The nova.virt.libvirt.connection Module

A connection to a hypervisor through libvirt.

Supports KVM, LXC, QEMU, UML, and XEN.

Related Flags

libvirt_type:Libvirt domain type. Can be kvm, qemu, uml, xen (default: kvm). libvirt_uri:Override for the default libvirt URI (depends on libvirt_type). libvirt_xml_template:  Libvirt XML Template. rescue_image_id:  Rescue ami image (None = original image). rescue_kernel_id:  Rescue aki image (None = original image). rescue_ramdisk_id:  Rescue ari image (None = original image). injected_network_template:  Template file for injected network allow_same_net_traffic:  Whether to allow in project network traffic

class nova.virt.libvirt.connection.ConsoleLogger(fifo_path, ringbuffer_path)

Bases: object

close()

peek()

class nova.virt.libvirt.connection.LibvirtConnection(read_only)

Bases: nova.virt.driver.ComputeDriver

attach_volume(*args, **kw)

block_stats(instance_name, disk)

Note that this function takes an instance name.

compare_cpu(cpu_info)

Checks the host cpu is compatible to a cpu given by xml.

“xml” must be a part of libvirt.openReadonly().getCapabilities(). return values follows by virCPUCompareResult. if 0 > return value, do live migration. ‘http://libvirt.org/html/libvirt-libvirt.html#virCPUCompareResult‘

Parameters:cpu_info – json string that shows cpu feature(see get_cpu_info()) Returns:None. if given cpu info is not compatible to this server, raise exception.

destroy(instance, network_info, cleanup=True)

detach_volume(*args, **kw)

ensure_filtering_rules_for_instance(instance_ref, network_info, time=None)

Setting up filtering rules and waiting for its completion.

To migrate an instance, filtering rules to hypervisors and firewalls are inevitable on destination host. ( Waiting only for filterling rules to hypervisor, since filtering rules to firewall rules can be set faster).

Concretely, the below method must be called. - setup_basic_filtering (for nova-basic, etc.) - prepare_instance_filter(for nova-instance-instance-xxx, etc.)

to_xml may have to be called since it defines PROJNET, PROJMASK. but libvirt migrates those value through migrateToURI(), so , no need to be called.

Don’t use thread for this method since migration should not be started when setting-up filtering rules operations are not completed.

Params instance_ref:  nova.db.sqlalchemy.models.Instance object

get_ajax_console(*args, **kw)

get_console_output(*args, **kw)

get_console_pool_info(console_type)

get_cpu_info()

Get cpuinfo information.

Obtains cpu feature from virConnect.getCapabilities, and returns as a json string.

Returns:see above description

get_diagnostics(instance_name)

get_disks(instance_name)

Note that this function takes an instance name.

Returns a list of all block devices for this domain.

get_host_ip_addr()

get_host_stats(refresh=False)

See xenapi_conn.py implementation.

get_hypervisor_type()

Get hypervisor type.

Returns:hypervisor type (ex. qemu)

get_hypervisor_version()

Get hypervisor version.

Returns:hypervisor version (ex. 12003)

get_info(instance_name)

Retrieve information from libvirt for a specific instance name.

If a libvirt error is encountered during lookup, we might raise a NotFound exception or Error exception depending on how severe the libvirt error is.

get_instance_disk_info(ctxt, instance_ref)

Preparation block migration.

Params ctxt:security context Params instance_ref:  nova.db.sqlalchemy.models.Instance object instance object that is migrated. Returns:

json strings with below format.

“[{‘path’:’disk’, ‘type’:’raw’, ‘local_gb’:‘10G’},...]”

get_interfaces(instance_name)

Note that this function takes an instance name.

Returns a list of all network interfaces for this instance.

get_local_gb_total()

Get the total hdd size(GB) of physical computer.

Returns:The total amount of HDD(GB). Note that this value shows a partition where NOVA-INST-DIR/instances mounts.

get_local_gb_used()

Get the free hdd size(GB) of physical computer.

Returns:The total usage of HDD(GB). Note that this value shows a partition where NOVA-INST-DIR/instances mounts.

get_memory_mb_total()

Get the total memory size(MB) of physical computer.

Returns:the total amount of memory(MB).

get_memory_mb_used()

Get the free memory size(MB) of physical computer.

Returns:the total usage of memory(MB).

get_uri()

get_vcpu_total()

Get vcpu number of physical computer.

Returns:the number of cpu core.

get_vcpu_used()

Get vcpu usage number of physical computer.

Returns:The total number of vcpu that currently used.

get_vnc_console(*args, **kw)

host_power_action(host, action)

Reboots, shuts down or powers up the host.

init_host(host)

interface_stats(instance_name, interface)

Note that this function takes an instance name.

list_instances()

list_instances_detail()

live_migration(ctxt, instance_ref, dest, post_method, recover_method, block_migration=False)

Spawning live_migration operation for distributing high-load.

Params ctxt:security context Params instance_ref:  nova.db.sqlalchemy.models.Instance object instance object that is migrated. Params dest:destination host Params block_migration:  destination host Params post_method:  post operation method. expected nova.compute.manager.post_live_migration. Params recover_method:  recovery method when any exception occurs. expected nova.compute.manager.recover_live_migration. Params block_migration:  if true, do block migration.

pause(*args, **kw)

Pause VM instance

plug_vifs(instance, network_info)

Plugin VIFs into networks.

poll_rescued_instances(*args, **kw)

post_live_migration_at_destination(ctxt, instance_ref, network_info, block_migration)

Post operation of live migration at destination host.

Params ctxt:security context Params instance_ref:  nova.db.sqlalchemy.models.Instance object instance object that is migrated. Params network_info:  instance network infomation

:params : block_migration: if true, post operation of block_migraiton.

pre_block_migration(ctxt, instance_ref, disk_info_json)

Preparation block migration.

Params ctxt:security context Params instance_ref:  nova.db.sqlalchemy.models.Instance object instance object that is migrated. Params disk_info_json:  json strings specified in get_instance_disk_info

reboot(*args, **kw)

Reboot a virtual machine, given an instance reference.

This method actually destroys and re-creates the domain to ensure the reboot happens, as the guest OS cannot ignore this action.

refresh_provider_fw_rules()

refresh_security_group_members(security_group_id)

refresh_security_group_rules(security_group_id)

rescue(*args, **kw)

Loads a VM using rescue images.

A rescue is normally performed when something goes wrong with the primary images and data needs to be corrected/recovered. Rescuing should not edit or over-ride the original image, only allow for data recovery.

resume(*args, **kw)

resume the specified instance

set_host_enabled(host, enabled)

Sets the specified host’s ability to accept new instances.

snapshot(*args, **kw)

Create snapshot from a running VM instance.

This command only works with qemu 0.14+

spawn(*args, **kw)

suspend(*args, **kw)

Suspend the specified instance

to_xml(instance, network_info, rescue=False, block_device_info=None)

unfilter_instance(instance_ref, network_info)

See comments of same method in firewall_driver.

unpause(*args, **kw)

Unpause paused VM instance

unrescue(*args, **kw)

Reboot the VM which is being rescued back into primary images.

Because reboot destroys and re-creates instances, unresue should simply call reboot.

update_available_resource(ctxt, host)

Updates compute manager resource info on ComputeNode table.

This method is called when nova-coompute launches, and whenever admin executes “nova-manage service update_resource”.

Parameters:

• ctxt – security context
• host – hostname that compute manager is currently running

update_host_status()

See xenapi_conn.py implementation.

nova.virt.libvirt.connection.get_connection(read_only)