lease.py

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# -*- coding: utf-8 -*-
# @COPYRIGHT_begin
#
# Copyright [2010-2014] Institute of Nuclear Physics PAN, Krakow, Poland
#
# Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.
#
# @COPYRIGHT_end

##
# @package src.cm.views.user.network
# @author Maciej Nabożny <mn@mnabozny.pl>
# 
# 
# Database model describing single lease or mirco-network (depends on networking
# model) for VM
# 
from django.db import models
from django.template import loader, Context
from netaddr import IPNetwork, IPAddress

import socket
import libvirt

from cm.utils.exception import CMException
from cm.utils import log
from cm.settings import DNS_DOMAIN


class Lease(models.Model):
    address = models.CharField(max_length=20)
    user_network = models.ForeignKey('UserNetwork')
    vm = models.ForeignKey('VM', null=True, blank=True)

    class Meta:
        app_label = 'cm'

    def __unicode__(self):
        return self.address

    @property
    def dict(self):
        d = {}
        d['lease_id'] = self.id
        d['address'] = self.vm_address
        d['user_network_id'] = self.user_network.id
        if self.vm:
            d['vm'] = self.vm.id
        else:
            d['vm'] = None
        d['user_id'] = self.user_network.user.id
        try:
            d['public_ip'] = self.publicip_set.all()[0].dict
        except:
            d['public_ip'] = ''

        return d

    @property
    def node_address(self):
        network = IPNetwork('%s/30' % self.address)
        return str(network.network + 1)

    @property
    def vm_address(self):
        network = IPNetwork('%s/30' % self.address)
        return str(network.network + 2)

    @property
    def cm_address(self):
        if self.vm == None or self.vm.node == None:
            raise CMException('lease_not_attached')
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect((self.vm.node.address, 22))
        return s.getsockname()[0]

    @property
    def domain_name(self):
        return DNS_DOMAIN

    @property
    def hostname(self):
        return 'vm-%d' % self.vm.id

    @property
    def mac(self):
        ip_hex = '%08x' % IPAddress(self.address).value
        return '00:02:%s:%s:%s:%s' % (ip_hex[0:2], ip_hex[2:4], ip_hex[4:6], ip_hex[6:8])

    def attach_node(self):
        template = loader.get_template('networking/routed.xml')
        context = Context({
            'lease': self,
            'vm': self.vm
        })

        network_xml = template.render(context)
        log.debug(self.user_network.user.id, "Rendered network template:\n%s" % network_xml)
        conn = libvirt.open(self.vm.node.conn_string)
        net = conn.networkDefineXML(network_xml)
        net.create()

    ##
    # 
    #         @raises{lease_detached,CMException} Network was not defined
    #         
    def detach_node(self):
        if self.vm_id == None:
            raise CMException('lease_detached')

        # Destroy network
        try:
            conn = libvirt.open(self.vm.node.conn_string)
        except Exception, e:
            log.exception(self.user_network.user_id, "Cannot connet to libvirt: ")
            raise CMException('lease_detach')

        lv_network = None
        try:
            lv_network = conn.networkLookupByName('net-%d-%d' % (self.vm.id, self.id))
        except Exception, e:  # it's sad that network is missing, but if it was WN from init_head state farm, it's ok
            log.error(self.user_network.user_id, "Cannotfind libvirt network: %s" % str(e))
            lv_network = None

        if lv_network:
            try:
                lv_network.destroy()
                lv_network.undefine()
            except Exception, e:  # it's sad that network is missing, but if it was WN from init_head state farm, it's ok
                log.error(self.user_network.user_id, "Cannot destroy or undefine libvirt network: %s" % str(e))
                # raise CMException('lease_detach')

        # Detach public ip
        for public_lease in self.publicip_set.all():
            log.debug(self.user_network.user.id, "\t...detaching public lease %s" % public_lease.address)
            public_lease.unassign()

        conn.close()
        self.vm_id = None
        self.save()