Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

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from base64 import b64encode, b64decode

from hashlib import sha256

from logging import getLogger

from random import choice

from string import digits, lowercase, uppercase

from Crypto.Cipher import AES

from django.conf import settings

from django.http import HttpResponse

from django.template.loader import render_to_string

from django.utils import simplejson as json

from django.db.models import Q

from snf_django.lib.api import faults

from synnefo.db.models import (Flavor, VirtualMachine, VirtualMachineMetadata,

                               Network, NetworkInterface, SecurityGroup,

                               BridgePoolTable, MacPrefixPoolTable, IPAddress,

                               IPPoolTable)

from synnefo.db import pools

from synnefo.plankton.utils import image_backend

from synnefo.cyclades_settings import cyclades_services, BASE_HOST

from synnefo.lib.services import get_service_path

from synnefo.lib import join_urls

COMPUTE_URL = \

    join_urls(BASE_HOST,

              get_service_path(cyclades_services, "compute", version="v2.0"))

SERVERS_URL = join_urls(COMPUTE_URL, "servers/")

NETWORKS_URL = join_urls(COMPUTE_URL, "networks/")

FLAVORS_URL = join_urls(COMPUTE_URL, "flavors/")

IMAGES_URL = join_urls(COMPUTE_URL, "images/")

PLANKTON_URL = \

    join_urls(BASE_HOST,

              get_service_path(cyclades_services, "image", version="v1.0"))

IMAGES_PLANKTON_URL = join_urls(PLANKTON_URL, "images/")

PITHOSMAP_PREFIX = "pithosmap://"

log = getLogger('synnefo.api')

def random_password():

    """Generates a random password

    We generate a windows compliant password: it must contain at least

    one charachter from each of the groups: upper case, lower case, digits.

    """

    pool = lowercase + uppercase + digits

    lowerset = set(lowercase)

    upperset = set(uppercase)

    digitset = set(digits)

    length = 10

    password = ''.join(choice(pool) for i in range(length - 2))

    # Make sure the password is compliant

    chars = set(password)

    if not chars & lowerset:

        password += choice(lowercase)

    if not chars & upperset:

        password += choice(uppercase)

    if not chars & digitset:

        password += choice(digits)

    # Pad if necessary to reach required length

    password += ''.join(choice(pool) for i in range(length - len(password)))

    return password

def zeropad(s):

    """Add zeros at the end of a string in order to make its length

       a multiple of 16."""

    npad = 16 - len(s) % 16

    return s + '\x00' * npad

def encrypt(plaintext):

    # Make sure key is 32 bytes long

    key = sha256(settings.SECRET_KEY).digest()

    aes = AES.new(key)

    enc = aes.encrypt(zeropad(plaintext))

    return b64encode(enc)

def get_vm(server_id, user_id, for_update=False, non_deleted=False,

           non_suspended=False, prefetch_related=None):

    """Find a VirtualMachine instance based on ID and owner."""

    try:

        server_id = int(server_id)

        servers = VirtualMachine.objects

        if for_update:

            servers = servers.select_for_update()

        if prefetch_related is not None:

            servers = servers.prefetch_related(prefetch_related)

        vm = servers.get(id=server_id, userid=user_id)

        if non_deleted and vm.deleted:

            raise faults.BadRequest("Server has been deleted.")

        if non_suspended and vm.suspended:

            raise faults.Forbidden("Administratively Suspended VM")

        return vm

    except ValueError:

        raise faults.BadRequest('Invalid server ID.')

    except VirtualMachine.DoesNotExist:

        raise faults.ItemNotFound('Server not found.')

def get_vm_meta(vm, key):

    """Return a VirtualMachineMetadata instance or raise ItemNotFound."""

    try:

        return VirtualMachineMetadata.objects.get(meta_key=key, vm=vm)

    except VirtualMachineMetadata.DoesNotExist:

        raise faults.ItemNotFound('Metadata key not found.')

def get_image(image_id, user_id):

    """Return an Image instance or raise ItemNotFound."""

    with image_backend(user_id) as backend:

        return backend.get_image(image_id)

def get_image_dict(image_id, user_id):

    image = {}

    img = get_image(image_id, user_id)

    image["id"] = img["id"]

    image["name"] = img["name"]

    image["format"] = img["disk_format"]

    image["checksum"] = img["checksum"]

    image["location"] = img["location"]

    checksum = image["checksum"] = img["checksum"]

    size = image["size"] = img["size"]

    image["backend_id"] = PITHOSMAP_PREFIX + "/".join([checksum, str(size)])

    properties = img.get("properties", {})

    image["metadata"] = dict((key.upper(), val)

                             for key, val in properties.items())

    return image

def get_flavor(flavor_id, include_deleted=False):

    """Return a Flavor instance or raise ItemNotFound."""

    try:

        flavor_id = int(flavor_id)

        if include_deleted:

            return Flavor.objects.get(id=flavor_id)

        else:

            return Flavor.objects.get(id=flavor_id, deleted=include_deleted)

    except (ValueError, Flavor.DoesNotExist):

        raise faults.ItemNotFound('Flavor not found.')

def get_flavor_provider(flavor):

    """Extract provider from disk template.

    Provider for `ext` disk_template is encoded in the disk template

    name, which is formed `ext_<provider_name>`. Provider is None

    for all other disk templates.

    """

    disk_template = flavor.disk_template

    provider = None

    if disk_template.startswith("ext"):

        disk_template, provider = disk_template.split("_", 1)

    return disk_template, provider

def get_network(network_id, user_id, for_update=False, non_deleted=False):

    """Return a Network instance or raise ItemNotFound."""

    try:

        network_id = int(network_id)

        objects = Network.objects.prefetch_related("subnets")

        if for_update:

            objects = objects.select_for_update()

        network = objects.get(Q(userid=user_id) | Q(public=True),

                              id=network_id)

        if non_deleted and network.deleted:

            raise faults.BadRequest("Network has been deleted.")

        return network

    except (ValueError, Network.DoesNotExist):

        raise faults.ItemNotFound('Network %s not found.' % network_id)

def get_port(port_id, user_id, for_update=False):

    """

    Return a NetworkInteface instance or raise ItemNotFound.

    """

    try:

        objects = NetworkInterface.objects

        if for_update:

            objects = objects.select_for_update()

        if not user_id:

            port = objects.get(id=port_id)

        else:

            port = objects.get(network__userid=user_id, id=port_id)

        if (port.device_owner != "vm") and for_update:

            raise faults.BadRequest('Can not update non vm port')

        return port

    except (ValueError, NetworkInterface.DoesNotExist):

        raise faults.ItemNotFound('Port not found.')

def get_security_group(sg_id):

    try:

        sg = SecurityGroup.objects.get(id=sg_id)

        return sg

    except (ValueError, SecurityGroup.DoesNotExist):

        raise faults.ItemNotFound("Not valid security group")

def get_floating_ip_by_address(userid, address, for_update=False):

    try:

        objects = IPAddress.objects

        if for_update:

            objects = objects.select_for_update()

        return objects.get(userid=userid, floating_ip=True,

                           address=address, deleted=False)

    except IPAddress.DoesNotExist:

        raise faults.ItemNotFound("Floating IP does not exist.")

def get_floating_ip_by_id(userid, floating_ip_id, for_update=False):

    try:

        objects = IPAddress.objects

        if for_update:

            objects = objects.select_for_update()

        return objects.get(id=floating_ip_id, floating_ip=True,

                           userid=userid, deleted=False)

    except IPAddress.DoesNotExist:

        raise faults.ItemNotFound("Floating IP %s does not exist." %

                                  floating_ip_id)

def allocate_ip_from_pools(pool_rows, userid, address=None, floating_ip=False):

    """Try to allocate a value from a number of pools.

    This function takes as argument a number of PoolTable objects and tries to

    allocate a value from them. If all pools are empty EmptyPool is raised.

    """

    for pool_row in pool_rows:

        pool = pool_row.pool

        try:

            value = pool.get(value=address)

            pool.save()

            subnet = pool_row.subnet

            ipaddress = IPAddress.objects.create(subnet=subnet,

                                                 network=subnet.network,

                                                 userid=userid,

                                                 address=value,

                                                 floating_ip=floating_ip)

            return ipaddress

        except pools.EmptyPool:

            pass

    raise pools.EmptyPool("No more IP addresses available on pools %s" %

                          pool_rows)

def allocate_ip(network, userid, address=None, floating_ip=False):

    """Try to allocate an IP from networks IP pools."""

    ip_pools = IPPoolTable.objects.select_for_update()\

        .filter(subnet__network=network)

    try:

        return allocate_ip_from_pools(ip_pools, userid, address=address,

                                      floating_ip=floating_ip)

    except pools.EmptyPool:

        raise faults.Conflict("No more IP addresses available on network %s"

                              % network.id)

    except pools.ValueNotAvailable:

        raise faults.Conflict("IP address %s is already used." % address)

    except pools.InvalidValue:

        raise faults.BadRequest("Address %s does not belong to network %s" %

                                (address, network.id))

def allocate_public_ip(userid, floating_ip=False, backend=None):

    """Try to allocate a public or floating IP address.

    Try to allocate a a public IPv4 address from one of the available networks.

    If 'floating_ip' is set, only networks which are floating IP pools will be

    used and the IPAddress that will be created will be marked as a floating

    IP. If 'backend' is set, only the networks that exist in this backend will

    be used.

    """

    ip_pool_rows = IPPoolTable.objects.select_for_update()\

        .prefetch_related("subnet__network")\

        .filter(subnet__deleted=False)\

        .filter(subnet__network__public=True)\

        .filter(subnet__network__drained=False)

    if floating_ip:

        ip_pool_rows = ip_pool_rows\

            .filter(subnet__network__floating_ip_pool=True)

    if backend is not None:

        ip_pool_rows = ip_pool_rows\

            .filter(subnet__network__backend_networks__backend=backend)

    try:

        return allocate_ip_from_pools(ip_pool_rows, userid,

                                      floating_ip=floating_ip)

    except pools.EmptyPool:

        ip_type = "floating" if floating_ip else "public"

        log_msg = "Failed to allocate a %s IP. Reason:" % ip_type

        if ip_pool_rows:

            log_msg += " No network exists."

        else:

            log_msg += " All network are full."

        if backend is not None:

            log_msg += " Backend: %s" % backend

        log.error(log_msg)

        exception_msg = "Can not allocate a %s IP address." % ip_type

        raise faults.ServiceUnavailable(exception_msg)

def backend_has_free_public_ip(backend):

    """Check if a backend has a free public IPv4 address."""

    ip_pool_rows = IPPoolTable.objects.select_for_update()\

        .filter(subnet__network__public=True)\

        .filter(subnet__network__drained=False)\

        .filter(subnet__deleted=False)\

        .filter(subnet__network__backend_networks__backend=backend)

    for pool_row in ip_pool_rows:

        pool = pool_row.pool

        if pool.empty():

            continue

        else:

            return True

def backend_public_networks(backend):

    return Network.objects.filter(deleted=False, public=True,

                                  backend_networks__backend=backend)

def get_vm_nic(vm, nic_id):

    """Get a VMs NIC by its ID."""

    try:

        return vm.nics.get(id=nic_id)

    except NetworkInterface.DoesNotExist:

        raise faults.ItemNotFound("NIC '%s' not found" % nic_id)

def get_nic(nic_id):

    try:

        return NetworkInterface.objects.get(id=nic_id)

    except NetworkInterface.DoesNotExist:

        raise faults.ItemNotFound("NIC '%s' not found" % nic_id)

def render_metadata(request, metadata, use_values=False, status=200):

    if request.serialization == 'xml':

        data = render_to_string('metadata.xml', {'metadata': metadata})

    else:

        if use_values:

            d = {'metadata': {'values': metadata}}

        else:

            d = {'metadata': metadata}

        data = json.dumps(d)

    return HttpResponse(data, status=status)

def render_meta(request, meta, status=200):

    if request.serialization == 'xml':

        key, val = meta.items()[0]

        data = render_to_string('meta.xml', dict(key=key, val=val))

    else:

        data = json.dumps(dict(meta=meta))

    return HttpResponse(data, status=status)

def verify_personality(personality):

    """Verify that a a list of personalities is well formed"""

    if len(personality) > settings.MAX_PERSONALITY:

        raise faults.OverLimit("Maximum number of personalities"

                               " exceeded")

    for p in personality:

        # Verify that personalities are well-formed

        try:

            assert isinstance(p, dict)

            keys = set(p.keys())

            allowed = set(['contents', 'group', 'mode', 'owner', 'path'])

            assert keys.issubset(allowed)

            contents = p['contents']

            if len(contents) > settings.MAX_PERSONALITY_SIZE:

                # No need to decode if contents already exceed limit

                raise faults.OverLimit("Maximum size of personality exceeded")

            if len(b64decode(contents)) > settings.MAX_PERSONALITY_SIZE:

                raise faults.OverLimit("Maximum size of personality exceeded")

        except AssertionError:

            raise faults.BadRequest("Malformed personality in request")

def values_from_flavor(flavor):

    """Get Ganeti connectivity info from flavor type.

    If link or mac_prefix equals to "pool", then the resources

    are allocated from the corresponding Pools.

    """

    try:

        flavor = Network.FLAVORS[flavor]

    except KeyError:

        raise faults.BadRequest("Unknown network flavor")

    mode = flavor.get("mode")

    link = flavor.get("link")

    if link == "pool":

        link = allocate_resource("bridge")

    mac_prefix = flavor.get("mac_prefix")

    if mac_prefix == "pool":

        mac_prefix = allocate_resource("mac_prefix")

    tags = flavor.get("tags")

    return mode, link, mac_prefix, tags

def allocate_resource(res_type):

    table = get_pool_table(res_type)

    pool = table.get_pool()

    value = pool.get()

    pool.save()

    return value

def release_resource(res_type, value):

    table = get_pool_table(res_type)

    pool = table.get_pool()

    pool.put(value)

    pool.save()

def get_pool_table(res_type):

    if res_type == "bridge":

        return BridgePoolTable

    elif res_type == "mac_prefix":

        return MacPrefixPoolTable

    else:

        raise Exception("Unknown resource type")

def get_existing_users():

    """

    Retrieve user ids stored in cyclades user agnostic models.

    """

    # also check PublicKeys a user with no servers/networks exist

    from synnefo.userdata.models import PublicKeyPair

    from synnefo.db.models import VirtualMachine, Network

    keypairusernames = PublicKeyPair.objects.filter().values_list('user',

                                                                  flat=True)

    serverusernames = VirtualMachine.objects.filter().values_list('userid',

                                                                  flat=True)

    networkusernames = Network.objects.filter().values_list('userid',

                                                            flat=True)

    return set(list(keypairusernames) + list(serverusernames) +

               list(networkusernames))

def vm_to_links(vm_id):

    href = join_urls(SERVERS_URL, str(vm_id))

    return [{"rel": rel, "href": href} for rel in ("self", "bookmark")]

def network_to_links(network_id):

    href = join_urls(NETWORKS_URL, str(network_id))

    return [{"rel": rel, "href": href} for rel in ("self", "bookmark")]

def flavor_to_links(flavor_id):

    href = join_urls(FLAVORS_URL, str(flavor_id))

    return [{"rel": rel, "href": href} for rel in ("self", "bookmark")]

def image_to_links(image_id):

    href = join_urls(IMAGES_URL, str(image_id))

    links = [{"rel": rel, "href": href} for rel in ("self", "bookmark")]

    links.append({"rel": "alternate",

                  "href": join_urls(IMAGES_PLANKTON_URL, str(image_id))})

    return links

def start_action(vm, action, jobId):

    vm.action = action

    vm.backendjobid = jobId

    vm.backendopcode = None

    vm.backendjobstatus = None

    vm.backendlogmsg = None

    vm.save()