sfa/methods/resolve.py

   1 ### $Id$
   2 ### $URL$
   3 import traceback
   4 from sfa.util.faults import *
   5 from sfa.util.method import Method
   6 from sfa.util.parameter import Parameter, Mixed
   7 from sfa.trust.auth import Auth
   8 from sfa.util.record import GeniRecord
   9 from sfa.util.debug import log
  10 from sfa.server.registry import Registries
  11 from sfa.util.prefixTree import prefixTree
  12
  13 class resolve(Method):
  14     """
  15     Resolve a record.
  16
  17     @param cred credential string authorizing the caller
  18     @param hrn human readable name to resolve
  19     @return a list of record dictionaries or empty list
  20     """
  21
  22     interfaces = ['registry']
  23
  24     accepts = [
  25         Parameter(str, "Credential string"),
  26         Parameter(str, "Human readable name (hrn)")
  27         ]
  28
  29     returns = [GeniRecord]
  30
  31     def call(self, cred, hrn):
  32
  33         self.api.auth.check(cred, 'resolve')
  34         good_records = []
  35
  36         # load all know registry names into a prefix tree and attempt to find
  37         # the longest matching prefix
  38         registries = Registries(self.api)
  39         hrns = registries.keys()
  40         tree = prefixTree()
  41         tree.load(hrns)
  42         registry_hrn = tree.best_match(hrn)
  43
  44         #if there was no match then this record belongs to an unknow registry
  45         if not registry_hrn:
  46             raise MissingAuthority(hrn)
  47
  48         # if the best match (longest matching hrn) is not the local registry,
  49         # forward the request
  50         if registry_hrn != self.api.hrn:
  51             credential = self.api.getCredential()
  52             try:
  53                 records = registries[registry_hrn].resolve(credential, hrn)
  54                 good_records = [record.as_dict() for record in records]
  55                 if good_records:
  56                     return good_records
  57             except:
  58                 traceback.print_exc()
  59
  60         # if we still havnt found the record yet, try the local registry
  61         auth_hrn = self.api.auth.get_authority(hrn)
  62         if not auth_hrn:
  63             auth_hrn = hrn
  64         table = self.api.auth.get_auth_table(auth_hrn)
  65         records = table.resolve('*', hrn)
  66         if not records:
  67             raise RecordNotFound(hrn)
  68         for record in records:
  69             try:
  70                 self.api.fill_record_info(record)
  71                 good_records.append(dict(record))
  72             except PlanetLabRecordDoesNotExist:
  73                 # silently drop the ones that are missing in PL
  74                 print >> log, "ignoring geni record ", record.get_name(), \
  75                               " because pl record does not exist"
  76                 table.remove(record)
  77
  78
  79         return good_records
  80