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, caller_cred=None):
  36
  37         self.api.auth.authenticateCred(cred, [cred, hrn], request_hash)
  38         self.api.auth.check(cred, 'resolve')
  39         if caller_cred==None:
  40             caller_cred=cred
  41
  42         #log the call
  43         self.api.logger.info("interface: %s\tcaller-hrn: %s\ttarget-hrn: %s\tmethod-name: %s"%(self.api.interface, Credential(string=caller_cred).get_gid_caller().get_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                 records = registries[registry_hrn].resolve(credential, hrn, caller_cred=caller_cred)
  64                 good_records = [record.as_dict() for record in records]
  65                 if good_records:
  66                     return good_records
  67             except:
  68                 traceback.print_exc()
  69
  70         # if we still havnt found the record yet, try the local registry
  71         table = GeniTable()
  72         records = table.findObjects(hrn)
  73         if not records:
  74             raise RecordNotFound(hrn)
  75         for record in records:
  76             try:
  77                 self.api.fill_record_info(record)
  78                 good_records.append(dict(record))
  79             except PlanetLabRecordDoesNotExist:
  80                 # silently drop the ones that are missing in PL
  81                 print >> log, "ignoring geni record ", record['hrn'], \
  82                               " because pl record does not exist"
  83                 table.remove(record)
  84
  85
  86         return good_records
  87