servers.py

import logging

from socket import getfqdn
from functools import wraps
from django import dispatch
from django.db import transaction
from django.utils import simplejson as json

from snf_django.lib.api import faults
from django.conf import settings
from synnefo import quotas
from synnefo.api import util
from synnefo.logic import backend, ips
from synnefo.logic.backend_allocator import BackendAllocator
from synnefo.db.models import (NetworkInterface, VirtualMachine,
                               VirtualMachineMetadata, IPAddressLog)
from vncauthproxy.client import request_forwarding as request_vnc_forwarding

log = logging.getLogger(__name__)

# server creation signal
server_created = dispatch.Signal(providing_args=["created_vm_params"])


def validate_server_action(vm, action):
    if vm.deleted:
        raise faults.BadRequest("Server '%s' has been deleted." % vm.id)

    # Destroyin a server should always be permitted
    if action == "DESTROY":
        return

    # Check that there is no pending action
    pending_action = vm.task
    if pending_action:
        if pending_action == "BUILD":
            raise faults.BuildInProgress("Server '%s' is being build." % vm.id)
        raise faults.BadRequest("Can not perform '%s' action while there is a"
                                " pending '%s'." % (action, pending_action))

    # Check if action can be performed to VM's operstate
    operstate = vm.operstate
    if operstate == "BUILD" and action != "BUILD":
        raise faults.BuildInProgress("Server '%s' is being build." % vm.id)
    elif (action == "START" and operstate != "STOPPED") or\
         (action == "STOP" and operstate != "STARTED") or\
         (action == "RESIZE" and operstate != "STOPPED") or\
         (action in ["CONNECT", "DISCONNECT"] and operstate != "STOPPED"
          and not settings.GANETI_USE_HOTPLUG):
        raise faults.BadRequest("Can not perform '%s' action while server is"
                                " in '%s' state." % (action, operstate))
    return


def server_command(action):
    """Handle execution of a server action.

    Helper function to validate and execute a server action, handle quota
    commission and update the 'task' of the VM in the DB.

    1) Check if action can be performed. If it can, then there must be no
       pending task (with the exception of DESTROY).
    2) Handle previous commission if unresolved:
       * If it is not pending and it to accept, then accept
       * If it is not pending and to reject or is pending then reject it. Since
       the action can be performed only if there is no pending task, then there
       can be no pending commission. The exception is DESTROY, but in this case
       the commission can safely be rejected, and the dispatcher will generate
       the correct ones!
    3) Issue new commission and associate it with the VM. Also clear the task.
    4) Send job to ganeti
    5) Update task and commit
    """
    def decorator(func):
        @wraps(func)
        @transaction.commit_on_success
        def wrapper(vm, *args, **kwargs):
            user_id = vm.userid
            validate_server_action(vm, action)
            vm.action = action

            commission_name = "client: api, resource: %s" % vm
            quotas.handle_resource_commission(vm, action=action,
                                              commission_name=commission_name)
            vm.save()

            # XXX: Special case for server creation!
            if action == "BUILD":
                # Perform a commit, because the VirtualMachine must be saved to
                # DB before the OP_INSTANCE_CREATE job in enqueued in Ganeti.
                # Otherwise, messages will arrive from snf-dispatcher about
                # this instance, before the VM is stored in DB.
                transaction.commit()
                # After committing the locks are released. Refetch the instance
                # to guarantee x-lock.
                vm = VirtualMachine.objects.select_for_update().get(id=vm.id)

            # Send the job to Ganeti and get the associated jobID
            try:
                job_id = func(vm, *args, **kwargs)
            except Exception as e:
                if vm.serial is not None:
                    # Since the job never reached Ganeti, reject the commission
                    log.debug("Rejecting commission: '%s', could not perform"
                              " action '%s': %s" % (vm.serial,  action, e))
                    transaction.rollback()
                    quotas.reject_serial(vm.serial)
                    transaction.commit()
                raise

            if action == "BUILD" and vm.serial is not None:
                # XXX: Special case for server creation: we must accept the
                # commission because the VM has been stored in DB. Also, if
                # communication with Ganeti fails, the job will never reach
                # Ganeti, and the commission will never be resolved.
                quotas.accept_serial(vm.serial)

            log.info("user: %s, vm: %s, action: %s, job_id: %s, serial: %s",
                     user_id, vm.id, action, job_id, vm.serial)

            # store the new task in the VM
            if job_id is not None:
                vm.task = action
                vm.task_job_id = job_id
            vm.save()

            return vm
        return wrapper
    return decorator


@transaction.commit_on_success
def create(userid, name, password, flavor, image, metadata={},
           personality=[], networks=None, floating_ips=None,
           use_backend=None):
    if use_backend is None:
        # Allocate server to a Ganeti backend
        use_backend = allocate_new_server(userid, flavor)

    if networks is None:
        networks = []
    if floating_ips is None:
        floating_ips = []

    # Fix flavor for archipelago
    disk_template, provider = util.get_flavor_provider(flavor)
    if provider:
        flavor.disk_template = disk_template
        flavor.disk_provider = provider
        flavor.disk_origin = None
        if provider == 'vlmc':
            flavor.disk_origin = image['checksum']
            image['backend_id'] = 'null'
    else:
        flavor.disk_provider = None

    # We must save the VM instance now, so that it gets a valid
    # vm.backend_vm_id.
    vm = VirtualMachine.objects.create(name=name,
                                       backend=use_backend,
                                       userid=userid,
                                       imageid=image["id"],
                                       flavor=flavor,
                                       operstate="BUILD")
    log.info("Created entry in DB for VM '%s'", vm)

    nics = create_instance_nics(vm, userid, networks, floating_ips)

    for key, val in metadata.items():
        VirtualMachineMetadata.objects.create(
            meta_key=key,
            meta_value=val,
            vm=vm)

    # Create the server in Ganeti.
    vm = create_server(vm, nics, flavor, image, personality, password)

    return vm


@transaction.commit_on_success
def allocate_new_server(userid, flavor):
    """Allocate a new server to a Ganeti backend.

    Allocation is performed based on the owner of the server and the specified
    flavor. Also, backends that do not have a public IPv4 address are excluded
    from server allocation.

    This function runs inside a transaction, because after allocating the
    instance a commit must be performed in order to release all locks.

    """
    backend_allocator = BackendAllocator()
    use_backend = backend_allocator.allocate(userid, flavor)
    if use_backend is None:
        log.error("No available backend for VM with flavor %s", flavor)
        raise faults.ServiceUnavailable("No available backends")
    return use_backend


@server_command("BUILD")
def create_server(vm, nics, flavor, image, personality, password):
    # dispatch server created signal needed to trigger the 'vmapi', which
    # enriches the vm object with the 'config_url' attribute which must be
    # passed to the Ganeti job.
    server_created.send(sender=vm, created_vm_params={
        'img_id': image['backend_id'],
        'img_passwd': password,
        'img_format': str(image['format']),
        'img_personality': json.dumps(personality),
        'img_properties': json.dumps(image['metadata']),
    })
    # send job to Ganeti
    try:
        jobID = backend.create_instance(vm, nics, flavor, image)
    except:
        log.exception("Failed create instance '%s'", vm)
        jobID = None
        vm.operstate = "ERROR"
        vm.backendlogmsg = "Failed to send job to Ganeti."
        vm.save()
        vm.nics.all().update(state="ERROR")

    # At this point the job is enqueued in the Ganeti backend
    vm.backendjobid = jobID
    vm.save()
    log.info("User %s created VM %s, NICs %s, Backend %s, JobID %s",
             vm.userid, vm, nics, backend, str(jobID))

    return jobID


def create_instance_nics(vm, userid, networks=[], floating_ips=[]):
    """Create NICs for VirtualMachine.

    Helper function for allocating IP addresses and creating NICs in the DB
    for a VirtualMachine. Created NICs are the combination of the default
    network policy (defined by administration settings) and the networks
    defined by the user.

    """
    ports = []
    for network_id in settings.DEFAULT_INSTANCE_NETWORKS:
        if network_id == "SNF:ANY_PUBLIC":
            ipaddress = ips.allocate_public_ip(userid=userid,
                                               backend=vm.backend)
            port = _create_port(userid, network=ipaddress.network,
                                use_ipaddress=ipaddress)
        else:
            try:
                network = util.get_network(network_id, userid,
                                           non_deleted=True)
            except faults.ItemNotFound:
                msg = "Invalid configuration. Setting"\
                      " 'DEFAULT_INSTANCE_NETWORKS' contains invalid"\
                      " network '%s'" % network_id
                log.error(msg)
                raise faults.InternalServerError(msg)
            port = _create_port(userid, network)
        ports.append(port)

    for floating_ip_id in floating_ips:
        floating_ip = util.get_floating_ip_by_id(userid, floating_ip_id,
                                                 for_update=True)
        port = _create_port(userid, network=floating_ip.network,
                            use_ipaddress=floating_ip)
        ports.append(port)

    for net in networks:
        port_id = net.get("port")
        net_id = net.get("uuid")
        if port_id is not None:
            port = util.get_port(port_id, userid, for_update=True)
            ports.append(port)
        elif net_id is not None:
            address = net.get("fixed_ip")
            network = util.get_network(net_id, userid, non_deleted=True)
            if network.public:
                if address is None:
                    msg = ("Can not connect to public network %s. Specify"
                           " 'fixed_ip'" " attribute to connect to a public"
                           " network")
                    raise faults.BadRequest(msg % network.id)
                floating_ip = util.get_floating_ip_by_address(userid,
                                                              address,
                                                              for_update=True)
                port = _create_port(userid, network, use_ipaddress=floating_ip)
            else:
                port = _create_port(userid, network, address=address)
            ports.append(port)
        else:
            raise faults.BadRequest("Network 'uuid' or 'port' attribute"
                                    " is required.")

    for index, port in enumerate(ports):
        associate_port_with_machine(port, vm)
        port.index = index
        port.save()
    return ports


@server_command("DESTROY")
def destroy(vm):
    log.info("Deleting VM %s", vm)
    return backend.delete_instance(vm)


@server_command("START")
def start(vm):
    log.info("Starting VM %s", vm)
    return backend.startup_instance(vm)


@server_command("STOP")
def stop(vm):
    log.info("Stopping VM %s", vm)
    return backend.shutdown_instance(vm)


@server_command("REBOOT")
def reboot(vm, reboot_type):
    if reboot_type not in ("SOFT", "HARD"):
        raise faults.BadRequest("Malformed request. Invalid reboot"
                                " type %s" % reboot_type)
    log.info("Rebooting VM %s. Type %s", vm, reboot_type)

    return backend.reboot_instance(vm, reboot_type.lower())


@server_command("RESIZE")
def resize(vm, flavor):
    old_flavor = vm.flavor
    # User requested the same flavor
    if old_flavor.id == flavor.id:
        raise faults.BadRequest("Server '%s' flavor is already '%s'."
                                % (vm, flavor))
        return None
    # Check that resize can be performed
    if old_flavor.disk != flavor.disk:
        raise faults.BadRequest("Can not resize instance disk.")
    if old_flavor.disk_template != flavor.disk_template:
        raise faults.BadRequest("Can not change instance disk template.")

    log.info("Resizing VM from flavor '%s' to '%s", old_flavor, flavor)
    commission_info = {"cyclades.cpu": flavor.cpu - old_flavor.cpu,
                       "cyclades.ram": 1048576 * (flavor.ram - old_flavor.ram)}
    # Save serial to VM, since it is needed by server_command decorator
    vm.serial = quotas.issue_commission(user=vm.userid,
                                        source=quotas.DEFAULT_SOURCE,
                                        provisions=commission_info,
                                        name="resource: %s. resize" % vm)
    return backend.resize_instance(vm, vcpus=flavor.cpu, memory=flavor.ram)


@server_command("SET_FIREWALL_PROFILE")
def set_firewall_profile(vm, profile, nic):
    log.info("Setting VM %s, NIC %s, firewall %s", vm, nic, profile)

    if profile not in [x[0] for x in NetworkInterface.FIREWALL_PROFILES]:
        raise faults.BadRequest("Unsupported firewall profile")
    backend.set_firewall_profile(vm, profile=profile, nic=nic)
    return None


@server_command("CONNECT")
def connect(vm, network, port=None):
    if port is None:
        port = _create_port(vm.userid, network)
    associate_port_with_machine(port, vm)

    log.info("Creating NIC %s with IPv4 Address %s", port, port.ipv4_address)

    return backend.connect_to_network(vm, port)


@server_command("DISCONNECT")
def disconnect(vm, nic):
    log.info("Removing NIC %s from VM %s", nic, vm)
    return backend.disconnect_from_network(vm, nic)


def console(vm, console_type):
    """Arrange for an OOB console of the specified type

    This method arranges for an OOB console of the specified type.
    Only consoles of type "vnc" are supported for now.

    It uses a running instance of vncauthproxy to setup proper
    VNC forwarding with a random password, then returns the necessary
    VNC connection info to the caller.

    """
    log.info("Get console  VM %s, type %s", vm, console_type)

    # Use RAPI to get VNC console information for this instance
    if vm.operstate != "STARTED":
        raise faults.BadRequest('Server not in ACTIVE state.')

    if settings.TEST:
        console_data = {'kind': 'vnc', 'host': 'ganeti_node', 'port': 1000}
    else:
        console_data = backend.get_instance_console(vm)

    if console_data['kind'] != 'vnc':
        message = 'got console of kind %s, not "vnc"' % console_data['kind']
        raise faults.ServiceUnavailable(message)

    # Let vncauthproxy decide on the source port.
    # The alternative: static allocation, e.g.
    # sport = console_data['port'] - 1000
    sport = 0
    daddr = console_data['host']
    dport = console_data['port']
    password = util.random_password()

    if settings.TEST:
        fwd = {'source_port': 1234, 'status': 'OK'}
    else:
        fwd = request_vnc_forwarding(sport, daddr, dport, password)

    if fwd['status'] != "OK":
        raise faults.ServiceUnavailable('vncauthproxy returned error status')

    # Verify that the VNC server settings haven't changed
    if not settings.TEST:
        if console_data != backend.get_instance_console(vm):
            raise faults.ServiceUnavailable('VNC Server settings changed.')

    console = {
        'type': 'vnc',
        'host': getfqdn(),
        'port': fwd['source_port'],
        'password': password}

    return console


def rename(server, new_name):
    """Rename a VirtualMachine."""
    old_name = server.name
    server.name = new_name
    server.save()
    log.info("Renamed server '%s' from '%s' to '%s'", server, old_name,
             new_name)
    return server


@transaction.commit_on_success
def create_port(*args, **kwargs):
    return _create_port(*args, **kwargs)


def _create_port(userid, network, machine=None, use_ipaddress=None,
                 address=None, name="", security_groups=None,
                 device_owner=None):
    """Create a new port on the specified network.

    Create a new Port(NetworkInterface model) on the specified Network. If
    'machine' is specified, the machine will be connected to the network using
    this port. If 'use_ipaddress' argument is specified, the port will be
    assigned this IPAddress. Otherwise, an IPv4 address from the IPv4 subnet
    will be allocated.

    """
    if network.state != "ACTIVE":
        raise faults.BuildInProgress("Can not create port while network is in"
                                     " state %s" % network.state)
    if network.action == "DESTROY":
        msg = "Can not create port. Network %s is being deleted."
        raise faults.Conflict(msg % network.id)
    ipaddress = None
    if use_ipaddress is not None:
        # Use an existing IPAddress object.
        ipaddress = use_ipaddress
        if ipaddress and (ipaddress.network_id != network.id):
            msg = "IP Address %s does not belong to network %s"
            raise faults.Conflict(msg % (ipaddress.address, network.id))
    else:
        # If network has IPv4 subnets, try to allocate the address that the
        # the user specified or a random one.
        if network.subnets.filter(ipversion=4).exists():
            ipaddress = ips.allocate_ip(network, userid=userid,
                                        address=address)
        elif address is not None:
            raise faults.BadRequest("Address %s is not a valid IP for the"
                                    " defined network subnets" % address)

    if ipaddress is not None and ipaddress.nic is not None:
        raise faults.Conflict("IP address '%s' is already in use" %
                              ipaddress.address)

    port = NetworkInterface.objects.create(network=network,
                                           state="DOWN",
                                           userid=userid,
                                           device_owner=None,
                                           name=name)

    # add the security groups if any
    if security_groups:
        port.security_groups.add(*security_groups)

    if ipaddress is not None:
        # Associate IPAddress with the Port
        ipaddress.nic = port
        ipaddress.save()

    if machine is not None:
        # Connect port to the instance.
        machine = connect(machine, network, port)
        jobID = machine.task_job_id
        log.info("Created Port %s with IP %s. Ganeti Job: %s",
                 port, ipaddress, jobID)
    else:
        log.info("Created Port %s with IP %s not attached to any instance",
                 port, ipaddress)

    return port


def associate_port_with_machine(port, machine):
    """Associate a Port with a VirtualMachine.

    Associate the port with the VirtualMachine and add an entry to the
    IPAddressLog if the port has a public IPv4 address from a public network.

    """
    if port.machine is not None:
        raise faults.Conflict("Port %s is already in use." % port.id)
    if port.network.public:
        ipv4_address = port.ipv4_address
        if ipv4_address is not None:
            ip_log = IPAddressLog.objects.create(server_id=machine.id,
                                                 network_id=port.network_id,
                                                 address=ipv4_address,
                                                 active=True)
            log.debug("Created IP log entry %s", ip_log)
    port.machine = machine
    port.state = "BUILD"
    port.device_owner = "vm"
    port.save()
    return port


@transaction.commit_on_success
def delete_port(port):
    """Delete a port by removing the NIC card from the instance.

    Send a Job to remove the NIC card from the instance. The port
    will be deleted and the associated IPv4 addressess will be released
    when the job completes successfully.

    """

    if port.machine is not None:
        vm = disconnect(port.machine, port)
        log.info("Removing port %s, Job: %s", port, vm.task_job_id)
    else:
        backend.remove_nic_ips(port)
        port.delete()
        log.info("Removed port %s", port)

    return port