planetstack/ec2_observer/syncstep.py

   1 import os
   2 import base64
   3 from datetime import datetime
   4 from planetstack.config import Config
   5 from util.logger import Logger, logging
   6 from observer.steps import *
   7
   8 logger = Logger(level=logging.INFO)
   9
  10 class FailedDependency(Exception):
  11     pass
  12
  13 class SyncStep:
  14     """ A PlanetStack Sync step.
  15
  16     Attributes:
  17         psmodel        Model name the step synchronizes
  18         dependencies    list of names of models that must be synchronized first if the current model depends on them
  19     """
  20     slow=False
  21     def get_prop(prop):
  22         try:
  23             sync_config_dir = Config().sync_config_dir
  24         except:
  25             sync_config_dir = '/etc/planetstack/sync'
  26         prop_config_path = '/'.join(sync_config_dir,self.name,prop)
  27         return open(prop_config_path).read().rstrip()
  28
  29     def __init__(self, **args):
  30         """Initialize a sync step
  31            Keyword arguments:
  32                    name -- Name of the step
  33                 provides -- PlanetStack models sync'd by this step
  34         """
  35         dependencies = []
  36         self.driver = args.get('driver')
  37         self.error_map = args.get('error_map')
  38
  39         try:
  40             self.soft_deadline = int(self.get_prop('soft_deadline_seconds'))
  41         except:
  42             self.soft_deadline = 5 # 5 seconds
  43
  44         return
  45
  46     def fetch_pending(self, deletion=False):
  47         return []
  48         #return Sliver.objects.filter(ip=None)
  49
  50     def check_dependencies(self, obj, failed):
  51         for dep in self.dependencies:
  52             peer_object = getattr(obj, dep.lower())
  53             if (peer_object.pk==failed.pk):
  54                 raise FailedDependency
  55
  56     def call(self, failed=[], deletion=False):
  57         pending = self.fetch_pending(deletion)
  58         for o in pending:
  59             try:
  60                 for f in failed:
  61                     self.check_dependencies(o,f) # Raises exception if failed
  62                 if (deletion):
  63                     self.delete_record(o)
  64                     o.delete(purge=True)
  65                 else:
  66                     self.sync_record(o)
  67                     o.enacted = datetime.now() # Is this the same timezone? XXX
  68                     o.backend_status = "OK"
  69                     o.save(update_fields=['enacted'])
  70             except Exception,e:
  71                 try:
  72                     o.backend_status = self.error_map.map(str(e))
  73                 except:
  74                     o.backend_status = str(e)
  75
  76                 o.save(update_fields=['backend_status'])
  77
  78                 logger.log_exc("sync step failed!")
  79                 failed.append(o)
  80
  81         return failed
  82
  83     def __call__(self, **args):
  84         return self.call(**args)