COT.add_disk module

Module for adding disks to VMs.

Functions

add_disk_worker	Worker function for actually adding the disk.
confirm_elements	Get user confirmation of any risky or unusual operations.
guess_controller_type	If a controller type wasn’t specified, try to guess from context.
guess_disk_type_from_extension	Guess the disk type (harddisk/cdrom) from the disk file name.
search_for_elements	Search for a unique set of objects based on the given criteria.
validate_elements	Validate any existing file, disk, controller item, and disk item.
validate_controller_address	Check validity of the given address string for the given controller.

Classes

COTAddDisk

Add or replace a disk in a virtual machine.

class COTAddDisk(ui)

Bases: COT.submodule.COTSubmodule

Add or replace a disk in a virtual machine.

Inherited attributes: UI, package, output

Attributes: disk_image, type, file_id, controller, subtype, address, diskname, description

create_subparser()

Create ‘add-disk’ CLI subparser.

ready_to_run()

Check whether the module is ready to run().

Returns:(True, ready_message) or (False, reason_why_not)

run()

Do the actual work of this submodule.

Raises:InvalidInputError – if ready_to_run() reports False

address

Disk device address on controller (1:0, etc.).

Raises:InvalidInputError, see validate_controller_address()

controller

Disk controller type (ide, scsi).

Raises:InvalidInputError, see validate_controller_address()

description = None

Description of the disk.

disk_image

Path to disk image file to add to the VM.

Raises:InvalidInputError if the file does not exist.

disk_type = None

Disk type (‘harddisk’ or ‘cdrom’).

diskname = None

Name string for the disk.

file_id = None

File identifier to map disk to file.

subtype = None

Controller subtype, such as “virtio”.

add_disk_worker(vm, ui, disk_image, disk_type=None, file_id=None, controller=None, subtype=None, address=None, diskname=None, description=None)

Worker function for actually adding the disk.

All parameters except vm, ui, and disk_image are optional and will be automatically determined by COT if unspecified.

Parameters:

• vm (OVF or other VMDescription subclass) – The virtual machine being edited.
• ui (instance of UI or subclass.) – User interface in effect.
• disk_image (str) – path to disk image to add to the VM.
• disk_type (str) – Disk type: 'cdrom' or 'harddisk'. If not specified, will be derived automatically from the disk_image file name extension.
• file_id (str) – Identifier of the disk file in the VM. If not specified, the VM will automatically derive an appropriate value.
• controller (str) – Disk controller type: 'ide' or 'scsi'. If not specified, will be derived from the type and the platform of the given vm.
• subtype (str) – Controller subtype (‘virtio’, ‘lsilogic’, etc.)
• address (str) – Disk device address on its controller (such as '1:0'). If this matches an existing disk device, that device will be overwritten. If not specified, the first available address not already occupied by an existing device will be selected.
• diskname (str) – Name for disk device
• description (str) – Description of disk device

confirm_elements(vm, ui, file_obj, disk_image, disk_obj, disk_item, disk_type, controller, ctrl_item, subtype)

Get user confirmation of any risky or unusual operations.

guess_controller_type(vm, ctrl_item, disk_type)

If a controller type wasn’t specified, try to guess from context.

guess_disk_type_from_extension(disk_file)

Guess the disk type (harddisk/cdrom) from the disk file name.

search_for_elements(vm, disk_file, file_id, controller, address)

Search for a unique set of objects based on the given criteria.

A disk is defined by up to four different sections in the OVF:

File (references the actual disk image file) Disk (references the File, only used for HD not CD-ROM) Item (defines the SCSI/IDE controller) Item (defines the disk drive, links to controller and File or Disk)

For each of these four sections, we need to know whether to add a new one or overwrite an existing one. Depending on the user arguments, we can do this by as many as three different approaches:

1. Check whether the DISK_IMAGE file name matches an existing File in the OVF (and from there, find the associated Disk and Items)
2. Check whether the file-id matches an existing File and/or Disk in the OVF (and from there, find the associated Items)
3. Check whether controller type and/or device address match existing Items in the OVF (and from there, find the associated Disk and/or File)

Where it gets extra fun is if the user has specified more than one of the above arguments - in which case we need to make sure that all relevant approaches agree on what sections we’re talking about...

Raises:ValueMismatchError – if the criteria select a non-unique set. Returns:(file_object, disk_object, controller_item, disk_item)

validate_controller_address(controller, address)

Check validity of the given address string for the given controller.

Helper method for the controller/address setters.

Parameters:

• controller (str) – 'ide' or 'scsi'
• address (str) – A string like ‘0:0’ or ‘2:10’

Raises:

InvalidInputError if the address/controller combo is invalid.

validate_elements(vm, file_obj, disk_obj, disk_item, ctrl_item, file_id, ctrl_type)

Validate any existing file, disk, controller item, and disk item.

Raises:ValueMismatchError – if the search criteria select a non-unique set.