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