4 # Copyright (C) 2006, 2007 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 """Module for the unix socket protocol
24 This module implements the local unix socket protocl. You only need
25 this module and the opcodes module in the client program in order to
26 communicate with the master.
28 The module is also be used by the master daemon.
37 from ganeti import serializer
38 from ganeti import constants
39 from ganeti import errors
44 KEY_SUCCESS = "success"
47 REQ_SUBMIT_JOB = "SubmitJob"
48 REQ_WAIT_FOR_JOB_CHANGE = "WaitForJobChange"
49 REQ_CANCEL_JOB = "CancelJob"
50 REQ_ARCHIVE_JOB = "ArchiveJob"
51 REQ_AUTOARCHIVE_JOBS = "AutoArchiveJobs"
52 REQ_QUERY_JOBS = "QueryJobs"
53 REQ_QUERY_INSTANCES = "QueryInstances"
54 REQ_QUERY_NODES = "QueryNodes"
55 REQ_QUERY_EXPORTS = "QueryExports"
56 REQ_QUERY_CONFIG_VALUES = "QueryConfigValues"
57 REQ_QUEUE_SET_DRAIN_FLAG = "SetDrainFlag"
63 class ProtocolError(Exception):
64 """Denotes an error in the server communication"""
67 class ConnectionClosedError(ProtocolError):
68 """Connection closed error"""
71 class TimeoutError(ProtocolError):
72 """Operation timeout error"""
75 class EncodingError(ProtocolError):
76 """Encoding failure on the sending side"""
79 class DecodingError(ProtocolError):
80 """Decoding failure on the receiving side"""
83 class RequestError(ProtocolError):
86 This signifies an error in the request format or request handling,
87 but not (e.g.) an error in starting up an instance.
89 Some common conditions that can trigger this exception:
90 - job submission failed because the job data was wrong
91 - query failed because required fields were missing
96 class NoMasterError(ProtocolError):
97 """The master cannot be reached
99 This means that the master daemon is not running or the socket has
106 """Low-level transport class.
108 This is used on the client side.
110 This could be replace by any other class that provides the same
111 semantics to the Client. This means:
112 - can send messages and receive messages
113 - safe for multithreading
117 def __init__(self, address, timeouts=None, eom=None):
118 """Constructor for the Client class.
121 - address: a valid address the the used transport class
122 - timeout: a list of timeouts, to be used on connect and read/write
123 - eom: an identifier to be used as end-of-message which the
124 upper-layer will guarantee that this identifier will not appear
127 There are two timeouts used since we might want to wait for a long
128 time for a response, but the connect timeout should be lower.
130 If not passed, we use a default of 10 and respectively 60 seconds.
132 Note that on reading data, since the timeout applies to an
133 invidual receive, it might be that the total duration is longer
134 than timeout value passed (we make a hard limit at twice the read
138 self.address = address
140 self._ctimeout, self._rwtimeout = DEF_CTMO, DEF_RWTO
142 self._ctimeout, self._rwtimeout = timeouts
146 self._msgs = collections.deque()
154 self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
155 self.socket.settimeout(self._ctimeout)
157 self.socket.connect(address)
158 except socket.timeout, err:
159 raise TimeoutError("Connect timed out: %s" % str(err))
160 except socket.error, err:
161 if err.args[0] in (errno.ENOENT, errno.ECONNREFUSED):
162 raise NoMasterError((address,))
164 self.socket.settimeout(self._rwtimeout)
165 except (socket.error, NoMasterError):
166 if self.socket is not None:
171 def _CheckSocket(self):
172 """Make sure we are connected.
175 if self.socket is None:
176 raise ProtocolError("Connection is closed")
181 This just sends a message and doesn't wait for the response.
185 raise EncodingError("Message terminator found in payload")
188 self.socket.sendall(msg + self.eom)
189 except socket.timeout, err:
190 raise TimeoutError("Sending timeout: %s" % str(err))
193 """Try to receive a messae from the socket.
195 In case we already have messages queued, we just return from the
196 queue. Otherwise, we try to read data with a _rwtimeout network
197 timeout, and making sure we don't go over 2x_rwtimeout as a global
202 etime = time.time() + self._rwtimeout
203 while not self._msgs:
204 if time.time() > etime:
205 raise TimeoutError("Extended receive timeout")
207 data = self.socket.recv(4096)
208 except socket.timeout, err:
209 raise TimeoutError("Receive timeout: %s" % str(err))
211 raise ConnectionClosedError("Connection closed while reading")
212 new_msgs = (self._buffer + data).split(self.eom)
213 self._buffer = new_msgs.pop()
214 self._msgs.extend(new_msgs)
215 return self._msgs.popleft()
218 """Send a message and wait for the response.
220 This is just a wrapper over Send and Recv.
227 """Close the socket"""
228 if self.socket is not None:
233 class Client(object):
234 """High-level client implementation.
236 This uses a backing Transport-like class on top of which it
237 implements data serialization/deserialization.
240 def __init__(self, address=None, timeouts=None, transport=Transport):
241 """Constructor for the Client class.
244 - address: a valid address the the used transport class
245 - timeout: a list of timeouts, to be used on connect and read/write
246 - transport: a Transport-like class
249 If timeout is not passed, the default timeouts of the transport
254 address = constants.MASTER_SOCKET
255 self.transport = transport(address, timeouts=timeouts)
257 def CallMethod(self, method, args):
258 """Send a generic request and return the response.
267 # Send request and wait for response
268 result = self.transport.Call(serializer.DumpJson(request, indent=False))
270 data = serializer.LoadJson(result)
271 except Exception, err:
272 raise ProtocolError("Error while deserializing response: %s" % str(err))
275 if (not isinstance(data, dict) or
276 KEY_SUCCESS not in data or
277 KEY_RESULT not in data):
278 raise DecodingError("Invalid response from server: %s" % str(data))
280 result = data[KEY_RESULT]
282 if not data[KEY_SUCCESS]:
283 # TODO: decide on a standard exception
284 if (isinstance(result, (tuple, list)) and len(result) == 2 and
285 isinstance(result[1], (tuple, list))):
286 # custom ganeti errors
287 err_class = errors.GetErrorClass(result[0])
288 if err_class is not None:
289 raise err_class, tuple(result[1])
291 raise RequestError(result)
295 def SetQueueDrainFlag(self, drain_flag):
296 return self.CallMethod(REQ_QUEUE_SET_DRAIN_FLAG, drain_flag)
298 def SubmitJob(self, ops):
299 ops_state = map(lambda op: op.__getstate__(), ops)
300 return self.CallMethod(REQ_SUBMIT_JOB, ops_state)
302 def CancelJob(self, job_id):
303 return self.CallMethod(REQ_CANCEL_JOB, job_id)
305 def ArchiveJob(self, job_id):
306 return self.CallMethod(REQ_ARCHIVE_JOB, job_id)
308 def AutoArchiveJobs(self, age):
309 return self.CallMethod(REQ_AUTOARCHIVE_JOBS, age)
311 def WaitForJobChange(self, job_id, fields, prev_job_info, prev_log_serial):
312 timeout = (DEF_RWTO - 1) / 2
314 result = self.CallMethod(REQ_WAIT_FOR_JOB_CHANGE,
315 (job_id, fields, prev_job_info,
316 prev_log_serial, timeout))
317 if result != constants.JOB_NOTCHANGED:
321 def QueryJobs(self, job_ids, fields):
322 return self.CallMethod(REQ_QUERY_JOBS, (job_ids, fields))
324 def QueryInstances(self, names, fields):
325 return self.CallMethod(REQ_QUERY_INSTANCES, (names, fields))
327 def QueryNodes(self, names, fields):
328 return self.CallMethod(REQ_QUERY_NODES, (names, fields))
330 def QueryExports(self, nodes):
331 return self.CallMethod(REQ_QUERY_EXPORTS, nodes)
333 def QueryConfigValues(self, fields):
334 return self.CallMethod(REQ_QUERY_CONFIG_VALUES, fields)
337 # TODO: class Server(object)