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.
102 This function is Linux-specific.
105 #TODO(iustin): investigate and document non-linux options
106 #(e.g. via mount output)
108 fh = open("/proc/mounts", "r")
111 _, mountpoint, _ = line.split(" ", 2)
112 if (mountpoint.startswith(path) and
114 data.append(mountpoint)
117 data.sort(key=lambda x: x.count("/"), reverse=True)
121 def _InstanceDir(cls, instance_name):
122 """Return the root directory for an instance.
125 return utils.PathJoin(cls._ROOT_DIR, instance_name)
128 def _InstanceConfFile(cls, instance_name):
129 """Return the configuration file for an instance.
132 return utils.PathJoin(cls._ROOT_DIR, instance_name + ".conf")
134 def ListInstances(self):
135 """Get the list of running instances.
138 result = utils.RunCmd(["lxc-ls"])
140 raise errors.HypervisorError("Can't run lxc-ls: %s" % result.output)
141 return result.stdout.splitlines()
143 def GetInstanceInfo(self, instance_name):
144 """Get instance properties.
146 @type instance_name: string
147 @param instance_name: the instance name
149 @return: (name, id, memory, vcpus, stat, times)
152 # TODO: read container info from the cgroup mountpoint
153 return (instance_name, 0, 0, 0, 0, 0)
155 def GetAllInstancesInfo(self):
156 """Get properties of all instances.
158 @return: [(name, id, memory, vcpus, stat, times),...]
161 # TODO: read container info from the cgroup mountpoint
163 for name in self.ListInstances():
164 data.append((name, 0, 0, 0, 0, 0))
167 def _CreateConfigFile(self, instance, root_dir):
168 """Create an lxc.conf file for an instance"""
171 out.append("lxc.utsname = %s" % instance.name)
173 # separate pseudo-TTY instances
174 out.append("lxc.pts = 255")
175 # standard TTYs/console
176 out.append("lxc.tty = 6")
179 out.append("lxc.rootfs = %s" % root_dir)
181 # TODO: additional mounts, if we disable CAP_SYS_ADMIN
184 # deny direct device access
185 out.append("lxc.cgroup.devices.deny = a")
186 for devinfo in self._DEVS:
187 out.append("lxc.cgroup.devices.allow = %s rw" % devinfo)
190 for idx, nic in enumerate(instance.nics):
191 out.append("# NIC %d" % idx)
192 mode = nic.nicparams[constants.NIC_MODE]
193 link = nic.nicparams[constants.NIC_LINK]
194 if mode == constants.NIC_MODE_BRIDGED:
195 out.append("lxc.network.type = veth")
196 out.append("lxc.network.link = %s" % link)
198 raise errors.HypervisorError("LXC hypervisor only supports"
199 " bridged mode (NIC %d has mode %s)" %
201 out.append("lxc.network.hwaddr = %s" % nic.mac)
202 out.append("lxc.network.flags = up")
205 for cap in self._DENIED_CAPABILITIES:
206 out.append("lxc.cap.drop = %s" % cap)
208 return "\n".join(out) + "\n"
210 def StartInstance(self, instance, block_devices):
211 """Start an instance.
213 For LCX, we try to mount the block device and execute 'lxc-start
214 start' (we use volatile containers).
217 root_dir = self._InstanceDir(instance.name)
219 utils.EnsureDirs([(root_dir, self._DIR_MODE)])
220 except errors.GenericError, err:
221 raise HypervisorError("Cannot create instance directory: %s", str(err))
223 conf_file = self._InstanceConfFile(instance.name)
224 utils.WriteFile(conf_file, data=self._CreateConfigFile(instance, root_dir))
226 if not os.path.ismount(root_dir):
227 if not block_devices:
228 raise HypervisorError("LXC needs at least one disk")
230 sda_dev_path = block_devices[0][1]
231 result = utils.RunCmd(["mount", sda_dev_path, root_dir])
233 raise HypervisorError("Can't mount the chroot dir: %s" % result.output)
234 # TODO: replace the global log file with a per-instance log file
235 result = utils.RunCmd(["lxc-start", "-n", instance.name,
236 "-o", self._LOG_FILE, "-l", "DEBUG",
237 "-f", conf_file, "-d"])
239 raise HypervisorError("Running the lxc-start script failed: %s" %
242 def StopInstance(self, instance, force=False, retry=False, name=None):
245 This method has complicated cleanup tests, as we must:
246 - try to kill all leftover processes
247 - try to unmount any additional sub-mountpoints
248 - finally unmount the instance dir
254 root_dir = self._InstanceDir(name)
255 if not os.path.exists(root_dir):
258 if name in self.ListInstances():
259 # Signal init to shutdown; this is a hack
260 if not retry and not force:
261 result = utils.RunCmd(["chroot", root_dir, "poweroff"])
263 raise HypervisorError("Can't run 'poweroff' for the instance: %s" %
266 result = utils.RunCmd(["lxc-stop", "-n", name])
268 logging.warning("Error while doing lxc-stop for %s: %s", name,
271 for mpath in self._GetMountSubdirs(root_dir):
272 result = utils.RunCmd(["umount", mpath])
274 logging.warning("Error while umounting subpath %s for instance %s: %s",
275 mpath, name, result.output)
277 result = utils.RunCmd(["umount", root_dir])
278 if result.failed and force:
279 msg = ("Processes still alive in the chroot: %s" %
280 utils.RunCmd("fuser -vm %s" % root_dir).output)
282 raise HypervisorError("Can't umount the chroot dir: %s (%s)" %
283 (result.output, msg))
285 def RebootInstance(self, instance):
286 """Reboot an instance.
288 This is not (yet) implemented (in Ganeti) for the LXC hypervisor.
291 # TODO: implement reboot
292 raise HypervisorError("The LXC hypervisor doesn't implement the"
293 " reboot functionality")
295 def GetNodeInfo(self):
296 """Return information about the node.
298 This is just a wrapper over the base GetLinuxNodeInfo method.
300 @return: a dict with the following keys (values in MiB):
301 - memory_total: the total memory size on the node
302 - memory_free: the available memory on the node for instances
303 - memory_dom0: the memory used by the node itself, if available
306 return self.GetLinuxNodeInfo()
309 def GetShellCommandForConsole(cls, instance, hvparams, beparams):
310 """Return a command for connecting to the console of an instance.
313 return "lxc-console -n %s" % instance.name
316 """Verify the hypervisor.
318 For the chroot manager, it just checks the existence of the base dir.
321 if not os.path.exists(self._ROOT_DIR):
322 return "The required directory '%s' does not exist." % self._ROOT_DIR
325 def PowercycleNode(cls):
326 """LXC powercycle, just a wrapper over Linux powercycle.
329 cls.LinuxPowercycle()
331 def MigrateInstance(self, instance, target, live):
332 """Migrate an instance.
334 @type instance: L{objects.Instance}
335 @param instance: the instance to be migrated
337 @param target: hostname (usually ip) of the target node
339 @param live: whether to do a live or non-live migration
342 raise HypervisorError("Migration not supported by the LXC hypervisor")