root / lib / hypervisor / hv_chroot.py @ 9b94905f
History | View | Annotate | Download (8.4 kB)
1 |
#
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2006, 2007, 2008, 2009 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 |
"""Chroot manager hypervisor
|
23 |
|
24 |
"""
|
25 |
|
26 |
import os |
27 |
import os.path |
28 |
import time |
29 |
import logging |
30 |
from cStringIO import StringIO |
31 |
|
32 |
from ganeti import constants |
33 |
from ganeti import errors |
34 |
from ganeti import utils |
35 |
from ganeti.hypervisor import hv_base |
36 |
from ganeti.errors import HypervisorError |
37 |
|
38 |
|
39 |
class ChrootManager(hv_base.BaseHypervisor): |
40 |
"""Chroot manager.
|
41 |
|
42 |
This not-really hypervisor allows ganeti to manage chroots. It has
|
43 |
special behaviour and requirements on the OS definition and the node
|
44 |
environemnt:
|
45 |
- the start and stop of the chroot environment are done via a
|
46 |
script called ganeti-chroot located in the root directory of the
|
47 |
first drive, which should be created by the OS definition
|
48 |
- this script must accept the start and stop argument and, on
|
49 |
shutdown, it should cleanly shutdown the daemons/processes
|
50 |
using the chroot
|
51 |
- the daemons run in chroot should only bind to the instance IP
|
52 |
(to which the OS create script has access via the instance name)
|
53 |
- since some daemons in the node could be listening on the wildcard
|
54 |
address, some ports might be unavailable
|
55 |
- the instance listing will show no memory usage
|
56 |
- on shutdown, the chroot manager will try to find all mountpoints
|
57 |
under the root dir of the instance and unmount them
|
58 |
- instance alive check is based on whether any process is using the chroot
|
59 |
|
60 |
"""
|
61 |
_ROOT_DIR = constants.RUN_GANETI_DIR + "/chroot-hypervisor"
|
62 |
|
63 |
PARAMETERS = { |
64 |
constants.HV_INIT_SCRIPT: (True, utils.IsNormAbsPath,
|
65 |
"must be an absolute normalized path",
|
66 |
None, None), |
67 |
} |
68 |
|
69 |
def __init__(self): |
70 |
hv_base.BaseHypervisor.__init__(self)
|
71 |
if not os.path.exists(self._ROOT_DIR): |
72 |
os.mkdir(self._ROOT_DIR)
|
73 |
if not os.path.isdir(self._ROOT_DIR): |
74 |
raise HypervisorError("Needed path %s is not a directory" % |
75 |
self._ROOT_DIR)
|
76 |
|
77 |
@staticmethod
|
78 |
def _IsDirLive(path): |
79 |
"""Check if a directory looks like a live chroot.
|
80 |
|
81 |
"""
|
82 |
if not os.path.ismount(path): |
83 |
return False |
84 |
result = utils.RunCmd(["fuser", "-m", path]) |
85 |
return not result.failed |
86 |
|
87 |
@staticmethod
|
88 |
def _GetMountSubdirs(path): |
89 |
"""Return the list of mountpoints under a given path.
|
90 |
|
91 |
This function is Linux-specific.
|
92 |
|
93 |
"""
|
94 |
#TODO(iustin): investigate and document non-linux options
|
95 |
#(e.g. via mount output)
|
96 |
data = [] |
97 |
fh = open("/proc/mounts", "r") |
98 |
try:
|
99 |
for line in fh: |
100 |
fstype, mountpoint, rest = line.split(" ", 2) |
101 |
if (mountpoint.startswith(path) and |
102 |
mountpoint != path): |
103 |
data.append(mountpoint) |
104 |
finally:
|
105 |
fh.close() |
106 |
data.sort(key=lambda x: x.count("/"), reverse=True) |
107 |
return data
|
108 |
|
109 |
def ListInstances(self): |
110 |
"""Get the list of running instances.
|
111 |
|
112 |
"""
|
113 |
return [name for name in os.listdir(self._ROOT_DIR) |
114 |
if self._IsDirLive(os.path.join(self._ROOT_DIR, name))] |
115 |
|
116 |
def GetInstanceInfo(self, instance_name): |
117 |
"""Get instance properties.
|
118 |
|
119 |
@type instance_name: string
|
120 |
@param instance_name: the instance name
|
121 |
|
122 |
@return: (name, id, memory, vcpus, stat, times)
|
123 |
|
124 |
"""
|
125 |
dir_name = "%s/%s" % (self._ROOT_DIR, instance_name) |
126 |
if not self._IsDirLive(dir_name): |
127 |
raise HypervisorError("Instance %s is not running" % instance_name) |
128 |
return (instance_name, 0, 0, 0, 0, 0) |
129 |
|
130 |
def GetAllInstancesInfo(self): |
131 |
"""Get properties of all instances.
|
132 |
|
133 |
@return: [(name, id, memory, vcpus, stat, times),...]
|
134 |
|
135 |
"""
|
136 |
data = [] |
137 |
for file_name in os.listdir(self._ROOT_DIR): |
138 |
path = os.path.join(self._ROOT_DIR, file_name)
|
139 |
if self._IsDirLive(path): |
140 |
data.append((file_name, 0, 0, 0, 0, 0)) |
141 |
return data
|
142 |
|
143 |
def StartInstance(self, instance, block_devices): |
144 |
"""Start an instance.
|
145 |
|
146 |
For the chroot manager, we try to mount the block device and
|
147 |
execute '/ganeti-chroot start'.
|
148 |
|
149 |
"""
|
150 |
root_dir = "%s/%s" % (self._ROOT_DIR, instance.name) |
151 |
if not os.path.exists(root_dir): |
152 |
try:
|
153 |
os.mkdir(root_dir) |
154 |
except IOError, err: |
155 |
raise HypervisorError("Failed to start instance %s: %s" % |
156 |
(instance.name, err)) |
157 |
if not os.path.isdir(root_dir): |
158 |
raise HypervisorError("Needed path %s is not a directory" % root_dir) |
159 |
|
160 |
if not os.path.ismount(root_dir): |
161 |
if not block_devices: |
162 |
raise HypervisorError("The chroot manager needs at least one disk") |
163 |
|
164 |
sda_dev_path = block_devices[0][1] |
165 |
result = utils.RunCmd(["mount", sda_dev_path, root_dir])
|
166 |
if result.failed:
|
167 |
raise HypervisorError("Can't mount the chroot dir: %s" % result.output) |
168 |
init_script = instance.hvparams[constants.HV_INIT_SCRIPT] |
169 |
result = utils.RunCmd(["chroot", root_dir, init_script, "start"]) |
170 |
if result.failed:
|
171 |
raise HypervisorError("Can't run the chroot start script: %s" % |
172 |
result.output) |
173 |
|
174 |
def StopInstance(self, instance, force=False, retry=False): |
175 |
"""Stop an instance.
|
176 |
|
177 |
This method has complicated cleanup tests, as we must:
|
178 |
- try to kill all leftover processes
|
179 |
- try to unmount any additional sub-mountpoints
|
180 |
- finally unmount the instance dir
|
181 |
|
182 |
"""
|
183 |
root_dir = "%s/%s" % (self._ROOT_DIR, instance.name) |
184 |
if not os.path.exists(root_dir) or not self._IsDirLive(root_dir): |
185 |
return
|
186 |
|
187 |
# Run the chroot stop script only once
|
188 |
if not retry and not force: |
189 |
result = utils.RunCmd(["chroot", root_dir, "/ganeti-chroot", "stop"]) |
190 |
if result.failed:
|
191 |
raise HypervisorError("Can't run the chroot stop script: %s" % |
192 |
result.output) |
193 |
|
194 |
if not force: |
195 |
utils.RunCmd(["fuser", "-k", "-TERM", "-m", root_dir]) |
196 |
else:
|
197 |
utils.RunCmd(["fuser", "-k", "-KILL", "-m", root_dir]) |
198 |
# 2 seconds at most should be enough for KILL to take action
|
199 |
time.sleep(2)
|
200 |
|
201 |
if self._IsDirLive(root_dir): |
202 |
if force:
|
203 |
raise HypervisorError("Can't stop the processes using the chroot") |
204 |
return
|
205 |
|
206 |
for mpath in self._GetMountSubdirs(root_dir): |
207 |
utils.RunCmd(["umount", mpath])
|
208 |
|
209 |
result = utils.RunCmd(["umount", root_dir])
|
210 |
if result.failed and force: |
211 |
msg = ("Processes still alive in the chroot: %s" %
|
212 |
utils.RunCmd("fuser -vm %s" % root_dir).output)
|
213 |
logging.error(msg) |
214 |
raise HypervisorError("Can't umount the chroot dir: %s (%s)" % |
215 |
(result.output, msg)) |
216 |
|
217 |
def RebootInstance(self, instance): |
218 |
"""Reboot an instance.
|
219 |
|
220 |
This is not (yet) implemented for the chroot manager.
|
221 |
|
222 |
"""
|
223 |
raise HypervisorError("The chroot manager doesn't implement the" |
224 |
" reboot functionality")
|
225 |
|
226 |
def GetNodeInfo(self): |
227 |
"""Return information about the node.
|
228 |
|
229 |
This is just a wrapper over the base GetLinuxNodeInfo method.
|
230 |
|
231 |
@return: a dict with the following keys (values in MiB):
|
232 |
- memory_total: the total memory size on the node
|
233 |
- memory_free: the available memory on the node for instances
|
234 |
- memory_dom0: the memory used by the node itself, if available
|
235 |
|
236 |
"""
|
237 |
return self.GetLinuxNodeInfo() |
238 |
|
239 |
@classmethod
|
240 |
def GetShellCommandForConsole(cls, instance, hvparams, beparams): |
241 |
"""Return a command for connecting to the console of an instance.
|
242 |
|
243 |
"""
|
244 |
root_dir = "%s/%s" % (cls._ROOT_DIR, instance.name)
|
245 |
if not os.path.ismount(root_dir): |
246 |
raise HypervisorError("Instance %s is not running" % instance.name) |
247 |
|
248 |
return "chroot %s" % root_dir |
249 |
|
250 |
def Verify(self): |
251 |
"""Verify the hypervisor.
|
252 |
|
253 |
For the chroot manager, it just checks the existence of the base dir.
|
254 |
|
255 |
"""
|
256 |
if not os.path.exists(self._ROOT_DIR): |
257 |
return "The required directory '%s' does not exist." % self._ROOT_DIR |