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):
  36
  37         self.api.auth.authenticateCred(cred, [cred, hrn], request_hash)
  38         self.api.auth.check(cred, 'resolve')
  39
  40         # load all know registry names into a prefix tree and attempt to find
  41         # the longest matching prefix
  42         good_records = []
  43         registries = Registries(self.api)
  44         hrns = registries.keys()
  45         tree = prefixTree()
  46         tree.load(hrns)
  47         registry_hrn = tree.best_match(hrn)
  48
  49         #if there was no match then this record belongs to an unknow registry
  50         if not registry_hrn:
  51             raise MissingAuthority(hrn)
  52
  53         # if the best match (longest matching hrn) is not the local registry,
  54         # forward the request
  55         if registry_hrn != self.api.hrn:
  56             credential = self.api.getCredential()
  57             credential.set_gid_origin_caller(gid_origin_caller)
  58             try:
  59                 request_hash=None
  60                 records = registries[registry_hrn].resolve(credential, hrn, request_hash)
  61                 good_records = [GeniRecord(dict=record).as_dict() for record in records]
  62             except:
  63                 arg_list = [credential, hrn]
  64                 request_hash=self.api.key.compute_hash(arg_list)
  65                 records = registries[registry_hrn].resolve(credential, hrn, request_hash)
  66                 good_records = [GeniRecord(dict=record).as_dict() for record in records]
  67
  68         if good_records:
  69             return good_records
  70
  71         # if we still havnt found the record yet, try the local registry
  72         table = GeniTable()
  73         records = table.findObjects(hrn)
  74         if not records:
  75             raise RecordNotFound(hrn)
  76         for record in records:
  77             try:
  78                 self.api.fill_record_info(record)
  79                 good_records.append(dict(record))
  80             except PlanetLabRecordDoesNotExist:
  81                 # silently drop the ones that are missing in PL
  82                 print >> log, "ignoring geni record ", record['hrn'], \
  83                               " because pl record does not exist"
  84                 table.remove(record)
  85
  86
  87         return good_records
  88