root / lib / luxi.py @ 04864530
History | View | Annotate | Download (8.1 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 protocl. 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 be used by the master daemon.
|
29 |
|
30 |
"""
|
31 |
|
32 |
import socket |
33 |
import collections |
34 |
import simplejson |
35 |
import time |
36 |
import errno |
37 |
|
38 |
from ganeti import opcodes |
39 |
from ganeti import constants |
40 |
|
41 |
|
42 |
KEY_REQUEST = 'request'
|
43 |
KEY_DATA = 'data'
|
44 |
REQ_SUBMIT = 'submit'
|
45 |
REQ_ABORT = 'abort'
|
46 |
REQ_QUERY = 'query'
|
47 |
|
48 |
DEF_CTMO = 10
|
49 |
DEF_RWTO = 60
|
50 |
|
51 |
|
52 |
class ProtocolError(Exception): |
53 |
"""Denotes an error in the server communication"""
|
54 |
|
55 |
|
56 |
class ConnectionClosedError(ProtocolError): |
57 |
"""Connection closed error"""
|
58 |
|
59 |
|
60 |
class TimeoutError(ProtocolError): |
61 |
"""Operation timeout error"""
|
62 |
|
63 |
|
64 |
class EncodingError(ProtocolError): |
65 |
"""Encoding failure on the sending side"""
|
66 |
|
67 |
|
68 |
class DecodingError(ProtocolError): |
69 |
"""Decoding failure on the receiving side"""
|
70 |
|
71 |
|
72 |
class RequestError(ProtocolError): |
73 |
"""Error on request
|
74 |
|
75 |
This signifies an error in the request format or request handling,
|
76 |
but not (e.g.) an error in starting up an instance.
|
77 |
|
78 |
Some common conditions that can trigger this exception:
|
79 |
- job submission failed because the job data was wrong
|
80 |
- query failed because required fields were missing
|
81 |
|
82 |
"""
|
83 |
|
84 |
class NoMasterError(ProtocolError): |
85 |
"""The master cannot be reached
|
86 |
|
87 |
This means that the master daemon is not running or the socket has
|
88 |
been removed.
|
89 |
|
90 |
"""
|
91 |
|
92 |
|
93 |
def SerializeJob(job): |
94 |
"""Convert a job description to a string format.
|
95 |
|
96 |
"""
|
97 |
return simplejson.dumps(job.__getstate__())
|
98 |
|
99 |
|
100 |
def UnserializeJob(data): |
101 |
"""Load a job from a string format"""
|
102 |
try:
|
103 |
new_data = simplejson.loads(data) |
104 |
except Exception, err: |
105 |
raise DecodingError("Error while unserializing: %s" % str(err)) |
106 |
job = opcodes.Job() |
107 |
job.__setstate__(new_data) |
108 |
return job
|
109 |
|
110 |
|
111 |
class Transport: |
112 |
"""Low-level transport class.
|
113 |
|
114 |
This is used on the client side.
|
115 |
|
116 |
This could be replace by any other class that provides the same
|
117 |
semantics to the Client. This means:
|
118 |
- can send messages and receive messages
|
119 |
- safe for multithreading
|
120 |
|
121 |
"""
|
122 |
|
123 |
def __init__(self, address, timeouts=None, eom=None): |
124 |
"""Constructor for the Client class.
|
125 |
|
126 |
Arguments:
|
127 |
- address: a valid address the the used transport class
|
128 |
- timeout: a list of timeouts, to be used on connect and read/write
|
129 |
- eom: an identifier to be used as end-of-message which the
|
130 |
upper-layer will guarantee that this identifier will not appear
|
131 |
in any message
|
132 |
|
133 |
There are two timeouts used since we might want to wait for a long
|
134 |
time for a response, but the connect timeout should be lower.
|
135 |
|
136 |
If not passed, we use a default of 10 and respectively 60 seconds.
|
137 |
|
138 |
Note that on reading data, since the timeout applies to an
|
139 |
invidual receive, it might be that the total duration is longer
|
140 |
than timeout value passed (we make a hard limit at twice the read
|
141 |
timeout).
|
142 |
|
143 |
"""
|
144 |
self.address = address
|
145 |
if timeouts is None: |
146 |
self._ctimeout, self._rwtimeout = DEF_CTMO, DEF_RWTO |
147 |
else:
|
148 |
self._ctimeout, self._rwtimeout = timeouts |
149 |
|
150 |
self.socket = None |
151 |
self._buffer = "" |
152 |
self._msgs = collections.deque()
|
153 |
|
154 |
if eom is None: |
155 |
self.eom = '\3' |
156 |
else:
|
157 |
self.eom = eom
|
158 |
|
159 |
try:
|
160 |
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
|
161 |
self.socket.settimeout(self._ctimeout) |
162 |
try:
|
163 |
self.socket.connect(address)
|
164 |
except socket.timeout, err:
|
165 |
raise TimeoutError("Connect timed out: %s" % str(err)) |
166 |
except socket.error, err:
|
167 |
if err.args[0] == errno.ENOENT: |
168 |
raise NoMasterError((address,))
|
169 |
raise
|
170 |
self.socket.settimeout(self._rwtimeout) |
171 |
except (socket.error, NoMasterError):
|
172 |
if self.socket is not None: |
173 |
self.socket.close()
|
174 |
self.socket = None |
175 |
raise
|
176 |
|
177 |
def _CheckSocket(self): |
178 |
"""Make sure we are connected.
|
179 |
|
180 |
"""
|
181 |
if self.socket is None: |
182 |
raise ProtocolError("Connection is closed") |
183 |
|
184 |
def Send(self, msg): |
185 |
"""Send a message.
|
186 |
|
187 |
This just sends a message and doesn't wait for the response.
|
188 |
|
189 |
"""
|
190 |
if self.eom in msg: |
191 |
raise EncodingError("Message terminator found in payload") |
192 |
self._CheckSocket()
|
193 |
try:
|
194 |
self.socket.sendall(msg + self.eom) |
195 |
except socket.timeout, err:
|
196 |
raise TimeoutError("Sending timeout: %s" % str(err)) |
197 |
|
198 |
def Recv(self): |
199 |
"""Try to receive a messae from the socket.
|
200 |
|
201 |
In case we already have messages queued, we just return from the
|
202 |
queue. Otherwise, we try to read data with a _rwtimeout network
|
203 |
timeout, and making sure we don't go over 2x_rwtimeout as a global
|
204 |
limit.
|
205 |
|
206 |
"""
|
207 |
self._CheckSocket()
|
208 |
etime = time.time() + self._rwtimeout
|
209 |
while not self._msgs: |
210 |
if time.time() > etime:
|
211 |
raise TimeoutError("Extended receive timeout") |
212 |
try:
|
213 |
data = self.socket.recv(4096) |
214 |
except socket.timeout, err:
|
215 |
raise TimeoutError("Receive timeout: %s" % str(err)) |
216 |
if not data: |
217 |
raise ConnectionClosedError("Connection closed while reading") |
218 |
new_msgs = (self._buffer + data).split(self.eom) |
219 |
self._buffer = new_msgs.pop()
|
220 |
self._msgs.extend(new_msgs)
|
221 |
return self._msgs.popleft() |
222 |
|
223 |
def Call(self, msg): |
224 |
"""Send a message and wait for the response.
|
225 |
|
226 |
This is just a wrapper over Send and Recv.
|
227 |
|
228 |
"""
|
229 |
self.Send(msg)
|
230 |
return self.Recv() |
231 |
|
232 |
def Close(self): |
233 |
"""Close the socket"""
|
234 |
if self.socket is not None: |
235 |
self.socket.close()
|
236 |
self.socket = None |
237 |
|
238 |
|
239 |
class Client(object): |
240 |
"""High-level client implementation.
|
241 |
|
242 |
This uses a backing Transport-like class on top of which it
|
243 |
implements data serialization/deserialization.
|
244 |
|
245 |
"""
|
246 |
def __init__(self, address=None, timeouts=None, transport=Transport): |
247 |
"""Constructor for the Client class.
|
248 |
|
249 |
Arguments:
|
250 |
- address: a valid address the the used transport class
|
251 |
- timeout: a list of timeouts, to be used on connect and read/write
|
252 |
- transport: a Transport-like class
|
253 |
|
254 |
|
255 |
If timeout is not passed, the default timeouts of the transport
|
256 |
class are used.
|
257 |
|
258 |
"""
|
259 |
if address is None: |
260 |
address = constants.MASTER_SOCKET |
261 |
self.transport = transport(address, timeouts=timeouts)
|
262 |
|
263 |
def SendRequest(self, request, data): |
264 |
"""Send a generic request and return the response.
|
265 |
|
266 |
"""
|
267 |
msg = {KEY_REQUEST: request, KEY_DATA: data} |
268 |
result = self.transport.Call(simplejson.dumps(msg))
|
269 |
try:
|
270 |
data = simplejson.loads(result) |
271 |
except Exception, err: |
272 |
raise ProtocolError("Error while deserializing response: %s" % str(err)) |
273 |
if (not isinstance(data, dict) or |
274 |
'success' not in data or |
275 |
'result' not in data): |
276 |
raise DecodingError("Invalid response from server: %s" % str(data)) |
277 |
return data
|
278 |
|
279 |
def SubmitJob(self, job): |
280 |
"""Submit a job"""
|
281 |
result = self.SendRequest(REQ_SUBMIT, SerializeJob(job))
|
282 |
if not result['success']: |
283 |
raise RequestError(result['result']) |
284 |
return result['result'] |
285 |
|
286 |
def Query(self, data): |
287 |
"""Make a query"""
|
288 |
result = self.SendRequest(REQ_QUERY, data)
|
289 |
if not result['success']: |
290 |
raise RequestError(result[result])
|
291 |
result = result['result']
|
292 |
if data["object"] == "jobs": |
293 |
# custom job processing of query values
|
294 |
for row in result: |
295 |
for idx, field in enumerate(data["fields"]): |
296 |
if field == "op_list": |
297 |
row[idx] = [opcodes.OpCode.LoadOpCode(i) for i in row[idx]] |
298 |
return result
|