The nova.virt.libvirt.utils Module

chown(path, owner)

Change ownership of file or directory

Parameters:

• path – File or directory whose ownership to change
• owner – Desired new owner (given as uid or username)

copy_image(src, dest)

Copy a disk image

Parameters:

• src – Source image
• dest – Destination path

create_cow_image(backing_file, path)

Create COW image

Creates a COW image with the given backing file

Parameters:

• backing_file – Existing image on which to base the COW image
• path – Desired location of the COW image

create_image(disk_format, path, size)

Create a disk image

Parameters:

• disk_format – Disk image format (as known by qemu-img)
• path – Desired location of the disk image
• size – Desired size of disk image. May be given as an int or a string. If given as an int, it will be interpreted as bytes. If it’s a string, it should consist of a number with an optional suffix (‘K’ for Kibibytes, M for Mebibytes, ‘G’ for Gibibytes, ‘T’ for Tebibytes). If no suffix is given, it will be interpreted as bytes.

create_snapshot(disk_path, snapshot_name)

Create a snapshot in a disk image

Parameters:

• disk_path – Path to disk image
• snapshot_name – Name of snapshot in disk image

delete_snapshot(disk_path, snapshot_name)

Create a snapshot in a disk image

Parameters:

• disk_path – Path to disk image
• snapshot_name – Name of snapshot in disk image

ensure_tree(path)

Create a directory (and any ancestor directories required)

Parameters:path – Directory to create

execute(*args, **kwargs)

extract_snapshot(disk_path, source_fmt, snapshot_name, out_path, dest_fmt)

Extract a named snapshot from a disk image

Parameters:

• disk_path – Path to disk image
• snapshot_name – Name of snapshot in disk image
• out_path – Desired path of extracted snapshot

fetch_image(context, target, image_id, user_id, project_id)

Grab image

file_delete(path)

Delete (unlink) file

Note: The reason this is kept in a separate module is to easily

be able to provide a stub module that doesn’t alter system state at all (for unit tests)

file_open(*args, **kwargs)

Open file

see built-in file() documentation for more details

Note: The reason this is kept in a separate module is to easily

be able to provide a stub module that doesn’t alter system state at all (for unit tests)

get_disk_backing_file(path)

Get the backing file of a disk image

Parameters:path – Path to the disk image Returns:a path to the image’s backing store

get_disk_size(path)

Get the (virtual) size of a disk image

Parameters:path – Path to the disk image Returns:Size (in bytes) of the given disk image as it would be seen by a virtual machine.

get_fs_info(path)

Get free/used/total space info for a filesystem

Parameters:path – Any dirent on the filesystem Returns:A dict containing:

free:How much space is free (in bytes) used:How much space is used (in bytes) total:How big the filesystem is (in bytes)

get_iscsi_initiator()

Get iscsi initiator name for this machine

get_open_port(start_port, end_port)

Find an available port

Parameters:

• start_port – Start of acceptable port range
• end_port – End of acceptable port range

load_file(path)

Read contents of file

Parameters:path – File to read

mkfs(fs, path, label=None)

Format a file or block device

Parameters:

• fs – Filesystem type (examples include ‘swap’, ‘ext3’, ‘ext4’ ‘btrfs’, etc.)
• path – Path to file or block device to format
• label – Volume label to use

write_to_file(path, contents, umask=None)

Write the given contents to a file

Parameters:

• path – Destination file
• contents – Desired contents of the file
• umask – Umask to set when creating this file (will be reset)