The `nova.virt.driver` Module¶

Driver base-classes:

(Beginning of) the contract that compute drivers must follow, and shared types that support that contract

class ComputeDriver(virtapi)¶

Bases: object

Base class for compute drivers.

The interface to this class talks in terms of ‘instances’ (Amazon EC2 and internal Nova terminology), by which we mean ‘running virtual machine’ (XenAPI terminology) or domain (Xen or libvirt terminology).

An instance has an ID, which is the identifier chosen by Nova to represent the instance further up the stack. This is unfortunately also called a ‘name’ elsewhere. As far as this layer is concerned, ‘instance ID’ and ‘instance name’ are synonyms.

Note that the instance ID or name is not human-readable or customer-controlled – it’s an internal ID chosen by Nova. At the nova.virt layer, instances do not have human-readable names at all – such things are only known higher up the stack.

Most virtualization platforms will also have their own identity schemes, to uniquely identify a VM or domain. These IDs must stay internal to the platform-specific layer, and never escape the connection interface. The platform-specific layer is responsible for keeping track of which instance ID maps to which platform-specific ID, and vice versa.

Some methods here take an instance of nova.compute.service.Instance. This is the data structure used by nova.compute to store details regarding an instance, and pass them into this layer. This layer is responsible for translating that generic data structure into terms that are specific to the virtualization platform.

add_to_aggregate(context, aggregate, host, **kwargs)¶: Add a compute host to an aggregate.

attach_interface(instance, image_meta, vif)¶

Attach an interface to the instance.

Parameters:	instance – nova.objects.instance.Instance

attach_volume(context, connection_info, instance, mountpoint, disk_bus=None, device_type=None, encryption=None)¶: Attach the disk to the instance at mountpoint using info.

block_stats(instance, disk_id)¶

Return performance counters associated with the given disk_id on the given instance. These are returned as [rd_req, rd_bytes, wr_req, wr_bytes, errs], where rd indicates read, wr indicates write, req is the total number of I/O requests made, bytes is the total number of bytes transferred, and errs is the number of requests held up due to a full pipeline.

All counters are long integers.

This method is optional. On some platforms (e.g. XenAPI) performance statistics can be retrieved directly in aggregate form, without Nova having to do the aggregation. On those platforms, this method is unused.

Note that this function takes an instance ID.

capabilities = {'supports_migrate_to_same_host': False, 'has_imagecache': False, 'supports_recreate': False}¶

change_instance_metadata(context, instance, diff)¶

Applies a diff to the instance metadata.

This is an optional driver method which is used to publish changes to the instance’s metadata to the hypervisor. If the hypervisor has no means of publishing the instance metadata to the instance, then this method should not be implemented.

Parameters:	context – security context instance – nova.objects.instance.Instance

check_can_live_migrate_destination(context, instance, src_compute_info, dst_compute_info, block_migration=False, disk_over_commit=False)¶

Check if it is possible to execute live migration.

This runs checks on the destination host, and then calls back to the source host to check the results.

Parameters:	context – security context instance – nova.db.sqlalchemy.models.Instance src_compute_info – Info about the sending machine dst_compute_info – Info about the receiving machine block_migration – if true, prepare for block migration disk_over_commit – if true, allow disk over commit
Returns:	a dict containing migration info (hypervisor-dependent)

check_can_live_migrate_destination_cleanup(context, dest_check_data)¶

Do required cleanup on dest host after check_can_live_migrate calls

Parameters:	context – security context dest_check_data – result of check_can_live_migrate_destination

check_can_live_migrate_source(context, instance, dest_check_data, block_device_info=None)¶

Check if it is possible to execute live migration.

This checks if the live migration can succeed, based on the results from check_can_live_migrate_destination.

Parameters:	context – security context instance – nova.db.sqlalchemy.models.Instance dest_check_data – result of check_can_live_migrate_destination block_device_info – result of _get_instance_block_device_info
Returns:	a dict containing migration info (hypervisor-dependent)

check_instance_shared_storage_cleanup(context, data)¶

Do cleanup on host after check_instance_shared_storage calls

Parameters:	context – security context data – result of check_instance_shared_storage_local

check_instance_shared_storage_local(context, instance)¶

Check if instance files located on shared storage.

This runs check on the destination host, and then calls back to the source host to check the results.

Parameters:	context – security context instance – nova.objects.instance.Instance object

check_instance_shared_storage_remote(context, data)¶

Check if instance files located on shared storage.

Parameters:	context – security context data – result of check_instance_shared_storage_local

cleanup(context, instance, network_info, block_device_info=None, destroy_disks=True, migrate_data=None, destroy_vifs=True)¶

Cleanup the instance resources .

Instance should have been destroyed from the Hypervisor before calling this method.

Parameters:	context – security context instance – Instance object as returned by DB layer. network_info – `get_instance_nw_info()` block_device_info – Information about block devices that should be detached from the instance. destroy_disks – Indicates if disks should be destroyed migrate_data – implementation specific params

cleanup_host(host)¶: Clean up anything that is necessary for the driver gracefully stop, including ending remote sessions. This is optional.

confirm_migration(migration, instance, network_info)¶

Confirms a resize, destroying the source VM.

Parameters:	instance – nova.objects.instance.Instance

deallocate_networks_on_reschedule(instance)¶: Does the driver want networks deallocated on reschedule?

default_device_names_for_instance(instance, root_device_name, *block_device_lists)¶: Default the missing device names in the block device mapping.

default_root_device_name(instance, image_meta, root_bdm)¶: Provide a default root device name for the driver.

delete_instance_files(instance)¶

Delete any lingering instance files for an instance.

Parameters:	instance – nova.objects.instance.Instance
Returns:	True if the instance was deleted from disk, False otherwise.

destroy(context, instance, network_info, block_device_info=None, destroy_disks=True, migrate_data=None)¶

Destroy the specified instance from the Hypervisor.

If the instance is not found (for example if networking failed), this function should still succeed. It’s probably a good idea to log a warning in that case.

Parameters:	context – security context instance – Instance object as returned by DB layer. network_info – `get_instance_nw_info()` block_device_info – Information about block devices that should be detached from the instance. destroy_disks – Indicates if disks should be destroyed migrate_data – implementation specific params

detach_interface(instance, vif)¶

Detach an interface from the instance.

Parameters:	instance – nova.objects.instance.Instance

detach_volume(connection_info, instance, mountpoint, encryption=None)¶: Detach the disk attached to the instance.

dhcp_options_for_instance(instance)¶

Get DHCP options for this instance.

Some hypervisors (such as bare metal) require that instances boot from the network, and manage their own TFTP service. This requires passing the appropriate options out to the DHCP service. Most hypervisors can use the default implementation which returns None.

This is called during spawn_instance by the compute manager.

Note that the format of the return value is specific to Quantum client API.

Returns:	None, or a set of DHCP options, eg: [{‘opt_name’: ‘bootfile-name’, ‘opt_value’: ‘/tftpboot/path/to/config’}, {‘opt_name’: ‘server-ip-address’, ‘opt_value’: ‘1.2.3.4’}, {‘opt_name’: ‘tftp-server’, ‘opt_value’: ‘1.2.3.4’} ]

emit_event(event)¶

Dispatches an event to the compute manager.

Invokes the event callback registered by the compute manager to dispatch the event. This must only be invoked from a green thread.

ensure_filtering_rules_for_instance(instance, network_info)¶

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 filtering 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.

Parameters:	instance – nova.objects.instance.Instance object

estimate_instance_overhead(instance_info)¶

Estimate the virtualization overhead required to build an instance of the given flavor.

Defaults to zero, drivers should override if per-instance overhead calculations are desired.

Parameters:	instance_info – Instance/flavor to calculate overhead for.
Returns:	Dict of estimated overhead values.

filter_defer_apply_off()¶: Turn off deferral of IPTables rules and apply the rules now.

filter_defer_apply_on()¶: Defer application of IPTables rules.

finish_migration(context, migration, instance, disk_info, network_info, image_meta, resize_instance, block_device_info=None, power_on=True)¶

Completes a resize.

Parameters:

context – the context for the migration/resize
migration – the migrate/resize information
instance – nova.objects.instance.Instance being migrated/resized
disk_info – the newly transferred disk information
network_info – get_instance_nw_info()
image_meta – image object returned by nova.image.glance that defines the image from which this instance was created
resize_instance – True if the instance is being resized, False otherwise
block_device_info – instance volume block device info
power_on – True if the instance should be powered on, False otherwise

finish_revert_migration(context, instance, network_info, block_device_info=None, power_on=True)¶

Finish reverting a resize.

Parameters:	context – the context for the finish_revert_migration instance – nova.objects.instance.Instance being migrated/resized network_info – `get_instance_nw_info()` block_device_info – instance volume block device info power_on – True if the instance should be powered on, False otherwise

get_all_bw_counters(instances)¶

Return bandwidth usage counters for each interface on each: running VM.

Parameters:	instances – nova.objects.instance.InstanceList

get_all_volume_usage(context, compute_host_bdms)¶: Return usage info for volumes attached to vms on a given host.-

get_available_nodes(refresh=False)¶

Returns nodenames of all nodes managed by the compute service.

This method is for multi compute-nodes support. If a driver supports multi compute-nodes, this method returns a list of nodenames managed by the service. Otherwise, this method should return [hypervisor_hostname].

get_available_resource(nodename)¶

Retrieve resource information.

This method is called when nova-compute launches, and as part of a periodic task that records the results in the DB.

Parameters:	nodename – node which the caller want to get resources from a driver that manages only one node can safely ignore this
Returns:	Dictionary describing resources

get_console_output(context, instance)¶

Get console output for an instance

Parameters:	context – security context instance – nova.objects.instance.Instance

get_console_pool_info(console_type)¶

get_device_name_for_instance(instance, bdms, block_device_obj)¶

Get the next device name based on the block device mapping.

Parameters:	instance – nova.objects.instance.Instance that volume is requesting a device name bdms – a nova.objects.BlockDeviceMappingList for the instance block_device_obj – A nova.objects.BlockDeviceMapping instance with all info about the requested block device. device_name does not need to be set, and should be decided by the driver implementation if not set.
Returns:	The chosen device name.

get_diagnostics(instance)¶

Return data about VM diagnostics.

Parameters:	instance – nova.objects.instance.Instance

get_host_cpu_stats()¶

Get the currently known host CPU stats.

Returns:

a dict containing the CPU stat info, eg:

{‘kernel’: kern,

‘idle’: idle,

‘user’: user,

‘iowait’: wait,

‘frequency’: freq},

where kern and user indicate the cumulative CPU time (nanoseconds) spent by kernel and user processes respectively, idle indicates the cumulative idle CPU time (nanoseconds), wait indicates the cumulative I/O wait CPU time (nanoseconds), since the host is booting up; freq indicates the current CPU frequency (MHz). All values are long integers.

get_host_ip_addr()¶: Retrieves the IP address of the dom0

get_host_uptime()¶: Returns the result of calling “uptime” on the target host.

get_info(instance)¶

Get the current status of an instance, by name (not ID!)

Parameters:	instance – nova.objects.instance.Instance object

Returns a InstanceInfo object

get_instance_diagnostics(instance)¶

Return data about VM diagnostics.

Parameters:	instance – nova.objects.instance.Instance

get_instance_disk_info(instance, block_device_info=None)¶

Retrieve information about actual disk sizes of an instance.

Parameters:

instance – nova.objects.Instance
block_device_info – Optional; Can be used to filter out devices which are actually volumes.

Returns:

json strings with below format:

"[{'path':'disk',
   'type':'raw',
   'virt_disk_size':'10737418240',
   'backing_file':'backing_file',
   'disk_size':'83886080'
   'over_committed_disk_size':'10737418240'},
   ...]"

get_mks_console(context, instance)¶

Get connection info for a MKS console.

Parameters:	context – security context instance – nova.objects.instance.Instance

:returns an instance of console.type.ConsoleMKS

get_num_instances()¶

Return the total number of virtual machines.

Return the number of virtual machines that the hypervisor knows about.

Note

This implementation works for all drivers, but it is not particularly efficient. Maintainers of the virt drivers are encouraged to override this method with something more efficient.

get_per_instance_usage()¶

Get information about instance resource usage.

Returns:	dict of nova uuid => dict of usage info

get_rdp_console(context, instance)¶

Get connection info for a rdp console.

Parameters:	context – security context instance – nova.objects.instance.Instance

:returns an instance of console.type.ConsoleRDP

get_serial_console(context, instance)¶

Get connection info for a serial console.

Parameters:	context – security context instance – nova.objects.instance.Instance

:returns an instance of console.type.ConsoleSerial

get_spice_console(context, instance)¶

Get connection info for a spice console.

Parameters:	context – security context instance – nova.objects.instance.Instance

:returns an instance of console.type.ConsoleSpice

get_vnc_console(context, instance)¶

Get connection info for a vnc console.

Parameters:	context – security context instance – nova.objects.instance.Instance

:returns an instance of console.type.ConsoleVNC

get_volume_connector(instance)¶

Get connector information for the instance for attaching to volumes.

Connector information is a dictionary representing the ip of the machine that will be making the connection, the name of the iscsi initiator and the hostname of the machine as follows:

{
    'ip': ip,
    'initiator': initiator,
    'host': hostname
}

host_maintenance_mode(host, mode)¶: Start/Stop host maintenance window. On start, it triggers guest VMs evacuation.

host_power_action(action)¶: Reboots, shuts down or powers up the host.

init_host(host)¶: Initialize anything that is necessary for the driver to function, including catching up with currently running VM’s on the given host.

inject_file(instance, b64_path, b64_contents)¶

Writes a file on the specified instance.

The first parameter is an instance of nova.compute.service.Instance, and so the instance is being specified as instance.name. The second parameter is the base64-encoded path to which the file is to be written on the instance; the third is the contents of the file, also base64-encoded.

NOTE(russellb) This method is deprecated and will be removed once it can be removed from nova.compute.manager.

inject_network_info(instance, nw_info)¶: inject network info for specified instance.

inject_nmi(instance)¶

Inject an NMI to the specified instance.

Parameters:	instance – nova objects.instance.Instance

instance_exists(instance)¶

Checks existence of an instance on the host.

Parameters:	instance – The instance to lookup

Returns True if an instance with the supplied ID exists on the host, False otherwise.

Note

This implementation works for all drivers, but it is not particularly efficient. Maintainers of the virt drivers are encouraged to override this method with something more efficient.

instance_on_disk(instance)¶

Checks access of instance files on the host.

Parameters:	instance – nova.objects.instance.Instance to lookup

Returns True if files of an instance with the supplied ID accessible on the host, False otherwise.

Note

Used in rebuild for HA implementation and required for validation of access to instance shared disk files

is_supported_fs_format(fs_type)¶

Check whether the file format is supported by this driver

Parameters:	fs_type – the file system type to be checked, the validate values are defined at disk API module.

list_instance_uuids()¶: Return the UUIDS of all the instances known to the virtualization layer, as a list.

list_instances()¶: Return the names of all the instances known to the virtualization layer, as a list.

live_migration(context, instance, dest, post_method, recover_method, block_migration=False, migrate_data=None)¶

Live migration of an instance to another host.

Parameters:

context – security context
instance – nova.db.sqlalchemy.models.Instance object instance object that is migrated.
dest – destination host
post_method – post operation method. expected nova.compute.manager._post_live_migration.
recover_method – recovery method when any exception occurs. expected nova.compute.manager._rollback_live_migration.
block_migration – if true, migrate VM disk.
migrate_data – implementation specific params.

macs_for_instance(instance)¶

What MAC addresses must this instance have?

Some hypervisors (such as bare metal) cannot do freeform virtualisation of MAC addresses. This method allows drivers to return a set of MAC addresses that the instance is to have. allocate_for_instance will take this into consideration when provisioning networking for the instance.

Mapping of MAC addresses to actual networks (or permitting them to be freeform) is up to the network implementation layer. For instance, with openflow switches, fixed MAC addresses can still be virtualised onto any L2 domain, with arbitrary VLANs etc, but regular switches require pre-configured MAC->network mappings that will match the actual configuration.

Most hypervisors can use the default implementation which returns None. Hypervisors with MAC limits should return a set of MAC addresses, which will be supplied to the allocate_for_instance call by the compute manager, and it is up to that call to ensure that all assigned network details are compatible with the set of MAC addresses.

This is called during spawn_instance by the compute manager.

Returns:	None, or a set of MAC ids (e.g. set([‘12:34:56:78:90:ab’])). None means ‘no constraints’, a set means ‘these and only these MAC addresses’.

manage_image_cache(context, all_instances)¶

Manage the driver’s local image cache.

Some drivers chose to cache images for instances on disk. This method is an opportunity to do management of that cache which isn’t directly related to other calls into the driver. The prime example is to clean the cache and remove images which are no longer of interest.

Parameters:	all_instances – nova.objects.instance.InstanceList

migrate_disk_and_power_off(context, instance, dest, flavor, network_info, block_device_info=None, timeout=0, retry_interval=0)¶

Transfers the disk of a running instance in multiple phases, turning off the instance before the end.

Parameters:	instance – nova.objects.instance.Instance timeout – time to wait for GuestOS to shutdown retry_interval – How often to signal guest while waiting for it to shutdown

need_legacy_block_device_info¶

Tell the caller if the driver requires legacy block device info.

Tell the caller whether we expect the legacy format of block device info to be passed in to methods that expect it.

node_is_available(nodename)¶: Return whether this compute service manages a particular node.

pause(instance)¶

Pause the specified instance.

Parameters:	instance – nova.objects.instance.Instance

plug_vifs(instance, network_info)¶

Plug VIFs into networks.

Parameters:	instance – nova.objects.instance.Instance

poll_rebooting_instances(timeout, instances)¶

Poll for rebooting instances

Parameters:	timeout – the currently configured timeout for considering rebooting instances to be stuck instances – instances that have been in rebooting state longer than the configured timeout

post_interrupted_snapshot_cleanup(context, instance)¶

Cleans up any resources left after an interrupted snapshot.

Parameters:	context – security context instance – nova.objects.instance.Instance

post_live_migration(context, instance, block_device_info, migrate_data=None)¶

Post operation of live migration at source host.

Block_device_info:
Parameters:	context – security context migrate_data – if not None, it is a dict which has data
Instance:	instance object that was migrated
	instance block device information

post_live_migration_at_destination(context, instance, network_info, block_migration=False, block_device_info=None)¶

Post operation of live migration at destination host.

Parameters:	context – security context instance – instance object that is migrated network_info – instance network information block_migration – if true, post operation of block_migration.

post_live_migration_at_source(context, instance, network_info)¶

Unplug VIFs from networks at source.

Parameters:	context – security context instance – instance object reference network_info – instance network information

power_off(instance, timeout=0, retry_interval=0)¶

Power off the specified instance.

Parameters:	instance – nova.objects.instance.Instance timeout – time to wait for GuestOS to shutdown retry_interval – How often to signal guest while waiting for it to shutdown

power_on(context, instance, network_info, block_device_info=None)¶

Power on the specified instance.

Parameters:	instance – nova.objects.instance.Instance

pre_live_migration(context, instance, block_device_info, network_info, disk_info, migrate_data=None)¶

Prepare an instance for live migration

Parameters:	context – security context instance – nova.objects.instance.Instance object block_device_info – instance block device information network_info – instance network information disk_info – instance disk information migrate_data – implementation specific data dict.

quiesce(context, instance, image_meta)¶

Quiesce the specified instance to prepare for snapshots.

If the specified instance doesn’t support quiescing, InstanceQuiesceNotSupported is raised. When it fails to quiesce by other errors (e.g. agent timeout), NovaException is raised.

Parameters:	context – request context instance – nova.objects.instance.Instance to be quiesced image_meta – image object returned by nova.image.glance that defines the image from which this instance was created

reboot(context, instance, network_info, reboot_type, block_device_info=None, bad_volumes_callback=None)¶

Reboot the specified instance.

After this is called successfully, the instance’s state goes back to power_state.RUNNING. The virtualization platform should ensure that the reboot action has completed successfully even in cases in which the underlying domain/vm is paused or halted/stopped.

Parameters:	instance – nova.objects.instance.Instance network_info – `get_instance_nw_info()` reboot_type – Either a HARD or SOFT reboot block_device_info – Info pertaining to attached volumes bad_volumes_callback – Function to handle any bad volumes encountered

rebuild(context, instance, image_meta, injected_files, admin_password, bdms, detach_block_devices, attach_block_devices, network_info=None, recreate=False, block_device_info=None, preserve_ephemeral=False)¶

Destroy and re-make this instance.

A ‘rebuild’ effectively purges all existing data from the system and remakes the VM with given ‘metadata’ and ‘personalities’.

This base class method shuts down the VM, detaches all block devices, then spins up the new VM afterwards. It may be overridden by hypervisors that need to - e.g. for optimisations, or when the ‘VM’ is actually proxied and needs to be held across the shutdown + spin up steps.

Parameters:

context – security context
instance – nova.objects.instance.Instance This function should use the data there to guide the creation of the new instance.
image_meta – image object returned by nova.image.glance that defines the image from which to boot this instance
injected_files – User files to inject into instance.
admin_password – Administrator password to set in instance.
bdms – block-device-mappings to use for rebuild
detach_block_devices – function to detach block devices. See nova.compute.manager.ComputeManager:_rebuild_default_impl for usage.
attach_block_devices – function to attach block devices. See nova.compute.manager.ComputeManager:_rebuild_default_impl for usage.
network_info – get_instance_nw_info()
recreate – True if the instance is being recreated on a new hypervisor - all the cleanup of old state is skipped.
block_device_info – Information about block devices to be attached to the instance.
preserve_ephemeral – True if the default ephemeral storage partition must be preserved on rebuild

refresh_instance_security_rules(instance)¶

Refresh security group rules

Gets called when an instance gets added to or removed from the security group the instance is a member of or if the group gains or loses a rule.

refresh_provider_fw_rules()¶

This triggers a firewall update based on database changes.

When this is called, rules have either been added or removed from the datastore. You can retrieve rules with nova.db.provider_fw_rule_get_all().

Provider rules take precedence over security group rules. If an IP would be allowed by a security group ingress rule, but blocked by a provider rule, then packets from the IP are dropped. This includes intra-project traffic in the case of the allow_project_net_traffic flag for the libvirt-derived classes.

refresh_security_group_members(security_group_id)¶

This method is called when a security group is added to an instance.

This message is sent to the virtualization drivers on hosts that are running an instance that belongs to a security group that has a rule that references the security group identified by security_group_id. It is the responsibility of this method to make sure any rules that authorize traffic flow with members of the security group are updated and any new members can communicate, and any removed members cannot.

Scenario:

we are running on host ‘H0’ and we have an instance ‘i-0’.
instance ‘i-0’ is a member of security group ‘speaks-b’
group ‘speaks-b’ has an ingress rule that authorizes group ‘b’
another host ‘H1’ runs an instance ‘i-1’
instance ‘i-1’ is a member of security group ‘b’

When ‘i-1’ launches or terminates we will receive the message to update members of group ‘b’, at which time we will make any changes needed to the rules for instance ‘i-0’ to allow or deny traffic coming from ‘i-1’, depending on if it is being added or removed from the group.

In this scenario, ‘i-1’ could just as easily have been running on our host ‘H0’ and this method would still have been called. The point was that this method isn’t called on the host where instances of that group are running (as is the case with refresh_security_group_rules()) but is called where references are made to authorizing those instances.

An error should be raised if the operation cannot complete.

refresh_security_group_rules(security_group_id)¶

This method is called after a change to security groups.

All security groups and their associated rules live in the datastore, and calling this method should apply the updated rules to instances running the specified security group.

An error should be raised if the operation cannot complete.

register_event_listener(callback)¶

Register a callback to receive events.

Register a callback to receive asynchronous event notifications from hypervisors. The callback will be invoked with a single parameter, which will be an instance of the nova.virt.event.Event class.

remove_from_aggregate(context, aggregate, host, **kwargs)¶: Remove a compute host from an aggregate.

rescue(context, instance, network_info, image_meta, rescue_password)¶

Rescue the specified instance.

Parameters:	instance – nova.objects.instance.Instance

reset_network(instance)¶: reset networking for specified instance.

restore(instance)¶

Restore the specified instance.

Parameters:	instance – nova.objects.instance.Instance

resume(context, instance, network_info, block_device_info=None)¶

resume the specified instance.

Parameters:	context – the context for the resume instance – nova.objects.instance.Instance being resumed network_info – `get_instance_nw_info()` block_device_info – instance volume block device info

resume_state_on_host_boot(context, instance, network_info, block_device_info=None)¶

resume guest state when a host is booted.

Parameters:	instance – nova.objects.instance.Instance

rollback_live_migration_at_destination(context, instance, network_info, block_device_info, destroy_disks=True, migrate_data=None)¶

Clean up destination node after a failed live migration.

Parameters:	context – security context instance – instance object that was being migrated network_info – instance network information block_device_info – instance block device information destroy_disks – if true, destroy disks at destination during cleanup migrate_data – implementation specific params

set_admin_password(instance, new_pass)¶

Set the root password on the specified instance.

Parameters:	instance – nova.objects.instance.Instance new_pass – the new password

set_bootable(instance, is_bootable)¶

Set the ability to power on/off an instance.

Parameters:	instance – nova.objects.instance.Instance

set_host_enabled(enabled)¶: Sets the specified host’s ability to accept new instances.

snapshot(context, instance, image_id, update_task_state)¶

Snapshots the specified instance.

Parameters:	context – security context instance – nova.objects.instance.Instance image_id – Reference to a pre-created image that will hold the snapshot.

soft_delete(instance)¶

Soft delete the specified instance.

Parameters:	instance – nova.objects.instance.Instance

spawn(context, instance, image_meta, injected_files, admin_password, network_info=None, block_device_info=None)¶

Create a new instance/VM/domain on the virtualization platform.

Once this successfully completes, the instance should be running (power_state.RUNNING).

If this fails, any partial instance should be completely cleaned up, and the virtualization platform should be in the state that it was before this call began.

Parameters:

context – security context
instance – nova.objects.instance.Instance This function should use the data there to guide the creation of the new instance.
image_meta – image object returned by nova.image.glance that defines the image from which to boot this instance
injected_files – User files to inject into instance.
admin_password – Administrator password to set in instance.
network_info – get_instance_nw_info()
block_device_info – Information about block devices to be attached to the instance.

suspend(context, instance)¶

suspend the specified instance.

Parameters:	context – the context for the suspend instance – nova.objects.instance.Instance

swap_volume(old_connection_info, new_connection_info, instance, mountpoint, resize_to)¶

Replace the disk attached to the instance.

Parameters:	instance – nova.objects.instance.Instance resize_to – This parameter is used to indicate the new volume size when the new volume lager than old volume. And the units is Gigabyte.

undo_aggregate_operation(context, op, aggregate, host, set_error=True)¶: Undo for Resource Pools.

unfilter_instance(instance, network_info)¶: Stop filtering instance.

unpause(instance)¶

Unpause paused VM instance.

Parameters:	instance – nova.objects.instance.Instance

unplug_vifs(instance, network_info)¶

Unplug VIFs from networks.

Parameters:	instance – nova.objects.instance.Instance

unquiesce(context, instance, image_meta)¶

Unquiesce the specified instance after snapshots.

If the specified instance doesn’t support quiescing, InstanceQuiesceNotSupported is raised. When it fails to quiesce by other errors (e.g. agent timeout), NovaException is raised.

Parameters:	context – request context instance – nova.objects.instance.Instance to be unquiesced image_meta – image object returned by nova.image.glance that defines the image from which this instance was created

unrescue(instance, network_info)¶

Unrescue the specified instance.

Parameters:	instance – nova.objects.instance.Instance

volume_snapshot_create(context, instance, volume_id, create_info)¶

Snapshots volumes attached to a specified instance.

Parameters:

context – request context
instance – nova.objects.instance.Instance that has the volume attached
volume_id – Volume to be snapshotted
create_info – The data needed for nova to be able to attach to the volume. This is the same data format returned by Cinder’s initialize_connection() API call. In the case of doing a snapshot, it is the image file Cinder expects to be used as the active disk after the snapshot operation has completed. There may be other data included as well that is needed for creating the snapshot.

volume_snapshot_delete(context, instance, volume_id, snapshot_id, delete_info)¶

Snapshots volumes attached to a specified instance.

Parameters:

context – request context
instance – nova.objects.instance.Instance that has the volume attached
volume_id – Attached volume associated with the snapshot
snapshot_id – The snapshot to delete.
delete_info – Volume backend technology specific data needed to be able to complete the snapshot. For example, in the case of qcow2 backed snapshots, this would include the file being merged, and the file being merged into (if appropriate).

block_device_info_get_ephemerals(block_device_info)¶

block_device_info_get_mapping(block_device_info)¶

block_device_info_get_root(block_device_info)¶

block_device_info_get_swap(block_device_info)¶

compute_driver_matches(match)¶

driver_dict_from_config(named_driver_config, *args, **kwargs)¶

get_block_device_info(instance, block_device_mapping)¶

Converts block device mappings for an instance to driver format.

Virt drivers expect block device mapping to be presented in the format of a dict containing the following keys:

root_device_name: device name of the root disk
ephemerals: a (potentially empty) list of DriverEphemeralBlockDevice

instances
swap: An instance of DriverSwapBlockDevice or None
block_device_mapping: a (potentially empty) list of

DriverVolumeBlockDevice or any of it’s more specialized subclasses.

load_compute_driver(virtapi, compute_driver=None)¶

Load a compute driver module.

Load the compute driver module specified by the compute_driver configuration option or, if supplied, the driver name supplied as an argument.

Compute drivers constructors take a VirtAPI object as their first object and this must be supplied.

Parameters:	virtapi – a VirtAPI instance compute_driver – a compute driver name to override the config opt
Returns:	a ComputeDriver instance

swap_is_usable(swap)¶

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The `nova.virt.driver` Module¶