ifupdown/statemanager.py

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