started successfully")
vm_pool.put(vm_entry)