# 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 string import Template from typing import Union from os.path import join as join_path import bitmath import sshtunnel from ucloud.common.helpers import get_ipv6_address from ucloud.common.request import RequestEntry, RequestType from ucloud.common.vm import VMEntry, VMStatus from ucloud.config import (etcd_client, request_pool, running_vms, vm_pool, config, image_storage_handler) from . import qmp from ucloud.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) def delete_network_interface(iface): try: sp.check_output(['ip', 'link', 'del', iface]) except Exception: pass def resolve_network(network_name, network_owner): network = etcd_client.get(join_path(config['etcd']['network_prefix'], network_owner, network_name), value_in_json=True) return network def delete_vm_network(vm_entry): try: for network in vm_entry.network: network_name = network[0] tap_mac = network[1] tap_id = network[2] delete_network_interface('tap{}'.format(tap_id)) owners_vms = vm_pool.by_owner(vm_entry.owner) owners_running_vms = vm_pool.by_status(VMStatus.running, _vms=owners_vms) networks = map(lambda n: n[0], map(lambda vm: vm.network, owners_running_vms) ) networks_in_use_by_user_vms = [vm[0] for vm in networks] if network_name not in networks_in_use_by_user_vms: network_entry = resolve_network(network[0], vm_entry.owner) if network_entry: network_type = network_entry.value["type"] network_id = network_entry.value["id"] if network_type == "vxlan": delete_network_interface('br{}'.format(network_id)) delete_network_interface('vxlan{}'.format(network_id)) except Exception: logger.exception("Exception in network interface deletion") def create_dev(script, _id, dev, ip=None): command = [script, _id, dev] if ip: command.append(ip) try: output = sp.check_output(command, stderr=sp.PIPE) except Exception as e: print(e.stderr) return None else: return output.decode("utf-8").strip() def create_vxlan_br_tap(_id, _dev, tap_id, 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'), _id=_id, dev=vxlan, ip=ip) if bridge: tap = create_dev(script=os.path.join(network_script_base, 'create-tap.sh'), _id=str(tap_id), 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) 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') } 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) for net in networks if networks.get(net)] with open('/etc/radvd.conf', 'w') as radvd_conf: radvd_conf.writelines(content) try: sp.check_output(['systemctl', 'restart', 'radvd']) except Exception: sp.check_output(['service', 'radvd', 'restart']) 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 for network_mac_and_tap in vm_networks: network_name, mac, tap = network_mac_and_tap _key = os.path.join(config['etcd']['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"]) network_ipv6 = network.value["ipv6"] if network_type == "vxlan": tap = create_vxlan_br_tap(_id=network_id, _dev=config['network']['vxlan_phy_dev'], tap_id=tap, ip=network_ipv6) 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) delete_vm_network(vm_entry) def delete(vm_entry): logger.info("Deleting VM | %s", vm_entry) stop(vm_entry) if image_storage_handler.is_vm_image_exists(vm_entry.uuid): r_status = image_storage_handler.delete_vm_image(vm_entry.uuid) if r_status: etcd_client.client.delete(vm_entry.key) else: 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(config['etcd']['vm_prefix'], _uuid)) if vm: tunnel = sshtunnel.SSHTunnelForwarder( _host, ssh_username=config['ssh']['username'], ssh_pkey=config['ssh']['private_key_path'], 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=config['etcd']['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)