xenserver/etc_xapi.d_plugins_openvswitch-cfg-update

   1 #!/usr/bin/env python
   2 #
   3 # xapi plugin script to update the cache of configuration items in the
   4 # ovs-vswitchd configuration that are managed in the xapi database when
   5 # integrated with Citrix management tools.
   6
   7 # Copyright (C) 2009, 2010 Nicira Networks, Inc.
   8 #
   9 # Licensed under the Apache License, Version 2.0 (the "License");
  10 # you may not use this file except in compliance with the License.
  11 # You may obtain a copy of the License at:
  12 #
  13 #     http://www.apache.org/licenses/LICENSE-2.0
  14 #
  15 # Unless required by applicable law or agreed to in writing, software
  16 # distributed under the License is distributed on an "AS IS" BASIS,
  17 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18 # See the License for the specific language governing permissions and
  19 # limitations under the License.
  20
  21 # TBD: - error handling needs to be improved.  Currently this can leave
  22 # TBD:   the system in a bad state if anything goes wrong.
  23
  24 import XenAPIPlugin
  25 import XenAPI
  26 import os
  27 import subprocess
  28 import syslog
  29
  30 vsctl="/usr/bin/ovs-vsctl"
  31 cacert_filename="/etc/openvswitch/vswitchd.cacert"
  32
  33 # Delete the CA certificate, so that we go back to boot-strapping mode
  34 def delete_cacert():
  35     try:
  36         os.remove(cacert_filename)
  37     except OSError:
  38         # Ignore error if file doesn't exist
  39         pass
  40
  41 def update(session, args):
  42     # Refresh bridge network UUIDs in case this host joined or left a pool.
  43     script = "/opt/xensource/libexec/interface-reconfigure"
  44     try:
  45         retval = subprocess.call([script, "rewrite"])
  46         if retval != 0:
  47             syslog.syslog("%s exited with status %d" % (script, retval))
  48     except OSError, e:
  49         syslog.syslog("%s: failed to execute (%s)" % (script, e.strerror))
  50
  51     pools = session.xenapi.pool.get_all()
  52     # We assume there is only ever one pool...
  53     if len(pools) == 0:
  54         raise XenAPIPlugin.Failure("NO_POOL_FOR_HOST", [])
  55     if len(pools) > 1:
  56         raise XenAPIPlugin.Failure("MORE_THAN_ONE_POOL_FOR_HOST", [])
  57     pool = session.xenapi.pool.get_record(pools[0])
  58     try:
  59         try:
  60             controller = pool["vswitch_controller"]
  61         except KeyError:
  62             # On systems older than XenServer 5.6.0, we needed to store
  63             # the key in "other_config".
  64             controller = pool["other_config"]["vSwitchController"]
  65     except KeyError, e:
  66         controller = ""
  67     currentController = vswitchCurrentController()
  68     if controller == "" and currentController != "":
  69         delete_cacert()
  70         try:
  71             emergency_reset(session, None)
  72         except:
  73             pass
  74         removeControllerCfg()
  75         return "Successfully removed controller config"
  76     elif controller != currentController:
  77         delete_cacert()
  78         try:
  79             emergency_reset(session, None)
  80         except:
  81             pass
  82         setControllerCfg(controller)
  83         return "Successfully set controller to " + controller
  84     else:
  85         return "No change to configuration"
  86
  87 def vswitchCurrentController():
  88     controller = vswitchCfgQuery(["get", "Open_vSwitch",
  89                                   ".", "managers"]).strip('[]"')
  90     if controller == "":
  91         return controller
  92     if len(controller) < 4 or controller[0:4] != "ssl:":
  93         return controller
  94     else:
  95         return controller.split(':')[1]
  96
  97 def removeControllerCfg():
  98     vswitchCfgMod(["--", "clear", "Open_vSwitch", ".", "managers",
  99                    "--", "del-ssl"])
 100
 101 def setControllerCfg(controller):
 102     # /etc/xensource/xapi-ssl.pem is mentioned twice below because it
 103     # contains both the private key and the certificate.
 104     vswitchCfgMod(["--", "clear", "Open_vSwitch", ".", "managers",
 105                    "--", "del-ssl",
 106                    "--", "--bootstrap", "set-ssl",
 107                    "/etc/xensource/xapi-ssl.pem",
 108                    "/etc/xensource/xapi-ssl.pem",
 109                    cacert_filename,
 110                    "--", "set", "Open_vSwitch", ".",
 111                    'managers="ssl:' + controller + ':6632"'])
 112
 113 def vswitchCfgQuery(action_args):
 114     cmd = [vsctl, "--timeout=5", "-vANY:console:emer"] + action_args
 115     output = subprocess.Popen(cmd, stdout=subprocess.PIPE).communicate()
 116     if len(output) == 0 or output[0] == None:
 117         output = ""
 118     else:
 119         output = output[0].strip()
 120     return output
 121
 122 def vswitchCfgMod(action_args):
 123     cmd = [vsctl, "--timeout=5", "-vANY:console:emer"] + action_args
 124     exitcode = subprocess.call(cmd)
 125     if exitcode != 0:
 126         raise XenAPIPlugin.Failure("VSWITCH_CONFIG_MOD_FAILURE",
 127                                    [ str(exitcode) , str(action_args) ])
 128
 129 def emergency_reset(session, args):
 130     cmd = [vsctl, "--timeout=5", "emer-reset"]
 131     exitcode = subprocess.call(cmd)
 132     if exitcode != 0:
 133         raise XenAPIPlugin.Failure("VSWITCH_EMER_RESET_FAILURE",
 134                                    [ str(exitcode) ])
 135
 136     return "Successfully reset configuration"
 137
 138 if __name__ == "__main__":
 139     XenAPIPlugin.dispatch({"update": update,
 140                            "emergency_reset": emergency_reset})