api.py

   1 import SimpleXMLRPCServer
   2 import SocketServer
   3 import cPickle
   4 import errno
   5 import os
   6 import pwd
   7 import socket
   8 import struct
   9 import threading
  10 import xmlrpclib
  11
  12 import accounts
  13 import database
  14 import logger
  15 import tools
  16
  17
  18 API_SERVER_PORT = 812
  19
  20
  21 api_method_dict = {}
  22 nargs_dict = {}
  23
  24 def export_to_api(nargs):
  25     def export(method):
  26         nargs_dict[method.__name__] = nargs
  27         api_method_dict[method.__name__] = method
  28         return method
  29     return export
  30
  31 @export_to_api(0)
  32 def DumpDatabase():
  33     """DumpDatabase(): return the entire node manager DB, pickled"""
  34     return cPickle.dumps(dict(database._db), 0)
  35
  36 @export_to_api(0)
  37 def Help():
  38     """Help(): get help"""
  39     return ''.join([method.__doc__ + '\n' for method in api_method_dict.itervalues()])
  40
  41 @export_to_api(1)
  42 def CreateSliver(rec):
  43     """CreateSliver(sliver_name): set up a non-PLC-instantiated sliver"""
  44     if not rec['plc_instantiated']:
  45         accounts.get(rec['name']).ensure_created(rec)
  46
  47 @export_to_api(1)
  48 def DeleteSliver(rec):
  49     """DeleteSliver(sliver_name): tear down a non-PLC-instantiated sliver"""
  50     if not rec['plc_instantiated']:
  51         accounts.get(rec['name']).ensure_destroyed()
  52
  53 @export_to_api(1)
  54 def Start(rec):
  55     """Start(sliver_name): run start scripts belonging to the specified sliver"""
  56     accounts.get(rec['name']).start()
  57
  58 @export_to_api(1)
  59 def Stop(rec):
  60     """Stop(sliver_name): kill all processes belonging to the specified sliver"""
  61     accounts.get(rec['name']).stop()
  62
  63 @export_to_api(1)
  64 def GetEffectiveRSpec(rec):
  65     """GetEffectiveRSpec(sliver_name): return the RSpec allocated to the specified sliver, including loans"""
  66     return tools.deepcopy(rec.get('eff_rspec', {}))
  67
  68 @export_to_api(1)
  69 def GetRSpec(rec):
  70     """GetRSpec(sliver_name): return the RSpec allocated to the specified sliver, excluding loans"""
  71     return tools.deepcopy(rec.get('rspec', {}))
  72
  73 @export_to_api(1)
  74 def GetLoans(rec):
  75     """GetLoans(sliver_name): return the list of loans made by the specified sliver"""
  76     return tools.deepcopy(rec.get('loans', []))
  77
  78 def validate_loans(obj):
  79     """Check that <obj> is a valid loan specification."""
  80     def validate_loan(obj):
  81         return (type(obj)==list or type(obj)==tuple) and len(obj)==3 and \
  82                type(obj[0])==str and \
  83                type(obj[1])==str and obj[1] in LOANABLE_RESOURCES and \
  84                type(obj[2])==int and obj[2]>0
  85     return type(obj)==list and False not in map(validate_loan, obj)
  86
  87 @export_to_api(2)
  88 def SetLoans(rec, loans):
  89     """SetLoans(sliver_name, loans): overwrite the list of loans made by the specified sliver"""
  90     if not validate_loans(loans):
  91         raise xmlrpclib.Fault(102, 'Invalid argument: the second argument must be a well-formed loan specification')
  92     rec['loans'] = loans
  93     database.deliver_records([rec])
  94
  95 api_method_list = api_method_dict.keys()
  96 api_method_list.sort()
  97
  98
  99 class APIRequestHandler(SimpleXMLRPCServer.SimpleXMLRPCRequestHandler):
 100     # overriding _dispatch to achieve this effect is officially deprecated,
 101     # but I can't figure out how to get access to .request
 102     # without duplicating SimpleXMLRPCServer code here,
 103     # which is more likely to change than the deprecated behavior
 104     # is to be broken
 105
 106     @database.synchronized
 107     def _dispatch(self, method_name, args):
 108         method_name = str(method_name)
 109         try: method = api_method_dict[method_name]
 110         except KeyError:
 111             raise xmlrpclib.Fault(100, 'Invalid API method %s.  Valid choices are %s' % (method_name, ', '.join(api_method_list)))
 112
 113         expected_nargs = nargs_dict[method_name]
 114         if len(args) != nargs_dict[method_name]:
 115             raise xmlrpclib.Fault(101, 'Invalid argument count: got %d, expecting %d.' % (len(args), expected_nargs))
 116         else:
 117             # Figure out who's calling.
 118             # XXX - these ought to be imported directly from some .h file
 119             SO_PEERCRED = 17
 120             sizeof_struct_ucred = 12
 121             ucred = self.request.getsockopt(socket.SOL_SOCKET, SO_PEERCRED,
 122                                             sizeof_struct_ucred)
 123             xid = struct.unpack('3i', ucred)[2]
 124             caller_name = pwd.getpwuid(xid)[0]
 125
 126             if expected_nargs >= 1:
 127                 target_name = args[0]
 128                 target_rec = database.get_sliver(target_name)
 129                 if not target_rec: raise xmlrpclib.Fault(102, 'Invalid argument: the first argument must be a sliver name.')
 130
 131                 if caller_name not in (args[0], 'root') and \
 132                        (caller_name, method_name) not in target_rec['delegations']:
 133                     raise xmlrpclib.Fault(108, 'Permission denied.')
 134                 result = method(target_rec, *args[1:])
 135             else:
 136                 if method_name == 'DumpDatabase' and caller_name != 'root':
 137                     raise xmlrpclib.Fault(108, 'Permission denied.')
 138                 result = method()
 139             if result == None: result = 1
 140             return result
 141
 142 class APIServer_INET(SocketServer.ThreadingMixIn,
 143                      SimpleXMLRPCServer.SimpleXMLRPCServer):
 144     allow_reuse_address = True
 145
 146 class APIServer_UNIX(APIServer_INET): address_family = socket.AF_UNIX
 147
 148 def start():
 149     """Start two XMLRPC interfaces: one bound to localhost, the other bound to a Unix domain socket."""
 150     serv1 = APIServer_INET(('127.0.0.1', API_SERVER_PORT),
 151                            requestHandler=APIRequestHandler, logRequests=0)
 152     tools.as_daemon_thread(serv1.serve_forever)
 153     unix_addr = '/tmp/node_mgr_api'
 154     try: os.unlink(unix_addr)
 155     except OSError, e:
 156         if e.errno != errno.ENOENT: raise
 157     serv2 = APIServer_UNIX(unix_addr,
 158                            requestHandler=APIRequestHandler, logRequests=0)
 159     tools.as_daemon_thread(serv2.serve_forever)
 160     os.chmod(unix_addr, 0666)