Synnefo

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

#

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# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

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from functools import wraps

from contextlib import contextmanager

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

from synnefo.api.faults import OverLimit

from synnefo.settings import CYCLADES_USE_QUOTAHOLDER

if CYCLADES_USE_QUOTAHOLDER:

    from synnefo.settings import (CYCLADES_QUOTAHOLDER_URL,

                                  CYCLADES_QUOTAHOLDER_TOKEN,

                                  CYCLADES_QUOTAHOLDER_POOLSIZE)

    from synnefo.lib.quotaholder import QuotaholderClient

else:

    from synnefo.settings import (VMS_USER_QUOTA, MAX_VMS_PER_USER,

                                  NETWORKS_USER_QUOTA, MAX_NETWORKS_PER_USER)

from synnefo.lib.quotaholder.api import (NoCapacityError, NoQuantityError,

                                         NoEntityError, CallError)

import logging

log = logging.getLogger(__name__)

class DummySerial(QuotaHolderSerial):

    accepted = True

    rejected = True

    pending = True

    id = None

    def save(*args, **kwargs):

        pass

class DummyQuotaholderClient(object):

    def issue_commission(self, **commission_info):

        provisions = commission_info["provisions"]

        userid = commission_info["target"]

        for provision in provisions:

            entity, resource, size = provision

            if resource == "cyclades.vm" and size > 0:

                user_vms = VirtualMachine.objects.filter(userid=userid,

                                                         deleted=False).count()

                user_vm_limit = VMS_USER_QUOTA.get(userid, MAX_VMS_PER_USER)

                log.debug("Users VMs %s User Limits %s", user_vms,

                          user_vm_limit)

                if user_vms + size > user_vm_limit:

                    raise NoQuantityError(source='cyclades',

                                          target=userid,

                                          resource=resource,

                                          requested=size,

                                          current=user_vms,

                                          limit=user_vm_limit)

            if resource == "cyclades.network.private" and size > 0:

                user_networks = Network.objects.filter(userid=userid,

                                                       deleted=False).count()

                user_network_limit =\

                    NETWORKS_USER_QUOTA.get(userid, MAX_NETWORKS_PER_USER)

                if user_networks + size > user_network_limit:

                    raise NoQuantityError(source='cyclades',

                                          target=userid,

                                          resource=resource,

                                          requested=size,

                                          current=user_networks,

                                          limit=user_network_limit)

        return None

    def accept_commission(self, *args, **kwargs):

        pass

    def reject_commission(self, *args, **kwargs):

        pass

    def get_pending_commissions(self, *args, **kwargs):

        return []

@contextmanager

def get_quota_holder():

    """Context manager for using a QuotaHolder."""

    if CYCLADES_USE_QUOTAHOLDER:

        quotaholder = QuotaholderClient(CYCLADES_QUOTAHOLDER_URL,

                                        token=CYCLADES_QUOTAHOLDER_TOKEN,

                                        poolsize=CYCLADES_QUOTAHOLDER_POOLSIZE)

    else:

        quotaholder = DummyQuotaholderClient()

    try:

        yield quotaholder

    finally:

        pass

def uses_commission(func):

    """Decorator for wrapping functions that needs commission.

    All decorated functions must take as first argument the `serials` list in

    order to extend them with the needed serial numbers, as return by the

    Quotaholder

    On successful competition of the decorated function, all serials are

    accepted to the quotaholder, otherwise they are rejected.

    """

    @wraps(func)

    def wrapper(*args, **kwargs):

        try:

            serials = []

            ret = func(serials, *args, **kwargs)

            if serials:

                accept_commission(serials)

            return ret

        except CallError:

            log.exception("Unexpected error")

            raise

        except:

            if serials:

                reject_commission(serials=serials)

            raise

    return wrapper

## FIXME: Wrap the following two functions inside transaction ?

def accept_commission(serials, update_db=True):

    """Accept a list of pending commissions.

    @param serials: List of QuotaHolderSerial objects

    """

    if update_db:

        for s in serials:

            if s.pending:

                s.accepted = True

                s.save()

    with get_quota_holder() as qh:

        qh.accept_commission(context={},

                             clientkey='cyclades',

                             serials=[s.serial for s in serials])

def reject_commission(serials, update_db=True):

    """Reject a list of pending commissions.

    @param serials: List of QuotaHolderSerial objects

    """

    if update_db:

        for s in serials:

            if s.pending:

                s.rejected = True

                s.save()

    with get_quota_holder() as qh:

        qh.reject_commission(context={},

                             clientkey='cyclades',

                             serials=[s.serial for s in serials])

def issue_commission(**commission_info):

    """Issue a new commission to the quotaholder.

    Issue a new commission to the quotaholder, and create the

    corresponing QuotaHolderSerial object in DB.

    """

    with get_quota_holder() as qh:

        try:

            serial = qh.issue_commission(**commission_info)

        except (NoCapacityError, NoQuantityError) as e:

            msg, details = render_quotaholder_exception(e)

            raise OverLimit(msg, details=details)

        except CallError as e:

            log.exception("Unexpected error")

            raise

    if serial:

        return QuotaHolderSerial.objects.create(serial=serial)

    elif not CYCLADES_USE_QUOTAHOLDER:

        return DummySerial()

    else:

        raise Exception("No serial")

# Wrapper functions for issuing commissions for each resource type.  Each

# functions creates the `commission_info` dictionary as expected by the

# `issue_commision` function. Commissions for deleting a resource, are the same

# as for creating the same resource, but with negative resource sizes.

def issue_vm_commission(user, flavor, delete=False):

    resources = get_server_resources(flavor)

    commission_info = create_commission(user, resources, delete)

    return issue_commission(**commission_info)

def get_server_resources(flavor):

    return {'vm': 1,

            'cpu': flavor.cpu,

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

            # 'public_ip': 1,

            #'disk_template': flavor.disk_template,

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

def issue_network_commission(user, delete=False):

    resources = get_network_resources()

    commission_info = create_commission(user, resources, delete)

    return issue_commission(**commission_info)

def get_network_resources():

    return {"network.private": 1}

def invert_resources(resources_dict):

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

def create_commission(user, resources, delete=False):

    if delete:

        resources = invert_resources(resources)

    provisions = [('cyclades', 'cyclades.' + r, s)

                  for r, s in resources.items()]

    return {"context": {},

            "target": user,

            "key": "1",

            "clientkey": "cyclades",

            #"owner":      "",

            #"ownerkey":   "1",

            "name": "",

            "provisions": provisions}

##

## Reconcile pending commissions

##

def accept_commissions(accepted):

    with get_quota_holder() as qh:

        qh.accept_commission(context={},

                             clientkey='cyclades',

                             serials=accepted)

def reject_commissions(rejected):

    with get_quota_holder() as qh:

            qh.reject_commission(context={},

                                 clientkey='cyclades',

                                 serials=rejected)

def fix_pending_commissions():

    (accepted, rejected) = resolve_pending_commissions()

    with get_quota_holder() as qh:

        if accepted:

            qh.accept_commission(context={},

                                 clientkey='cyclades',

                                 serials=accepted)

        if rejected:

            qh.reject_commission(context={},

                                 clientkey='cyclades',

                                 serials=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(accepted=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():

    with get_quota_holder() as qh:

        pending_serials = qh.get_pending_commissions(context={},

                                                     clientkey='cyclades')

    return pending_serials

def render_quotaholder_exception(e):

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

                     "cpu": "CPU",

                     "ram": "RAM",

                     "network.private": "Private Network"}

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

    try:

        resource = resource_name[res]

    except KeyError:

        resource = res

    requested = e.requested

    current = e.current

    limit = e.limit

    msg = "Resource Limit Exceeded for your account."

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

              " Current value: %s, Limit: %s, Requested: %s"\

              % (resource, current, limit, requested)

    return msg, details