ganeti :: hypervisor :: hv_lxc :: LXCHypervisor :: Class LXCHypervisor

Class LXCHypervisor

LXC-based virtualization.

Since current (Spring 2010) distributions are not yet ready for running under a container, the following changes must be done manually:

remove udev
disable the kernel log component of sysklogd/rsyslog/etc., otherwise they will fail to read the log, and at least rsyslog will fill the filesystem with error messages

TODO:

move hardcoded parameters into hypervisor parameters, once we have the container-parameter support
implement memory limits, but only optionally, depending on host kernel support

Problems/issues:

LXC is very temperamental; in daemon mode, it succeeds or fails in launching the instance silently, without any error indication, and when failing it can leave network interfaces around, and future successful startups will list the instance twice
shutdown sequence of containers leaves the init 'dead', and the container effectively stopped, but LXC still believes the container to be running; need to investigate using the notify_on_release and release_agent feature of cgroups

Instance Methods

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__init__(self)
x.__init__(...) initializes x; see x.__class__.__doc__ for signature

source code

ListInstances(self)
Get the list of running instances.

source code

GetInstanceInfo(self, instance_name)
Get instance properties.

source code

GetAllInstancesInfo(self)
Get properties of all instances.

source code

_CreateConfigFile(self, instance, root_dir)
Create an lxc.conf file for an instance.

source code

StartInstance(self, instance, block_devices, startup_paused)
Start an instance.

source code

StopInstance(self, instance, force=False, retry=False, name=None)
Stop an instance.

source code

RebootInstance(self, instance)
Reboot an instance.

source code

GetNodeInfo(self)
Return information about the node.

source code

Verify(self)
Verify the hypervisor.

source code

MigrateInstance(self, instance, target, live)
Migrate an instance.

source code

Inherited from hv_base.BaseHypervisor: AcceptInstance, CleanupInstance, FinalizeMigration, MigrationInfo

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__

Class Methods

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_InstanceDir(cls, instance_name)
Return the root directory for an instance.

source code

_InstanceConfFile(cls, instance_name)
Return the configuration file for an instance.

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_InstanceLogFile(cls, instance_name)
Return the log file for an instance.

source code

_GetCgroupMountPoint(cls)

source code

_GetCgroupCpuList(cls, instance_name)
Return the list of CPU ids for an instance.

source code

GetInstanceConsole(cls, instance, hvparams, beparams)
Return a command for connecting to the console of an instance.

source code

PowercycleNode(cls)
LXC powercycle, just a wrapper over Linux powercycle.

source code

Inherited from hv_base.BaseHypervisor: CheckParameterSyntax, GetAncillaryFiles, LinuxPowercycle, ValidateParameters

Static Methods

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_GetMountSubdirs(path)
Return the list of mountpoints under a given path.

source code

Inherited from hv_base.BaseHypervisor: GetLinuxNodeInfo

Class Variables

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_ROOT_DIR = constants.RUN_GANETI_DIR+ "/lxc"

_DEVS = ["c 1:3", "c 1:5", "c 1:7", "c 1:8", "c 1:9", "c 1:10"...

_DENIED_CAPABILITIES = ["mac_override", "sys_boot", "sys_modul...

_DIR_MODE = 0755

PARAMETERS = {constants.HV_CPU_MASK: hv_base.OPT_CPU_MASK_CHECK,}
a dict of parameter name: check type; the check type is a five-tuple containing:

Inherited from hv_base.BaseHypervisor: ANCILLARY_FILES, CAN_MIGRATE

Properties

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Inherited from object: __class__

Method Details

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init(self)
(Constructor)

source code

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

Overrides: object.__init__: (inherited documentation)

ListInstances(self)

source code

Get the list of running instances.

Overrides: hv_base.BaseHypervisor.ListInstances

GetInstanceInfo(self, instance_name)

source code

Get instance properties.

Parameters:

instance_name (string) - the instance name

Returns:

(name, id, memory, vcpus, stat, times)

Overrides: hv_base.BaseHypervisor.GetInstanceInfo

GetAllInstancesInfo(self)

source code

Get properties of all instances.

Returns:: [(name, id, memory, vcpus, stat, times),...]
Overrides: hv_base.BaseHypervisor.GetAllInstancesInfo

StartInstance(self, instance, block_devices, startup_paused)

source code

Start an instance.

For LCX, we try to mount the block device and execute 'lxc-start'. We use volatile containers.

Overrides: hv_base.BaseHypervisor.StartInstance

StopInstance(self, instance, force=False, retry=False, name=None)

source code

Stop an instance.

This method has complicated cleanup tests, as we must:

try to kill all leftover processes
try to unmount any additional sub-mountpoints
finally unmount the instance dir

Parameters:

instance - instance to stop
force - whether to do a "hard" stop (destroy)
retry - whether this is just a retry call
name - if this parameter is passed, the the instance object should not be used (will be passed as None), and the shutdown must be done by name only

Overrides: hv_base.BaseHypervisor.StopInstance

RebootInstance(self, instance)

source code

Reboot an instance.

This is not (yet) implemented (in Ganeti) for the LXC hypervisor.

Overrides: hv_base.BaseHypervisor.RebootInstance

GetNodeInfo(self)

source code

Return information about the node.

This is just a wrapper over the base GetLinuxNodeInfo method.

Returns:

a dict with the following keys (values in MiB):

memory_total: the total memory size on the node
memory_free: the available memory on the node for instances
memory_dom0: the memory used by the node itself, if available

Overrides: hv_base.BaseHypervisor.GetNodeInfo

GetInstanceConsole(cls, instance, hvparams, beparams)
Class Method

source code

Return a command for connecting to the console of an instance.

Overrides: hv_base.BaseHypervisor.GetInstanceConsole

Verify(self)

source code

Verify the hypervisor.

For the chroot manager, it just checks the existence of the base dir.

Overrides: hv_base.BaseHypervisor.Verify

PowercycleNode(cls)
Class Method

source code

LXC powercycle, just a wrapper over Linux powercycle.

Overrides: hv_base.BaseHypervisor.PowercycleNode

MigrateInstance(self, instance, target, live)

source code

Migrate an instance.

Parameters:

instance (objects.Instance) - the instance to be migrated
target (string) - hostname (usually ip) of the target node
live (boolean) - whether to do a live or non-live migration

Overrides: hv_base.BaseHypervisor.MigrateInstance

Class Variable Details

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_DEVS

Value:

["c 1:3", "c 1:5", "c 1:7", "c 1:8", "c 1:9", "c 1:10", "c 5:0", "c 5:
1", "c 5:2", "c 136:*",]

_DENIED_CAPABILITIES

Value:

["mac_override", "sys_boot", "sys_module", "sys_time",]

Class LXCHypervisor

__init__(self) (Constructor)

ListInstances(self)

GetInstanceInfo(self, instance_name)

GetAllInstancesInfo(self)

StartInstance(self, instance, block_devices, startup_paused)

StopInstance(self, instance, force=False, retry=False, name=None)

RebootInstance(self, instance)

GetNodeInfo(self)

GetInstanceConsole(cls, instance, hvparams, beparams) Class Method

Verify(self)

PowercycleNode(cls) Class Method

MigrateInstance(self, instance, target, live)

_DEVS

_DENIED_CAPABILITIES

init(self)
(Constructor)

GetInstanceConsole(cls, instance, hvparams, beparams)
Class Method

PowercycleNode(cls)
Class Method