Running supported, enterprise-grade workloads in containers and virtual machines is now even easier. 

With the latest LXD release, Ubuntu Pro supports auto-attachment for LXD guest instances, offering organizations a seamless way to extend Ubuntu Pro benefits across their infrastructure.

Until now, enabling Ubuntu Pro inside an LXD guest required a manual step: running pro attach within each instance using a token, even if the host was already Pro-attached. That approach worked but introduced friction, particularly for large-scale deployments. With the new auto-attach feature, your Pro-attached host can automatically extend Ubuntu Pro privileges to its LXD containers and virtual machines. This isn’t just a quality-of-life improvement; it’s a major step for organizations that want to improve operational efficiency and security. 

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class="wp-block-heading">Why does this matter?

Ubuntu Pro comes with a host of useful features, including expanded security maintenance, kernel livepatching, compliance (including FIPS), hardening, and security coverage for thousands of supported open source packages. By bringing auto-attach support to LXD guests, Canonical ensures these benefits are extended effortlessly to containerized and virtual workloads. 

Whether you’re running a single-node developer workstation or a MicroCloud deployment in your data center, your guests can now inherit Ubuntu Pro benefits at launch, with no manual token gymnastics required. The subscription is per physical server with unlimited VMs, making it very compelling for organizations operating in regulated environments or those looking to harden their Linux estates at a great value for money. 

How it works

To enable auto-attachment, the LXD host must already be attached to a Pro subscription (via token or auto-attach in public cloud environments). Then, use the new  lxd_guest_attach setting in the Ubuntu Pro client to control guest behavior: 

pro config set lxd_guest_attach={on,available,off}

The lxd_guest_attach setting accepts three values:

• on: All LXD guests will auto-attach Pro at launch
• available: Guests can auto-attach, but it won’t happen by default
• off: Auto-attach is disabled

The setting is safely managed: attempts to change it on a Pro-detached host will fail, and it resets to off when detaching. 

Once enabled, any new LXD instance based on a supported Ubuntu image will attach to the same Pro contract as its host. These attachments remain independent but follow the same contract, inheriting updates made upstream. 

Still want manual control? No problem.

Manual pro attach using a token remains fully supported. There are no plans to deprecate that path — this new functionality simply adds an easier, faster alternative that’s effortless to scale. 

Pro auto-attachment can be configured at the profile level or for each guest:

lxc config set ubuntu_pro.guest_attach={on,available,off}

This configuration overrides the host setting only if the host setting is either on or available. If the host setting is configured to off, the guests cannot override it.

A foundation for Pro-enabled MicroClouds

Auto-attach speeds up and simplifies Pro-enabled MicroCloud deployment. Instead of managing individual guest licenses, a Pro-attached host becomes the anchor point for unlimited secure guests. This is an attractive option for private cloud environments, edge deployments, multi-tenant hosting, and secure application platforms. 

Canonical is continuing to evolve LXD, MicroCloud, and Ubuntu Pro, strengthening the links between them. As these links grow stronger, it becomes easier for enterprises to ensure their infrastructure is both flexible and highly secure. Pro-attach simplifies the path to building trusted virtualized environments and reflects Canonical’s commitment to making Pro benefits ubiquitous across all environments — from public clouds to bare metal and beyond. 

Get started today

To begin using Ubuntu Pro auto-attach with your LXD guests:

1. Make sure your host is attached to Ubuntu Pro, running the latest version of the Ubuntu Pro client.
2. Configure your host:

pro config set lxd_guest_attach=on

3. Install and initialize the latest version of LXD:

sudo snap install lxd --channel=6/stable

4. Launch your LXD guest instance using a supported Ubuntu image using the CLI

lxc launch ubuntu:24.04 v1

or via the appropriate action in the UI

5. Inside the guest, enjoy automatic access to the full suite of Pro features,.

For organizations seeking to secure their workloads without increasing operational overhead, this is a game-changing enhancement.

Read more about Ubuntu Pro, or the auto-attach feature itself.

Find out more about LXD.