imgutil(1) - Work with confluent OS cloning and diskless images
  1. imgutil(1)
  3. imgutil(1)

NAME

imgutil - Work with confluent OS cloning and diskless images

SYNOPSIS

imgutil build [options] scratchdir
imgutil exec [options] scratchdir [cmd...]
imgutil unpack profilename scratchdir
imgutil pack [options] scratchdir profilename
imgutil capture node profilename

DESCRIPTION

imgutil is a utility for creating, managing, and deploying OS images for diskless boot and system cloning in a Confluent environment. It supports building images from scratch, capturing images from running systems, and packing/unpacking diskless profiles.

COMMANDS

build
Build a new diskless image from scratch in the specified scratch directory.
exec
Start the specified scratch directory as a container and optionally run a command inside it.
unpack
Unpack a diskless image profile to a scratch directory for modification.
pack
Pack a scratch directory into a diskless profile that can be deployed.
capture
Capture an image for cloning from a running system.

BUILD OPTIONS

-r, --addrepos repository
Repositories to add in addition to the main source. May be specified multiple times.
-p, --packagelist file
Filename of package list to replace default pkglist.
-a, --addpackagelist file
A list of additional packages to include. May be specified multiple times.
-s, --source directory
Directory to pull installation from, typically a subdirectory of /var/lib/confluent/distributions. By default, the repositories for the build system are used. For Ubuntu, this is not supported; the build system repositories are always used.
-y, --non-interactive
Avoid prompting for confirmation.
-v, --volume mount
Directory to make available in the build environment. -v / will cause it to be mounted in image as /run/external/. -v /:/run/root will override the target to be /run/root. Something like /var/lib/repository:- will cause it to mount to the identical path inside the image. May be specified multiple times.
scratchdir
Directory to build new diskless root in.

EXEC OPTIONS

-v, --volume mount
Directory to make available in the build environment. -v / will cause it to be mounted in image as /run/external/. -v /:/run/root will override the target to be /run/root. May be specified multiple times.
scratchdir
Directory of an unpacked diskless root.
cmd
Optional command to run (defaults to a shell).

UNPACK OPTIONS

profilename
The diskless OS profile to unpack.
scratchdir
Directory to extract diskless root to.

PACK OPTIONS

-b, --baseprofile profile
Profile to copy extra info from. For example, to make a new version of an existing profile, reference the previous one as baseprofile.
-u, --unencrypted
Pack an unencrypted image rather than encrypting.
scratchdir
Directory containing diskless root.
profilename
The desired diskless OS profile name to pack the root into.

CAPTURE OPTIONS

node
Node to capture image from.
profilename
Profile name for captured image.

EXAMPLES

Build a diskless image from a distribution:

imgutil build -s  alma-9.6-x86_64 /tmp/myimage

Execute a shell in an unpacked image:

imgutil exec /tmp/myimage

Execute a specific command in an image:

imgutil exec /tmp/myimage /bin/rpm -qa

Unpack an existing profile for modification:

imgutil unpack myprofile /tmp/myimage

Pack a modified image into a new profile:

imgutil pack /tmp/myimage myprofile-v2

Capture an image from a running node:

imgutil capture node01 production-image

FILES

/var/lib/confluent/public/os/
Default location for OS profiles.
/var/lib/confluent/private/os/
Location for encrypted image keys and private data.
/var/lib/confluent/distributions/
Default location for installation sources.

SEE ALSO

osdeploy(8)

AUTHOR

Written for the Confluent project.

  2. December 2025
  3. imgutil(1)