4 # Copyright (C) 2010 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
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 LXCHypervisor(hv_base.BaseHypervisor):
39 """LXC-based virtualization.
41 Since current (Spring 2010) distributions are not yet ready for
42 running under a container, the following changes must be done
45 - disable the kernel log component of sysklogd/rsyslog/etc.,
46 otherwise they will fail to read the log, and at least rsyslog
47 will fill the filesystem with error messages
50 - move hardcoded parameters into hypervisor parameters, once we
51 have the container-parameter support
52 - implement memory limits, but only optionally, depending on host
56 - LXC is very temperamental; in daemon mode, it succeeds or fails
57 in launching the instance silently, without any error
58 indication, and when failing it can leave network interfaces
59 around, and future successful startups will list the instance
61 - shutdown sequence of containers leaves the init 'dead', and the
62 container effectively stopped, but LXC still believes the
63 container to be running; need to investigate using the
64 notify_on_release and release_agent feature of cgroups
67 _ROOT_DIR = constants.RUN_GANETI_DIR + "/lxc"
68 _LOG_FILE = constants.LOG_DIR + "hv_lxc.log"
73 "c 1:8", # /dev/random
74 "c 1:9", # /dev/urandom
77 "c 5:1", # /dev/console
79 "c 136:*", # first block of Unix98 PTY slaves
81 _DENIED_CAPABILITIES = [
82 "mac_override", # Allow MAC configuration or state changes
83 # TODO: remove sys_admin too, for safety
84 #"sys_admin", # Perform a range of system administration operations
85 "sys_boot", # Use reboot(2) and kexec_load(2)
86 "sys_module", # Load and unload kernel modules
87 "sys_time", # Set system clock, set real-time (hardware) clock
95 hv_base.BaseHypervisor.__init__(self)
96 utils.EnsureDirs([(self._ROOT_DIR, self._DIR_MODE)])
99 def _GetMountSubdirs(path):
100 """Return the list of mountpoints under a given path.
104 for _, mountpoint, _, _ in utils.GetMounts():
105 if (mountpoint.startswith(path) and
107 result.append(mountpoint)
109 result.sort(key=lambda x: x.count("/"), reverse=True)
113 def _InstanceDir(cls, instance_name):
114 """Return the root directory for an instance.
117 return utils.PathJoin(cls._ROOT_DIR, instance_name)
120 def _InstanceConfFile(cls, instance_name):
121 """Return the configuration file for an instance.
124 return utils.PathJoin(cls._ROOT_DIR, instance_name + ".conf")
126 def ListInstances(self):
127 """Get the list of running instances.
130 result = utils.RunCmd(["lxc-ls"])
132 raise errors.HypervisorError("Can't run lxc-ls: %s" % result.output)
133 return result.stdout.splitlines()
135 def GetInstanceInfo(self, instance_name):
136 """Get instance properties.
138 @type instance_name: string
139 @param instance_name: the instance name
141 @return: (name, id, memory, vcpus, stat, times)
144 # TODO: read container info from the cgroup mountpoint
145 return (instance_name, 0, 0, 0, 0, 0)
147 def GetAllInstancesInfo(self):
148 """Get properties of all instances.
150 @return: [(name, id, memory, vcpus, stat, times),...]
153 # TODO: read container info from the cgroup mountpoint
155 for name in self.ListInstances():
156 data.append((name, 0, 0, 0, 0, 0))
159 def _CreateConfigFile(self, instance, root_dir):
160 """Create an lxc.conf file for an instance"""
163 out.append("lxc.utsname = %s" % instance.name)
165 # separate pseudo-TTY instances
166 out.append("lxc.pts = 255")
167 # standard TTYs/console
168 out.append("lxc.tty = 6")
171 out.append("lxc.rootfs = %s" % root_dir)
173 # TODO: additional mounts, if we disable CAP_SYS_ADMIN
176 # deny direct device access
177 out.append("lxc.cgroup.devices.deny = a")
178 for devinfo in self._DEVS:
179 out.append("lxc.cgroup.devices.allow = %s rw" % devinfo)
182 for idx, nic in enumerate(instance.nics):
183 out.append("# NIC %d" % idx)
184 mode = nic.nicparams[constants.NIC_MODE]
185 link = nic.nicparams[constants.NIC_LINK]
186 if mode == constants.NIC_MODE_BRIDGED:
187 out.append("lxc.network.type = veth")
188 out.append("lxc.network.link = %s" % link)
190 raise errors.HypervisorError("LXC hypervisor only supports"
191 " bridged mode (NIC %d has mode %s)" %
193 out.append("lxc.network.hwaddr = %s" % nic.mac)
194 out.append("lxc.network.flags = up")
197 for cap in self._DENIED_CAPABILITIES:
198 out.append("lxc.cap.drop = %s" % cap)
200 return "\n".join(out) + "\n"
202 def StartInstance(self, instance, block_devices):
203 """Start an instance.
205 For LCX, we try to mount the block device and execute 'lxc-start
206 start' (we use volatile containers).
209 root_dir = self._InstanceDir(instance.name)
211 utils.EnsureDirs([(root_dir, self._DIR_MODE)])
212 except errors.GenericError, err:
213 raise HypervisorError("Cannot create instance directory: %s", str(err))
215 conf_file = self._InstanceConfFile(instance.name)
216 utils.WriteFile(conf_file, data=self._CreateConfigFile(instance, root_dir))
218 if not os.path.ismount(root_dir):
219 if not block_devices:
220 raise HypervisorError("LXC needs at least one disk")
222 sda_dev_path = block_devices[0][1]
223 result = utils.RunCmd(["mount", sda_dev_path, root_dir])
225 raise HypervisorError("Can't mount the chroot dir: %s" % result.output)
226 # TODO: replace the global log file with a per-instance log file
227 result = utils.RunCmd(["lxc-start", "-n", instance.name,
228 "-o", self._LOG_FILE, "-l", "DEBUG",
229 "-f", conf_file, "-d"])
231 raise HypervisorError("Running the lxc-start script failed: %s" %
234 def StopInstance(self, instance, force=False, retry=False, name=None):
237 This method has complicated cleanup tests, as we must:
238 - try to kill all leftover processes
239 - try to unmount any additional sub-mountpoints
240 - finally unmount the instance dir
246 root_dir = self._InstanceDir(name)
247 if not os.path.exists(root_dir):
250 if name in self.ListInstances():
251 # Signal init to shutdown; this is a hack
252 if not retry and not force:
253 result = utils.RunCmd(["chroot", root_dir, "poweroff"])
255 raise HypervisorError("Can't run 'poweroff' for the instance: %s" %
258 result = utils.RunCmd(["lxc-stop", "-n", name])
260 logging.warning("Error while doing lxc-stop for %s: %s", name,
263 for mpath in self._GetMountSubdirs(root_dir):
264 result = utils.RunCmd(["umount", mpath])
266 logging.warning("Error while umounting subpath %s for instance %s: %s",
267 mpath, name, result.output)
269 result = utils.RunCmd(["umount", root_dir])
270 if result.failed and force:
271 msg = ("Processes still alive in the chroot: %s" %
272 utils.RunCmd("fuser -vm %s" % root_dir).output)
274 raise HypervisorError("Can't umount the chroot dir: %s (%s)" %
275 (result.output, msg))
277 def RebootInstance(self, instance):
278 """Reboot an instance.
280 This is not (yet) implemented (in Ganeti) for the LXC hypervisor.
283 # TODO: implement reboot
284 raise HypervisorError("The LXC hypervisor doesn't implement the"
285 " reboot functionality")
287 def GetNodeInfo(self):
288 """Return information about the node.
290 This is just a wrapper over the base GetLinuxNodeInfo method.
292 @return: a dict with the following keys (values in MiB):
293 - memory_total: the total memory size on the node
294 - memory_free: the available memory on the node for instances
295 - memory_dom0: the memory used by the node itself, if available
298 return self.GetLinuxNodeInfo()
301 def GetShellCommandForConsole(cls, instance, hvparams, beparams):
302 """Return a command for connecting to the console of an instance.
305 return "lxc-console -n %s" % instance.name
308 """Verify the hypervisor.
310 For the chroot manager, it just checks the existence of the base dir.
313 if not os.path.exists(self._ROOT_DIR):
314 return "The required directory '%s' does not exist." % self._ROOT_DIR
317 def PowercycleNode(cls):
318 """LXC powercycle, just a wrapper over Linux powercycle.
321 cls.LinuxPowercycle()
323 def MigrateInstance(self, instance, target, live):
324 """Migrate an instance.
326 @type instance: L{objects.Instance}
327 @param instance: the instance to be migrated
329 @param target: hostname (usually ip) of the target node
331 @param live: whether to do a live or non-live migration
334 raise HypervisorError("Migration not supported by the LXC hypervisor")