ifupdown2/ifupdown/statemanager.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014-2017 Cumulus Networks, Inc. All rights reserved.
   4 # Author: Roopa Prabhu, roopa@cumulusnetworks.com
   5 #
   6 # stateManager --
   7 #    interface state manager
   8 #
   9
  10 import os
  11 import cPickle
  12 import logging
  13
  14 try:
  15     from ifupdown2.ifupdown.iface import *
  16
  17     import ifupdown2.ifupdown.exceptions as exceptions
  18 except ImportError:
  19     from ifupdown.iface import *
  20
  21     import ifupdown.exceptions as exceptions
  22
  23
  24 class pickling():
  25     """ class with helper methods for pickling/unpickling iface objects """
  26
  27     @classmethod
  28     def save(cls, filename, list_of_objects):
  29         """ pickle a list of iface objects """
  30         try:
  31             with open(filename, 'w') as f:
  32                 for obj in list_of_objects:
  33                     cPickle.dump(obj, f, cPickle.HIGHEST_PROTOCOL)
  34         except:
  35             raise
  36
  37     @classmethod
  38     def save_obj(cls, f, obj):
  39         """ pickle iface object """
  40         try:
  41             cPickle.dump(obj, f, cPickle.HIGHEST_PROTOCOL)
  42         except:
  43             raise
  44
  45     @classmethod
  46     def load(cls, filename):
  47         """ load picked iface object """
  48         with open(filename, 'r') as f:
  49             while True:
  50                 try: yield cPickle.load(f)
  51                 except EOFError: break
  52                 except: raise
  53
  54 class stateManager():
  55     """ state manager for managing ifupdown iface obj state
  56
  57     ifupdown2 has to maitain old objects for down operation on
  58     interfaces. ie to down or delete old configuration.
  59
  60     This class uses pickle to store iface objects.
  61
  62     """
  63
  64     state_dir = '/var/tmp/network/'
  65     """directory where the state file is stored """
  66
  67     state_filename = 'ifstatenew'
  68     """name of the satefile """
  69
  70     state_rundir = '/run/network/'
  71     """name of the state run dir """
  72
  73     state_runlockfile = 'ifstatelock'
  74     """name of the state run lock file """
  75
  76     def __init__(self):
  77         """ Initializes statemanager internal state
  78
  79         which includes a dictionary of last pickled iface objects
  80         """
  81         self.ifaceobjdict = OrderedDict()
  82         self.logger = logging.getLogger('ifupdown.' +
  83                     self.__class__.__name__)
  84         if not os.path.exists(self.state_dir):
  85             os.mkdir(self.state_dir)
  86         if not os.path.exists(self.state_rundir):
  87             os.mkdir(self.state_rundir)
  88         self.state_file = self.state_dir + self.state_filename
  89
  90     def save_ifaceobj(self, ifaceobj):
  91         self.ifaceobjdict.setdefault(ifaceobj.name,
  92                             []).append(ifaceobj)
  93
  94     def read_saved_state(self, filename=None):
  95         """This member function reads saved iface objects
  96
  97         Kwargs:
  98             filename (str): name of the state file
  99         """
 100
 101         pickle_filename = filename
 102         if not pickle_filename:
 103             pickle_filename = self.state_file
 104         if not os.path.exists(pickle_filename):
 105             return
 106         for ifaceobj in pickling.load(pickle_filename):
 107             self.save_ifaceobj(ifaceobj)
 108
 109     def get_ifaceobjs(self, ifacename):
 110         return self.ifaceobjdict.get(ifacename)
 111
 112     def ifaceobj_sync(self, ifaceobj, op):
 113         """This member function sync's new obj state to old statemanager state
 114
 115         Args:
 116             ifaceobj (object): new iface object
 117             op (str): ifupdown operation
 118         """
 119
 120         self.logger.debug('%s: statemanager sync state %s'
 121                           %(ifaceobj.name, op))
 122         old_ifaceobjs = self.ifaceobjdict.get(ifaceobj.name)
 123         if 'up' in op:
 124             if not old_ifaceobjs:
 125                 self.ifaceobjdict[ifaceobj.name] = [ifaceobj]
 126             else:
 127                 # If it matches any of the object, return
 128                 if any(o.compare(ifaceobj) for o in old_ifaceobjs):
 129                     return
 130                 # If it does not match any of the objects, and if
 131                 # all objs in the list came from the pickled file,
 132                 # then reset the list and add this object as a fresh one,
 133                 # else append to the list
 134                 if old_ifaceobjs[0].flags & iface._PICKLED:
 135                     del self.ifaceobjdict[ifaceobj.name]
 136                     self.ifaceobjdict[ifaceobj.name] = [ifaceobj]
 137                 else:
 138                     self.ifaceobjdict[ifaceobj.name].append(ifaceobj)
 139         elif 'down' in op:
 140             # If down of object successfull, delete object from state manager
 141             if not old_ifaceobjs:
 142                 return
 143             if ifaceobj.status != ifaceStatus.SUCCESS:
 144                 return
 145             # If it matches any of the object, return
 146             oidx = 0
 147             for o in old_ifaceobjs:
 148                 if o.compare(ifaceobj):
 149                     old_ifaceobjs.pop(oidx)
 150                     if not len(old_ifaceobjs):
 151                         del self.ifaceobjdict[ifaceobj.name]
 152                     return
 153                 oidx += 1
 154
 155     def save_state(self):
 156         """ saves state (ifaceobjects) to persistent state file """
 157
 158         try:
 159             with open(self.state_file, 'w') as f:
 160                 if not len(self.ifaceobjdict):
 161                     f.truncate(0)
 162                     return
 163                 self.logger.debug('saving state ..')
 164                 for ifaceobjs in self.ifaceobjdict.values():
 165                     [pickling.save_obj(f, i) for i in ifaceobjs]
 166             open('%s/%s' %(self.state_rundir, self.state_runlockfile), 'w').close()
 167         except:
 168             raise
 169
 170     def dump_pretty(self, ifacenames, format='native'):
 171         if not ifacenames:
 172             ifacenames = self.ifaceobjdict.keys()
 173         for i in ifacenames:
 174             ifaceobjs = self.get_ifaceobjs(i)
 175             if not ifaceobjs:
 176                 continue
 177             for ifaceobj in ifaceobjs:
 178                 if format == 'json':
 179                     ifaceobj.dump_json()
 180                 else:
 181                     ifaceobj.dump_pretty()
 182
 183     def dump(self, ifacenames=None):
 184         self.logger.debug('statemanager iface state:')
 185         if ifacenames:
 186             for i in ifacenames:
 187                 ifaceobj = self.ifaces.get(i)
 188                 if ifaceobj is None:
 189                     raise exceptions.ifaceNotFoundError('ifname %s'
 190                                                         % i + ' not found')
 191                 ifaceobj.dump(self.logger)
 192         else:
 193             for ifacename, ifaceobjs in self.ifaceobjdict.items():
 194                 [i.dump(self.logger) for i in ifaceobjs]
 195
 196 statemanager_api = stateManager()
 197
 198 def reset():
 199     global statemanager_api
 200     statemanager_api = stateManager()