How to configure Ubuntu Pro guest attachment

If Ubuntu Pro is enabled on a LXD host, guest instances can be automatically attached to the Pro subscription.

First, the Pro client on the host machine must be configured to allow guest attachment:

pro config set lxd_guest_attach=on

The allowed values are on, off, and available. If unset, this defaults to off.

Note

The Pro client must be updated to the latest version.

You can now launch an Ubuntu instance:

lxc launch ubuntu:24.04 pro-guest

The instance will automatically attach to the Pro subscription at start up.

Pro attachment can take some time. You can check the status using:

lxc exec pro-guest -- pro status

The lxd_guest_attach setting can be overridden by the ubuntu_pro.guest_attach configuration option. For example, if lxd_guest_attach is set to on on the host, to prevent Pro attachment in the guest you can run:

lxc launch ubuntu:24.04 non-pro-guest -c ubuntu_pro.guest_attach=off

The ubuntu_pro.guest_attach configuration key has three options: on, off, and available.

All options for Pro guest attachment are described below.

	on (host)	available (host)	off (host)	unset (host)
on (guest)	auto-attach on start	auto-attach on start	guest attachment disabled	guest attachment disabled
available (guest)	attach on pro auto-attach	attach on pro-auto-attach	guest attachment disabled	guest attachment disabled
off (guest)	guest attachment disabled	guest attachment disabled	guest attachment disabled	guest attachment disabled
unset (guest)	auto-attach on start	attach on pro-auto-attach	guest attachment disabled	guest attachment disabled