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.genitable import GeniTable
  10 from sfa.util.debug import log
  11 from sfa.server.registry import Registries
  12 from sfa.util.prefixTree import prefixTree
  13 from sfa.trust.credential import Credential
  14
  15 class resolve(Method):
  16     """
  17     Resolve a record.
  18
  19     @param cred credential string authorizing the caller
  20     @param hrn human readable name to resolve
  21     @return a list of record dictionaries or empty list
  22     """
  23
  24     interfaces = ['registry']
  25
  26     accepts = [
  27         Parameter(str, "Credential string"),
  28         Parameter(str, "Human readable name (hrn)"),
  29         Mixed(Parameter(str, "Request hash"),
  30               Parameter(None, "Request hash not specified"))
  31         ]
  32
  33     returns = [GeniRecord]
  34
  35     def call(self, cred, hrn, request_hash=None, origin_hrn=None):
  36
  37         self.api.auth.authenticateCred(cred, [cred, hrn], request_hash)
  38         self.api.auth.check(cred, 'resolve')
  39         if origin_hrn==None:
  40             origin_hrn=Credential(string=cred).get_gid_caller().get_hrn()
  41
  42         #log the call
  43         self.api.logger.info("interface: %s\tcaller-hrn: %s\ttarget-hrn: %s\tmethod-name: %s"%(self.api.interface, origin_hrn, hrn, self.name))
  44         good_records = []
  45
  46         # load all know registry names into a prefix tree and attempt to find
  47         # the longest matching prefix
  48         registries = Registries(self.api)
  49         hrns = registries.keys()
  50         tree = prefixTree()
  51         tree.load(hrns)
  52         registry_hrn = tree.best_match(hrn)
  53
  54         #if there was no match then this record belongs to an unknow registry
  55         if not registry_hrn:
  56             raise MissingAuthority(hrn)
  57
  58         # if the best match (longest matching hrn) is not the local registry,
  59         # forward the request
  60         if registry_hrn != self.api.hrn:
  61             credential = self.api.getCredential()
  62             try:
  63                 request_hash=None
  64                 records = registries[registry_hrn].resolve(credential, hrn, request_hash, origin_hrn)
  65                 good_records = [GeniRecord(dict=record).as_dict() for record in records]
  66             except:
  67                 arg_list = [credential, hrn]
  68                 request_hash=self.api.key.compute_hash(arg_list)
  69                 records = registries[registry_hrn].resolve(credential, hrn, request_hash, origin_hrn)
  70                 good_records = [GeniRecord(dict=record).as_dict() for record in records]
  71
  72         if good_records:
  73             return good_records
  74
  75         # if we still havnt found the record yet, try the local registry
  76         table = GeniTable()
  77         records = table.findObjects(hrn)
  78         if not records:
  79             raise RecordNotFound(hrn)
  80         for record in records:
  81             try:
  82                 self.api.fill_record_info(record)
  83                 good_records.append(dict(record))
  84             except PlanetLabRecordDoesNotExist:
  85                 # silently drop the ones that are missing in PL
  86                 print >> log, "ignoring geni record ", record['hrn'], \
  87                               " because pl record does not exist"
  88                 table.remove(record)
  89
  90
  91         return good_records
  92