Synnefo

# Copyright 2012, 2013 GRNET S.A. All rights reserved.

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from django.utils import simplejson as json

from django.db import transaction

from snf_django.lib.api import faults

from synnefo.db.models import QuotaHolderSerial, VirtualMachine, Network

from synnefo.settings import (CYCLADES_SERVICE_TOKEN as ASTAKOS_TOKEN,

                              ASTAKOS_BASE_URL)

from astakosclient import AstakosClient

from astakosclient.errors import AstakosClientException, QuotaLimit

from functools import wraps

import logging

log = logging.getLogger(__name__)

DEFAULT_SOURCE = 'system'

RESOURCES = [

    "cyclades.vm",

    "cyclades.cpu",

    "cyclades.disk",

    "cyclades.ram",

    "cyclades.network.private"

]

class Quotaholder(object):

    _object = None

    @classmethod

    def get(cls):

        if cls._object is None:

            cls._object = AstakosClient(

                ASTAKOS_BASE_URL,

                use_pool=True,

                logger=log)

        return cls._object

def handle_astakosclient_error(func):

    """Decorator for converting astakosclient errors to 500."""

    @wraps(func)

    def wrapper(*args, **kwargs):

        try:

            return func(*args, **kwargs)

        except AstakosClientException:

            log.exception("Unexpected error")

            raise faults.InternalServerError("Unexpected error")

    return wrapper

@handle_astakosclient_error

def issue_commission(user, source, provisions,

                     force=False, auto_accept=False):

    """Issue a new commission to the quotaholder.

    Issue a new commission to the quotaholder, and create the

    corresponing QuotaHolderSerial object in DB.

    """

    qh = Quotaholder.get()

    try:

        serial = qh.issue_one_commission(ASTAKOS_TOKEN,

                                         user, source, provisions,

                                         force=force, auto_accept=auto_accept)

    except QuotaLimit as e:

        msg, details = render_overlimit_exception(e)

        raise faults.OverLimit(msg, details=details)

    if serial:

        return QuotaHolderSerial.objects.create(serial=serial)

    else:

        raise Exception("No serial")

def accept_commissions(accepted, strict=True):

    return resolve_commissions(accept=accepted, strict=strict)

def reject_commissions(rejected, strict=True):

    return resolve_commissions(reject=rejected, strict=strict)

@handle_astakosclient_error

def resolve_commissions(accept=None, reject=None, strict=True):

    if accept is None:

        accept = []

    if reject is None:

        reject = []

    qh = Quotaholder.get()

    response = qh.resolve_commissions(ASTAKOS_TOKEN, accept, reject)

    if strict:

        failed = response["failed"]

        if failed:

            log.error("Unexpected error while resolving commissions: %s",

                      failed)

    return response

def fix_pending_commissions():

    (accepted, rejected) = resolve_pending_commissions()

    resolve_commissions(accept=accepted, reject=rejected)

def resolve_pending_commissions():

    """Resolve quotaholder pending commissions.

    Get pending commissions from the quotaholder and resolve them

    to accepted and rejected, according to the state of the

    QuotaHolderSerial DB table. A pending commission in the quotaholder

    can exist in the QuotaHolderSerial table and be either accepted or

    rejected, or can not exist in this table, so it is rejected.

    """

    qh_pending = get_quotaholder_pending()

    if not qh_pending:

        return ([], [])

    qh_pending.sort()

    min_ = qh_pending[0]

    serials = QuotaHolderSerial.objects.filter(serial__gte=min_, pending=False)

    accepted = serials.filter(accept=True).values_list('serial', flat=True)

    accepted = filter(lambda x: x in qh_pending, accepted)

    rejected = list(set(qh_pending) - set(accepted))

    return (accepted, rejected)

def get_quotaholder_pending():

    qh = Quotaholder.get()

    pending_serials = qh.get_pending_commissions(ASTAKOS_TOKEN)

    return pending_serials

def render_overlimit_exception(e):

    resource_name = {"vm": "Virtual Machine",

                     "cpu": "CPU",

                     "ram": "RAM",

                     "network.private": "Private Network"}

    details = json.loads(e.details)

    data = details['overLimit']['data']

    usage = data["usage"]

    limit = data["limit"]

    available = limit - usage

    provision = data['provision']

    requested = provision['quantity']

    resource = provision['resource']

    res = resource.replace("cyclades.", "", 1)

    try:

        resource = resource_name[res]

    except KeyError:

        resource = res

    msg = "Resource Limit Exceeded for your account."

    details = "Limit for resource '%s' exceeded for your account."\

              " Available: %s, Requested: %s"\

              % (resource, available, requested)

    return msg, details

@transaction.commit_manually

def issue_and_accept_commission(resource, delete=False):

    """Issue and accept a commission to Quotaholder.

    This function implements the Commission workflow, and must be called

    exactly after and in the same transaction that created/updated the

    resource. The workflow that implements is the following:

    0) Resolve previous unresolved commission if exists

    1) Issue commission and get a serial

    2) Store the serial in DB and mark is as one to accept

    3) Correlate the serial with the resource

    4) COMMIT!

    5) Accept commission to QH (reject if failed until 5)

    6) Mark serial as resolved

    7) COMMIT!

    """

    previous_serial = resource.serial

    if previous_serial is not None and not previous_serial.resolved:

        if previous_serial.pending:

            msg = "Issuing commission for resource '%s' while previous serial"\

                  " '%s' is still pending." % (resource, previous_serial)

            raise Exception(msg)

        elif previous_serial.accept:

            accept_commissions(accepted=[previous_serial.serial], strict=False)

        else:

            reject_commissions(rejected=[previous_serial.serial], strict=False)

        previous_serial.resolved = True

    try:

        # Convert resources in the format expected by Quotaholder

        qh_resources = prepare_qh_resources(resource)

        if delete:

            qh_resources = reverse_quantities(qh_resources)

        # Issue commission and get the assigned serial

        serial = issue_commission(resource.userid, DEFAULT_SOURCE,

                                  qh_resources)

    except:

        transaction.rollback()

        raise

    try:

        # Mark the serial as one to accept. This step is necessary for

        # reconciliation

        serial.pending = False

        serial.accept = True

        serial.save()

        # Associate serial with the resource

        resource.serial = serial

        resource.save()

        # Commit transaction in the DB! If this commit succeeds, then the

        # serial is created in the DB with all the necessary information to

        # reconcile commission

        transaction.commit()

    except:

        transaction.rollback()

        serial.pending = False

        serial.accept = False

        serial.save()

        transaction.commit()

        raise

    if serial.accept:

        # Accept commission to Quotaholder

        accept_commissions(accepted=[serial.serial])

    else:

        reject_commissions(rejected=[serial.serial])

    # Mark the serial as resolved, indicating that no further actions are

    # needed for this serial

    serial.resolved = True

    serial.save()

    transaction.commit()

    return serial

def prepare_qh_resources(resource):

    if isinstance(resource, VirtualMachine):

        flavor = resource.flavor

        return {'cyclades.vm': 1,

                'cyclades.cpu': flavor.cpu,

                'cyclades.disk': 1073741824 * flavor.disk,  # flavor.disk in GB

                # 'public_ip': 1,

                #'disk_template': flavor.disk_template,

                'cyclades.ram': 1048576 * flavor.ram}  # flavor.ram is in MB

    elif isinstance(resource, Network):

        return {"cyclades.network.private": 1}

    else:

        raise ValueError("Unknown Resource '%s'" % resource)

def reverse_quantities(resources):

    return dict((r, -s) for r, s in resources.items())