4 # Copyright (C) 2006, 2007, 2008, 2009 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 """Chroot manager hypervisor
31 from ganeti import constants
32 from ganeti import errors # pylint: disable-msg=W0611
33 from ganeti import utils
34 from ganeti.hypervisor import hv_base
35 from ganeti.errors import HypervisorError
38 class ChrootManager(hv_base.BaseHypervisor):
41 This not-really hypervisor allows ganeti to manage chroots. It has
42 special behaviour and requirements on the OS definition and the node
44 - the start and stop of the chroot environment are done via a
45 script called ganeti-chroot located in the root directory of the
46 first drive, which should be created by the OS definition
47 - this script must accept the start and stop argument and, on
48 shutdown, it should cleanly shutdown the daemons/processes
50 - the daemons run in chroot should only bind to the instance IP
51 (to which the OS create script has access via the instance name)
52 - since some daemons in the node could be listening on the wildcard
53 address, some ports might be unavailable
54 - the instance listing will show no memory usage
55 - on shutdown, the chroot manager will try to find all mountpoints
56 under the root dir of the instance and unmount them
57 - instance alive check is based on whether any process is using the chroot
60 _ROOT_DIR = constants.RUN_GANETI_DIR + "/chroot-hypervisor"
63 constants.HV_INIT_SCRIPT: (True, utils.IsNormAbsPath,
64 "must be an absolute normalized path",
69 hv_base.BaseHypervisor.__init__(self)
70 utils.EnsureDirs([(self._ROOT_DIR, constants.RUN_DIRS_MODE)])
74 """Check if a directory looks like a live chroot.
77 if not os.path.ismount(path):
79 result = utils.RunCmd(["fuser", "-m", path])
80 return not result.failed
83 def _GetMountSubdirs(path):
84 """Return the list of mountpoints under a given path.
88 for _, mountpoint, _, _ in utils.GetMounts():
89 if (mountpoint.startswith(path) and
91 result.append(mountpoint)
93 result.sort(key=lambda x: x.count("/"), reverse=True)
97 def _InstanceDir(cls, instance_name):
98 """Return the root directory for an instance.
101 return utils.PathJoin(cls._ROOT_DIR, instance_name)
103 def ListInstances(self):
104 """Get the list of running instances.
107 return [name for name in os.listdir(self._ROOT_DIR)
108 if self._IsDirLive(utils.PathJoin(self._ROOT_DIR, name))]
110 def GetInstanceInfo(self, instance_name):
111 """Get instance properties.
113 @type instance_name: string
114 @param instance_name: the instance name
116 @return: (name, id, memory, vcpus, stat, times)
119 dir_name = self._InstanceDir(instance_name)
120 if not self._IsDirLive(dir_name):
121 raise HypervisorError("Instance %s is not running" % instance_name)
122 return (instance_name, 0, 0, 0, 0, 0)
124 def GetAllInstancesInfo(self):
125 """Get properties of all instances.
127 @return: [(name, id, memory, vcpus, stat, times),...]
131 for file_name in os.listdir(self._ROOT_DIR):
132 path = utils.PathJoin(self._ROOT_DIR, file_name)
133 if self._IsDirLive(path):
134 data.append((file_name, 0, 0, 0, 0, 0))
137 def StartInstance(self, instance, block_devices):
138 """Start an instance.
140 For the chroot manager, we try to mount the block device and
141 execute '/ganeti-chroot start'.
144 root_dir = self._InstanceDir(instance.name)
145 if not os.path.exists(root_dir):
149 raise HypervisorError("Failed to start instance %s: %s" %
150 (instance.name, err))
151 if not os.path.isdir(root_dir):
152 raise HypervisorError("Needed path %s is not a directory" % root_dir)
154 if not os.path.ismount(root_dir):
155 if not block_devices:
156 raise HypervisorError("The chroot manager needs at least one disk")
158 sda_dev_path = block_devices[0][1]
159 result = utils.RunCmd(["mount", sda_dev_path, root_dir])
161 raise HypervisorError("Can't mount the chroot dir: %s" % result.output)
162 init_script = instance.hvparams[constants.HV_INIT_SCRIPT]
163 result = utils.RunCmd(["chroot", root_dir, init_script, "start"])
165 raise HypervisorError("Can't run the chroot start script: %s" %
168 def StopInstance(self, instance, force=False, retry=False, name=None):
171 This method has complicated cleanup tests, as we must:
172 - try to kill all leftover processes
173 - try to unmount any additional sub-mountpoints
174 - finally unmount the instance dir
180 root_dir = self._InstanceDir(name)
181 if not os.path.exists(root_dir) or not self._IsDirLive(root_dir):
184 # Run the chroot stop script only once
185 if not retry and not force:
186 result = utils.RunCmd(["chroot", root_dir, "/ganeti-chroot", "stop"])
188 raise HypervisorError("Can't run the chroot stop script: %s" %
192 utils.RunCmd(["fuser", "-k", "-TERM", "-m", root_dir])
194 utils.RunCmd(["fuser", "-k", "-KILL", "-m", root_dir])
195 # 2 seconds at most should be enough for KILL to take action
198 if self._IsDirLive(root_dir):
200 raise HypervisorError("Can't stop the processes using the chroot")
203 def CleanupInstance(self, instance_name):
204 """Cleanup after a stopped instance
207 root_dir = self._InstanceDir(instance_name)
209 if not os.path.exists(root_dir):
212 if self._IsDirLive(root_dir):
213 raise HypervisorError("Processes are still using the chroot")
215 for mpath in self._GetMountSubdirs(root_dir):
216 utils.RunCmd(["umount", mpath])
218 result = utils.RunCmd(["umount", root_dir])
220 msg = ("Processes still alive in the chroot: %s" %
221 utils.RunCmd("fuser -vm %s" % root_dir).output)
223 raise HypervisorError("Can't umount the chroot dir: %s (%s)" %
224 (result.output, msg))
226 def RebootInstance(self, instance):
227 """Reboot an instance.
229 This is not (yet) implemented for the chroot manager.
232 raise HypervisorError("The chroot manager doesn't implement the"
233 " reboot functionality")
235 def GetNodeInfo(self):
236 """Return information about the node.
238 This is just a wrapper over the base GetLinuxNodeInfo method.
240 @return: a dict with the following keys (values in MiB):
241 - memory_total: the total memory size on the node
242 - memory_free: the available memory on the node for instances
243 - memory_dom0: the memory used by the node itself, if available
246 return self.GetLinuxNodeInfo()
249 def GetShellCommandForConsole(cls, instance, hvparams, beparams):
250 """Return a command for connecting to the console of an instance.
253 root_dir = cls._InstanceDir(instance.name)
254 if not os.path.ismount(root_dir):
255 raise HypervisorError("Instance %s is not running" % instance.name)
257 return "chroot %s" % root_dir
260 """Verify the hypervisor.
262 For the chroot manager, it just checks the existence of the base dir.
265 if not os.path.exists(self._ROOT_DIR):
266 return "The required directory '%s' does not exist." % self._ROOT_DIR
269 def PowercycleNode(cls):
270 """Chroot powercycle, just a wrapper over Linux powercycle.
273 cls.LinuxPowercycle()
275 def MigrateInstance(self, instance, target, live):
276 """Migrate an instance.
278 @type instance: L{objects.Instance}
279 @param instance: the instance to be migrated
281 @param target: hostname (usually ip) of the target node
283 @param live: whether to do a live or non-live migration
286 raise HypervisorError("Migration not supported by the chroot hypervisor")