rwcal/plugins/vala/rwcal_cloudsim/rift/rwcal/cloudsim/net.py

   1
   2 #
   3 #   Copyright 2016 RIFT.IO Inc
   4 #
   5 #   Licensed under the Apache License, Version 2.0 (the "License");
   6 #   you may not use this file except in compliance with the License.
   7 #   You may obtain a copy of the License at
   8 #
   9 #       http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 #   Unless required by applicable law or agreed to in writing, software
  12 #   distributed under the License is distributed on an "AS IS" BASIS,
  13 #   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 #   See the License for the specific language governing permissions and
  15 #   limitations under the License.
  16 #
  17
  18 import collections
  19
  20 import netifaces
  21
  22 from . import shell
  23
  24
  25 class VirshError(Exception):
  26     pass
  27
  28
  29 def create(network, ip_interface=None):
  30     """ Create, assign ip and bring up a bridge interface
  31
  32     Arguments:
  33         network - The network name
  34         ip_interface - An ipaddress.IPv4Interface instance
  35     """
  36     bridge_add(network)
  37     if ip_interface is not None:
  38         bridge_addr(
  39                 network,
  40                 str(ip_interface),
  41                 str(ip_interface.network.broadcast_address),
  42                 )
  43     bridge_up(network)
  44
  45
  46 def delete(network):
  47     bridge_down(network)
  48     bridge_remove(network)
  49
  50
  51 def bridge_add(network):
  52     shell.command("/usr/sbin/brctl addbr {network}".format(network=network))
  53
  54
  55 def bridge_remove(network):
  56     shell.command("/usr/sbin/brctl delbr {network}".format(network=network))
  57
  58
  59 def bridge_addr(network, addr, broadcast):
  60     cmd = "ip addr add {addr} broadcast {broadcast} dev {network}"
  61     shell.command(cmd.format(addr=addr, broadcast=broadcast, network=network))
  62
  63
  64 def bridge_exists(network):
  65     return network in netifaces.interfaces()
  66
  67
  68 def bridge_down(network):
  69     shell.command('ip link set {network} down'.format(network=network))
  70
  71
  72 def bridge_up(network):
  73     shell.command('ip link set {network} up'.format(network=network))
  74
  75
  76 def bridge_addresses(network):
  77     try:
  78         address = netifaces.ifaddresses(network)[netifaces.AF_INET][0]
  79
  80     except KeyError:
  81         raise ValueError('unable to find subnet for {}'.format(network))
  82
  83     cls = collections.namedtuple('BridgeAddresses', 'addr netmask broadcast')
  84     return cls(**address)
  85
  86
  87 VirshNetwork = collections.namedtuple(
  88     'VirshNetwork', 'name state autostart persistant')
  89
  90
  91 def virsh_list_networks():
  92     lines = shell.command('virsh net-list --all')
  93     if len(lines) < 2:
  94         raise Exception("Expected two lines from virsh net-list output")
  95
  96     network_lines = lines[2:]
  97     virsh_networks = []
  98     for line in network_lines:
  99         if not line.strip():
 100             continue
 101
 102         (name, state, autostart, persistant) = line.split()
 103         virsh_networks.append(
 104                 VirshNetwork(name, state, autostart, persistant)
 105                 )
 106
 107     return virsh_networks
 108
 109
 110 def virsh_list_network_names():
 111     virsh_networks = virsh_list_networks()
 112     return [n.name for n in virsh_networks]
 113
 114
 115 def virsh_is_active(network_name):
 116     virsh_networks = virsh_list_networks()
 117     for network in virsh_networks:
 118         if network.name == network_name:
 119             return network.state == "active"
 120
 121     raise VirshError("Did not find virsh network %s" % network_name)
 122
 123
 124 def virsh_define_default():
 125     shell.command('virsh net-define /usr/share/libvirt/networks/default.xml')
 126
 127
 128 def virsh_start(network_name):
 129     shell.command('virsh net-start %s' % network_name)
 130
 131
 132 def virsh_initialize_default():
 133     if "default" not in virsh_list_network_names():
 134         virsh_define_default()
 135
 136     if virsh_is_active("default"):
 137         if bridge_exists("virbr0"):
 138             bridge_down("virbr0")
 139
 140         virsh_destroy("default")
 141
 142     virsh_start("default")
 143
 144
 145 def virsh_destroy(network_name):
 146     shell.command('virsh net-destroy %s' % network_name)
 147