root / lib / luxi.py @ e22af31d
History | View | Annotate | Download (11.9 kB)
1 |
#
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2006, 2007 Google Inc.
|
5 |
#
|
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.
|
10 |
#
|
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.
|
15 |
#
|
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
|
19 |
# 02110-1301, USA.
|
20 |
|
21 |
|
22 |
"""Module for the unix socket protocol
|
23 |
|
24 |
This module implements the local unix socket protocol. You only need
|
25 |
this module and the opcodes module in the client program in order to
|
26 |
communicate with the master.
|
27 |
|
28 |
The module is also used by the master daemon.
|
29 |
|
30 |
"""
|
31 |
|
32 |
import socket |
33 |
import collections |
34 |
import time |
35 |
import errno |
36 |
|
37 |
from ganeti import serializer |
38 |
from ganeti import constants |
39 |
from ganeti import errors |
40 |
from ganeti import utils |
41 |
|
42 |
|
43 |
KEY_METHOD = 'method'
|
44 |
KEY_ARGS = 'args'
|
45 |
KEY_SUCCESS = "success"
|
46 |
KEY_RESULT = "result"
|
47 |
|
48 |
REQ_SUBMIT_JOB = "SubmitJob"
|
49 |
REQ_SUBMIT_MANY_JOBS = "SubmitManyJobs"
|
50 |
REQ_WAIT_FOR_JOB_CHANGE = "WaitForJobChange"
|
51 |
REQ_CANCEL_JOB = "CancelJob"
|
52 |
REQ_ARCHIVE_JOB = "ArchiveJob"
|
53 |
REQ_AUTOARCHIVE_JOBS = "AutoArchiveJobs"
|
54 |
REQ_QUERY_JOBS = "QueryJobs"
|
55 |
REQ_QUERY_INSTANCES = "QueryInstances"
|
56 |
REQ_QUERY_NODES = "QueryNodes"
|
57 |
REQ_QUERY_EXPORTS = "QueryExports"
|
58 |
REQ_QUERY_CONFIG_VALUES = "QueryConfigValues"
|
59 |
REQ_QUERY_CLUSTER_INFO = "QueryClusterInfo"
|
60 |
REQ_QUERY_TAGS = "QueryTags"
|
61 |
REQ_QUEUE_SET_DRAIN_FLAG = "SetDrainFlag"
|
62 |
REQ_SET_WATCHER_PAUSE = "SetWatcherPause"
|
63 |
|
64 |
DEF_CTMO = 10
|
65 |
DEF_RWTO = 60
|
66 |
|
67 |
# WaitForJobChange timeout
|
68 |
WFJC_TIMEOUT = (DEF_RWTO - 1) / 2 |
69 |
|
70 |
|
71 |
class ProtocolError(Exception): |
72 |
"""Denotes an error in the server communication"""
|
73 |
|
74 |
|
75 |
class ConnectionClosedError(ProtocolError): |
76 |
"""Connection closed error"""
|
77 |
|
78 |
|
79 |
class TimeoutError(ProtocolError): |
80 |
"""Operation timeout error"""
|
81 |
|
82 |
|
83 |
class EncodingError(ProtocolError): |
84 |
"""Encoding failure on the sending side"""
|
85 |
|
86 |
|
87 |
class DecodingError(ProtocolError): |
88 |
"""Decoding failure on the receiving side"""
|
89 |
|
90 |
|
91 |
class RequestError(ProtocolError): |
92 |
"""Error on request
|
93 |
|
94 |
This signifies an error in the request format or request handling,
|
95 |
but not (e.g.) an error in starting up an instance.
|
96 |
|
97 |
Some common conditions that can trigger this exception:
|
98 |
- job submission failed because the job data was wrong
|
99 |
- query failed because required fields were missing
|
100 |
|
101 |
"""
|
102 |
|
103 |
|
104 |
class NoMasterError(ProtocolError): |
105 |
"""The master cannot be reached
|
106 |
|
107 |
This means that the master daemon is not running or the socket has
|
108 |
been removed.
|
109 |
|
110 |
"""
|
111 |
|
112 |
|
113 |
class Transport: |
114 |
"""Low-level transport class.
|
115 |
|
116 |
This is used on the client side.
|
117 |
|
118 |
This could be replace by any other class that provides the same
|
119 |
semantics to the Client. This means:
|
120 |
- can send messages and receive messages
|
121 |
- safe for multithreading
|
122 |
|
123 |
"""
|
124 |
|
125 |
def __init__(self, address, timeouts=None): |
126 |
"""Constructor for the Client class.
|
127 |
|
128 |
Arguments:
|
129 |
- address: a valid address the the used transport class
|
130 |
- timeout: a list of timeouts, to be used on connect and read/write
|
131 |
|
132 |
There are two timeouts used since we might want to wait for a long
|
133 |
time for a response, but the connect timeout should be lower.
|
134 |
|
135 |
If not passed, we use a default of 10 and respectively 60 seconds.
|
136 |
|
137 |
Note that on reading data, since the timeout applies to an
|
138 |
invidual receive, it might be that the total duration is longer
|
139 |
than timeout value passed (we make a hard limit at twice the read
|
140 |
timeout).
|
141 |
|
142 |
"""
|
143 |
self.address = address
|
144 |
if timeouts is None: |
145 |
self._ctimeout, self._rwtimeout = DEF_CTMO, DEF_RWTO |
146 |
else:
|
147 |
self._ctimeout, self._rwtimeout = timeouts |
148 |
|
149 |
self.socket = None |
150 |
self._buffer = "" |
151 |
self._msgs = collections.deque()
|
152 |
|
153 |
try:
|
154 |
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
|
155 |
|
156 |
# Try to connect
|
157 |
try:
|
158 |
utils.Retry(self._Connect, 1.0, self._ctimeout, |
159 |
args=(self.socket, address, self._ctimeout)) |
160 |
except utils.RetryTimeout:
|
161 |
raise TimeoutError("Connect timed out") |
162 |
|
163 |
self.socket.settimeout(self._rwtimeout) |
164 |
except (socket.error, NoMasterError):
|
165 |
if self.socket is not None: |
166 |
self.socket.close()
|
167 |
self.socket = None |
168 |
raise
|
169 |
|
170 |
@staticmethod
|
171 |
def _Connect(sock, address, timeout): |
172 |
sock.settimeout(timeout) |
173 |
try:
|
174 |
sock.connect(address) |
175 |
except socket.timeout, err:
|
176 |
raise TimeoutError("Connect timed out: %s" % str(err)) |
177 |
except socket.error, err:
|
178 |
if err.args[0] in (errno.ENOENT, errno.ECONNREFUSED): |
179 |
raise NoMasterError(address)
|
180 |
if err.args[0] == errno.EAGAIN: |
181 |
# Server's socket backlog is full at the moment
|
182 |
raise utils.RetryAgain()
|
183 |
raise
|
184 |
|
185 |
def _CheckSocket(self): |
186 |
"""Make sure we are connected.
|
187 |
|
188 |
"""
|
189 |
if self.socket is None: |
190 |
raise ProtocolError("Connection is closed") |
191 |
|
192 |
def Send(self, msg): |
193 |
"""Send a message.
|
194 |
|
195 |
This just sends a message and doesn't wait for the response.
|
196 |
|
197 |
"""
|
198 |
if constants.LUXI_EOM in msg: |
199 |
raise EncodingError("Message terminator found in payload") |
200 |
self._CheckSocket()
|
201 |
try:
|
202 |
# TODO: sendall is not guaranteed to send everything
|
203 |
self.socket.sendall(msg + constants.LUXI_EOM)
|
204 |
except socket.timeout, err:
|
205 |
raise TimeoutError("Sending timeout: %s" % str(err)) |
206 |
|
207 |
def Recv(self): |
208 |
"""Try to receive a message from the socket.
|
209 |
|
210 |
In case we already have messages queued, we just return from the
|
211 |
queue. Otherwise, we try to read data with a _rwtimeout network
|
212 |
timeout, and making sure we don't go over 2x_rwtimeout as a global
|
213 |
limit.
|
214 |
|
215 |
"""
|
216 |
self._CheckSocket()
|
217 |
etime = time.time() + self._rwtimeout
|
218 |
while not self._msgs: |
219 |
if time.time() > etime:
|
220 |
raise TimeoutError("Extended receive timeout") |
221 |
while True: |
222 |
try:
|
223 |
data = self.socket.recv(4096) |
224 |
except socket.error, err:
|
225 |
if err.args and err.args[0] == errno.EAGAIN: |
226 |
continue
|
227 |
raise
|
228 |
except socket.timeout, err:
|
229 |
raise TimeoutError("Receive timeout: %s" % str(err)) |
230 |
break
|
231 |
if not data: |
232 |
raise ConnectionClosedError("Connection closed while reading") |
233 |
new_msgs = (self._buffer + data).split(constants.LUXI_EOM)
|
234 |
self._buffer = new_msgs.pop()
|
235 |
self._msgs.extend(new_msgs)
|
236 |
return self._msgs.popleft() |
237 |
|
238 |
def Call(self, msg): |
239 |
"""Send a message and wait for the response.
|
240 |
|
241 |
This is just a wrapper over Send and Recv.
|
242 |
|
243 |
"""
|
244 |
self.Send(msg)
|
245 |
return self.Recv() |
246 |
|
247 |
def Close(self): |
248 |
"""Close the socket"""
|
249 |
if self.socket is not None: |
250 |
self.socket.close()
|
251 |
self.socket = None |
252 |
|
253 |
|
254 |
class Client(object): |
255 |
"""High-level client implementation.
|
256 |
|
257 |
This uses a backing Transport-like class on top of which it
|
258 |
implements data serialization/deserialization.
|
259 |
|
260 |
"""
|
261 |
def __init__(self, address=None, timeouts=None, transport=Transport): |
262 |
"""Constructor for the Client class.
|
263 |
|
264 |
Arguments:
|
265 |
- address: a valid address the the used transport class
|
266 |
- timeout: a list of timeouts, to be used on connect and read/write
|
267 |
- transport: a Transport-like class
|
268 |
|
269 |
|
270 |
If timeout is not passed, the default timeouts of the transport
|
271 |
class are used.
|
272 |
|
273 |
"""
|
274 |
if address is None: |
275 |
address = constants.MASTER_SOCKET |
276 |
self.address = address
|
277 |
self.timeouts = timeouts
|
278 |
self.transport_class = transport
|
279 |
self.transport = None |
280 |
self._InitTransport()
|
281 |
|
282 |
def _InitTransport(self): |
283 |
"""(Re)initialize the transport if needed.
|
284 |
|
285 |
"""
|
286 |
if self.transport is None: |
287 |
self.transport = self.transport_class(self.address, |
288 |
timeouts=self.timeouts)
|
289 |
|
290 |
def _CloseTransport(self): |
291 |
"""Close the transport, ignoring errors.
|
292 |
|
293 |
"""
|
294 |
if self.transport is None: |
295 |
return
|
296 |
try:
|
297 |
old_transp = self.transport
|
298 |
self.transport = None |
299 |
old_transp.Close() |
300 |
except Exception: # pylint: disable-msg=W0703 |
301 |
pass
|
302 |
|
303 |
def CallMethod(self, method, args): |
304 |
"""Send a generic request and return the response.
|
305 |
|
306 |
"""
|
307 |
# Build request
|
308 |
request = { |
309 |
KEY_METHOD: method, |
310 |
KEY_ARGS: args, |
311 |
} |
312 |
|
313 |
# Serialize the request
|
314 |
send_data = serializer.DumpJson(request, indent=False)
|
315 |
|
316 |
# Send request and wait for response
|
317 |
try:
|
318 |
self._InitTransport()
|
319 |
result = self.transport.Call(send_data)
|
320 |
except Exception: |
321 |
self._CloseTransport()
|
322 |
raise
|
323 |
|
324 |
# Parse the result
|
325 |
try:
|
326 |
data = serializer.LoadJson(result) |
327 |
except Exception, err: |
328 |
raise ProtocolError("Error while deserializing response: %s" % str(err)) |
329 |
|
330 |
# Validate response
|
331 |
if (not isinstance(data, dict) or |
332 |
KEY_SUCCESS not in data or |
333 |
KEY_RESULT not in data): |
334 |
raise DecodingError("Invalid response from server: %s" % str(data)) |
335 |
|
336 |
result = data[KEY_RESULT] |
337 |
|
338 |
if not data[KEY_SUCCESS]: |
339 |
errors.MaybeRaise(result) |
340 |
raise RequestError(result)
|
341 |
|
342 |
return result
|
343 |
|
344 |
def SetQueueDrainFlag(self, drain_flag): |
345 |
return self.CallMethod(REQ_QUEUE_SET_DRAIN_FLAG, drain_flag) |
346 |
|
347 |
def SetWatcherPause(self, until): |
348 |
return self.CallMethod(REQ_SET_WATCHER_PAUSE, [until]) |
349 |
|
350 |
def SubmitJob(self, ops): |
351 |
ops_state = map(lambda op: op.__getstate__(), ops) |
352 |
return self.CallMethod(REQ_SUBMIT_JOB, ops_state) |
353 |
|
354 |
def SubmitManyJobs(self, jobs): |
355 |
jobs_state = [] |
356 |
for ops in jobs: |
357 |
jobs_state.append([op.__getstate__() for op in ops]) |
358 |
return self.CallMethod(REQ_SUBMIT_MANY_JOBS, jobs_state) |
359 |
|
360 |
def CancelJob(self, job_id): |
361 |
return self.CallMethod(REQ_CANCEL_JOB, job_id) |
362 |
|
363 |
def ArchiveJob(self, job_id): |
364 |
return self.CallMethod(REQ_ARCHIVE_JOB, job_id) |
365 |
|
366 |
def AutoArchiveJobs(self, age): |
367 |
timeout = (DEF_RWTO - 1) / 2 |
368 |
return self.CallMethod(REQ_AUTOARCHIVE_JOBS, (age, timeout)) |
369 |
|
370 |
def WaitForJobChangeOnce(self, job_id, fields, |
371 |
prev_job_info, prev_log_serial, |
372 |
timeout=WFJC_TIMEOUT): |
373 |
"""Waits for changes on a job.
|
374 |
|
375 |
@param job_id: Job ID
|
376 |
@type fields: list
|
377 |
@param fields: List of field names to be observed
|
378 |
@type prev_job_info: None or list
|
379 |
@param prev_job_info: Previously received job information
|
380 |
@type prev_log_serial: None or int/long
|
381 |
@param prev_log_serial: Highest log serial number previously received
|
382 |
@type timeout: int/float
|
383 |
@param timeout: Timeout in seconds (values larger than L{WFJC_TIMEOUT} will
|
384 |
be capped to that value)
|
385 |
|
386 |
"""
|
387 |
assert timeout >= 0, "Timeout can not be negative" |
388 |
return self.CallMethod(REQ_WAIT_FOR_JOB_CHANGE, |
389 |
(job_id, fields, prev_job_info, |
390 |
prev_log_serial, |
391 |
min(WFJC_TIMEOUT, timeout)))
|
392 |
|
393 |
def WaitForJobChange(self, job_id, fields, prev_job_info, prev_log_serial): |
394 |
while True: |
395 |
result = self.WaitForJobChangeOnce(job_id, fields,
|
396 |
prev_job_info, prev_log_serial) |
397 |
if result != constants.JOB_NOTCHANGED:
|
398 |
break
|
399 |
return result
|
400 |
|
401 |
def QueryJobs(self, job_ids, fields): |
402 |
return self.CallMethod(REQ_QUERY_JOBS, (job_ids, fields)) |
403 |
|
404 |
def QueryInstances(self, names, fields, use_locking): |
405 |
return self.CallMethod(REQ_QUERY_INSTANCES, (names, fields, use_locking)) |
406 |
|
407 |
def QueryNodes(self, names, fields, use_locking): |
408 |
return self.CallMethod(REQ_QUERY_NODES, (names, fields, use_locking)) |
409 |
|
410 |
def QueryExports(self, nodes, use_locking): |
411 |
return self.CallMethod(REQ_QUERY_EXPORTS, (nodes, use_locking)) |
412 |
|
413 |
def QueryClusterInfo(self): |
414 |
return self.CallMethod(REQ_QUERY_CLUSTER_INFO, ()) |
415 |
|
416 |
def QueryConfigValues(self, fields): |
417 |
return self.CallMethod(REQ_QUERY_CONFIG_VALUES, fields) |
418 |
|
419 |
def QueryTags(self, kind, name): |
420 |
return self.CallMethod(REQ_QUERY_TAGS, (kind, name)) |