plugins/privatebridge.py

   1 """
   2 Private Bridge configurator.
   3 """
   4
   5 import select
   6 import subprocess
   7 import time
   8 import tools
   9
  10 import logger
  11
  12 priority = 9
  13
  14 class OvsException (Exception) :
  15     def __init__(self, message="no message"):
  16         self.message = message
  17     def __repr__(self):
  18         return self.message
  19
  20 def start():
  21     logger.log('private bridge plugin starting up...')
  22
  23 def log_call_read(command, timeout=logger.default_timeout_minutes*60, poll=1):
  24     message = " ".join(command)
  25     logger.log("log_call: running command %s" % message)
  26     logger.verbose("log_call: timeout=%r s" % timeout)
  27     logger.verbose("log_call: poll=%r s" % poll)
  28     trigger = time.time()+timeout
  29     try:
  30         child = subprocess.Popen(
  31             command, bufsize=1,
  32             stdout=subprocess.PIPE, stderr=subprocess.PIPE,
  33             close_fds=True,
  34             universal_newlines=True)
  35
  36         stdout = ""
  37         while True:
  38             # see if anything can be read within the poll interval
  39             (r, w, x) = select.select([child.stdout], [], [], poll)
  40             if r:
  41                 stdout = stdout + child.stdout.read(1)
  42             # is process over ?
  43             returncode=child.poll()
  44             # yes
  45             if returncode != None:
  46                 stdout = stdout + child.stdout.read()
  47                 # child is done and return 0
  48                 if returncode == 0:
  49                     logger.log("log_call:end command (%s) completed" % message)
  50                     if stdout != "":
  51                         logger.log("log_call:stdout: %s" % stdout)
  52                     return (returncode, stdout)
  53                 # child has failed
  54                 else:
  55                     log("log_call:end command (%s) returned with code %d"
  56                         %(message, returncode))
  57                     return (returncode, stdout)
  58             # no : still within timeout ?
  59             if time.time() >= trigger:
  60                 child.terminate()
  61                 logger.log("log_call:end terminating command (%s) - exceeded timeout %d s"
  62                            %(message, timeout))
  63                 return (-2, None)
  64                 break
  65     except Exception as e:
  66         logger.log_exc("failed to run command %s -> %s" % (message, e))
  67
  68     return (-1, None)
  69
  70 ### Thierry - 23 Sept 2014
  71 # regardless of this being shipped on lxc-only or on all nodes,
  72 # it is safer to check for the availability of the ovs-vsctl command and just print
  73 # out a warning when it's not there, instead of a nasty traceback
  74 def ovs_available ():
  75     "return True if ovs-vsctl can be run"
  76     try:
  77         child = subprocess.Popen (['ovs-vsctl', '--help'])
  78         child.communicate()
  79         return True
  80     except:
  81         return False
  82
  83 def ovs_vsctl(args):
  84     return log_call_read(["ovs-vsctl"] + args)
  85
  86 def ovs_listbridge():
  87     (returncode, stdout) = ovs_vsctl(["list-br"])
  88     if (returncode != 0): raise OvsException("list-br")
  89     return stdout.split()
  90
  91 def ovs_addbridge(name):
  92     (returncode, stdout) = ovs_vsctl(["add-br", name])
  93     if (returncode != 0): raise OvsException("add-br")
  94
  95 def ovs_listports(name):
  96     (returncode, stdout) = ovs_vsctl(["list-ports", name])
  97     if (returncode != 0): raise OvsException("list-ports")
  98     return stdout.split()
  99
 100 def ovs_delbridge(name):
 101     (returncode, stdout) = ovs_vsctl(["del-br", name])
 102     if (returncode != 0): raise OvsException("del-br")
 103
 104 def ovs_addport(name, portname, type, remoteip, key):
 105     args = ["add-port", name, portname, "--", "set", "interface", portname, "type="+type]
 106     if remoteip:
 107         args = args + ["options:remote_ip=" + remoteip]
 108     if key:
 109         args = args + ["options:key=" + str(key)]
 110
 111     returncode, stdout = ovs_vsctl(args)
 112     if (returncode != 0):
 113         raise OvsException("add-port")
 114
 115 def ovs_delport(name, portname):
 116     (returncode, stdout) = ovs_vsctl(["del-port", name, portname])
 117     if (returncode != 0): raise OvsException("del-port")
 118
 119 def ensure_slicebridge_created(name, addr):
 120     bridges = ovs_listbridge()
 121     logger.log("privatebridge: current bridges = " + ",".join(bridges))
 122     if name in bridges:
 123         return
 124
 125     ovs_addbridge(name)
 126
 127     logger.log_call(["ifconfig", name, addr, "netmask", "255.0.0.0"])
 128
 129 def ensure_slicebridge_neighbors(name, sliver_id, neighbors):
 130     ports = ovs_listports(name)
 131
 132     want_ports = []
 133     for neighbor in neighbors:
 134         (neighbor_node_id, neighbor_ip) = neighbor.split("/")
 135         neighbor_node_id = int(neighbor_node_id)
 136         portname = "gre%d-%d" % (sliver_id, neighbor_node_id)
 137
 138         want_ports.append(portname)
 139
 140         if not portname in ports:
 141             ovs_addport(name, portname, "gre", neighbor_ip, sliver_id)
 142
 143     for portname in ports:
 144         if portname.startswith("gre") and (portname not in want_ports):
 145             ovs_delport(name, portname)
 146
 147 def configure_slicebridge(sliver, attributes):
 148     sliver_name = sliver['name']
 149     sliver_id = sliver['slice_id']
 150
 151     slice_bridge_name = attributes["slice_bridge_name"]
 152
 153     slice_bridge_addr = attributes.get("slice_bridge_addr", None)
 154     if not slice_bridge_addr:
 155         logger.log("privatebridge: no slice_bridge_addr for %s" % sliver_name)
 156         return
 157
 158     slice_bridge_neighbors = attributes.get("slice_bridge_neighbors", None)
 159     if not slice_bridge_neighbors:
 160         logger.log("privatebridge: no slice_bridge_neighbors for %s" % sliver_name)
 161         return
 162
 163     slice_bridge_neighbors = [x.strip() for x in slice_bridge_neighbors.split(",")]
 164
 165     ensure_slicebridge_created(slice_bridge_name, slice_bridge_addr)
 166     ensure_slicebridge_neighbors(slice_bridge_name, sliver_id, slice_bridge_neighbors)
 167
 168 def GetSlivers(data, conf = None, plc = None):
 169
 170     if not ovs_available():
 171         logger.log ("privatebridge: warning, ovs-vsctl not found - exiting")
 172         return
 173
 174     node_id = tools.node_id()
 175
 176     if 'slivers' not in data:
 177         logger.log_missing_data("privatebridge.GetSlivers", 'slivers')
 178         return
 179
 180     valid_bridges = []
 181     for sliver in data['slivers']:
 182         sliver_name = sliver['name']
 183
 184         # build a dict of attributes, because it's more convenient
 185         attributes = {}
 186         for attribute in sliver['attributes']:
 187             attributes[attribute['tagname']] = attribute['value']
 188
 189         bridge_name = attributes.get('slice_bridge_name', None)
 190         if bridge_name:
 191             configure_slicebridge(sliver, attributes)
 192             valid_bridges.append(bridge_name)
 193
 194     # now, delete the bridges that we don't want
 195     bridges = ovs_listbridge()
 196     for bridge_name in bridges:
 197         if not bridge_name.startswith("br-slice-"):
 198             # ignore ones we didn't create
 199             continue
 200
 201         if bridge_name in valid_bridges:
 202             # ignore ones we want to keep
 203             continue
 204
 205         logger.log("privatebridge: deleting unused bridge %s" % bridge_name)
 206
 207         ovs_delbridge(bridge_name)