uncloud/ucloud/host/virtualmachine.py

# 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 subprocess as sp
import ipaddress

from string import Template
from os.path import join as join_path

from ucloud.common.request import RequestEntry, RequestType
from ucloud.common.vm import VMStatus, declare_stopped
from ucloud.common.network import create_dev, delete_network_interface
from ucloud.common.schemas import VMSchema, NetworkSchema
from ucloud.host import logger
from ucloud.shared import shared
from ucloud.settings import settings
from ucloud.vmm import VMM

from marshmallow import ValidationError


def maintenance():
    pass


class VM:
    def __init__(self, vm_entry):
        self.schema = VMSchema()
        self.vmm = VMM()
        self.key = vm_entry.key
        try:
            self.vm = self.schema.loads(vm_entry.value)
        except ValidationError:
            logger.exception('Couldn\'t validate VM Entry', vm_entry.value)
            self.vm = None
        else:
            self.uuid = vm_entry.key.split('/')[-1]
            self.host_key = self.vm['hostname']

    def get_qemu_args(self):
        command = (
            '-name {owner}_{name}'
            ' -drive file={file},format=raw,if=virtio,cache=none'
            ' -device virtio-rng-pci'
            ' -m {memory} -smp cores={cores},threads={threads}'
        ).format(owner=self.vm['owner'], name=self.vm['name'],
                 memory=int(self.vm['specs']['ram'].to_MB()), cores=self.vm['specs']['cpu'],
                 threads=1, file=shared.storage_handler.qemu_path_string(self.uuid))

        return command.split(' ')

    def start(self, destination_host_key=None):
        migration = False
        if destination_host_key:
            migration = True

        self.create()
        try:
            network_args = self.create_network_dev()
        except Exception as err:
            declare_stopped(self.vm)
            self.vm['log'].append('Cannot Setup Network Properly')
            logger.error('Cannot Setup Network Properly for vm %s', self.uuid, exc_info=err)
        else:
            self.vmm.start(uuid=self.uuid, migration=migration,
                           *self.get_qemu_args(), *network_args)

            status = self.vmm.get_status(self.uuid)
            if status == 'running':
                self.vm['status'] = VMStatus.running
                self.vm['vnc_socket'] = self.vmm.get_vnc(self.uuid)
            elif status == 'inmigrate':
                r = RequestEntry.from_scratch(
                    type=RequestType.TransferVM,  # Transfer VM
                    hostname=self.host_key,  # Which VM should get this request. It is source host
                    uuid=self.uuid,  # uuid of VM
                    destination_host_key=destination_host_key,  # Where source host transfer VM
                    request_prefix=settings['etcd']['request_prefix']
                )
                shared.request_pool.put(r)
            else:
                self.stop()
                declare_stopped(self.vm)

        self.sync()

    def stop(self):
        self.vmm.stop(self.uuid)
        self.delete_network_dev()
        declare_stopped(self.vm)
        self.sync()

    def migrate(self, destination):
        self.vmm.transfer(src_uuid=self.uuid, dest_uuid=self.uuid, host=destination)

    def create_network_dev(self):
        command = ''
        for network_mac_and_tap in self.vm['network']:
            network_name, mac, tap = network_mac_and_tap

            _key = os.path.join(settings['etcd']['network_prefix'], self.vm['owner'], network_name)
            network = shared.etcd_client.get(_key, value_in_json=True)
            network_schema = NetworkSchema()
            try:
                network = network_schema.load(network.value)
            except ValidationError:
                continue

            if network['type'] == "vxlan":
                tap = create_vxlan_br_tap(_id=network['id'],
                                          _dev=settings['network']['vxlan_phy_dev'],
                                          tap_id=tap,
                                          ip=network['ipv6'])

                all_networks = shared.etcd_client.get_prefix(settings['etcd']['network_prefix'],
                                                             value_in_json=True)

                if ipaddress.ip_network(network['ipv6']).is_global:
                    update_radvd_conf(all_networks)

            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 delete_network_dev(self):
        try:
            for network in self.vm['network']:
                network_name = network[0]
                _ = network[1]  # tap_mac
                tap_id = network[2]

                delete_network_interface('tap{}'.format(tap_id))

                owners_vms = shared.vm_pool.by_owner(self.vm['owner'])
                owners_running_vms = shared.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], self.vm['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(self):
        if shared.storage_handler.is_vm_image_exists(self.uuid):
            # File Already exists. No Problem Continue
            logger.debug("Image for vm %s exists", self.uuid)
        else:
            if shared.storage_handler.make_vm_image(src=self.vm['image_uuid'], dest=self.uuid):
                if not shared.storage_handler.resize_vm_image(path=self.uuid,
                                                              size=int(self.vm['specs']['os-ssd'].to_MB())):
                    self.vm['status'] = VMStatus.error
                else:
                    logger.info("New VM Created")

    def sync(self):
        shared.etcd_client.put(self.key, self.schema.dump(self.vm), value_in_json=True)

    def delete(self):
        self.stop()

        if shared.storage_handler.is_vm_image_exists(self.uuid):
            r_status = shared.storage_handler.delete_vm_image(self.uuid)
            if r_status:
                shared.etcd_client.client.delete(self.key)
        else:
            shared.etcd_client.client.delete(self.key)


def resolve_network(network_name, network_owner):
    network = shared.etcd_client.get(
        join_path(settings['etcd']['network_prefix'], network_owner, network_name), value_in_json=True
    )
    return network


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 update_radvd_conf(all_networks):
    network_script_base = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'network')

    networks = {
        net.value['ipv6']: net.value['id']
        for net in all_networks
        if net.value.get('ipv6') and ipaddress.ip_network(net.value.get('ipv6')).is_global
    }
    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 sp.CalledProcessError:
        try:
            sp.check_output(['service', 'radvd', 'restart'])
        except sp.CalledProcessError as err:
            raise err.__class__('Cannot start/restart radvd service', err.cmd) from err