Ubuntu is previewing LXD with the 15.05 release. It's far from ready for general use but gives you a taste of things to come. LXD is available both as a standalone application and an Openstack Nova plugin.

LXC developer Stephane Graber has a blog post on the release here. Those who have followed some of our recent posts will know LXD builds on LXC. They key thing is LXD uses unprivileged containers by default, provides a REST api for multi-host management and live migration.

A few interesting things come out of that post. LXD moves away from LXC container OS templates to 'images' available from images.linuxcontainers.org server. You can host your own server. The configuration file for containers has also been moved to a sqlite db, and a lot of configuration options are work in progress.

A lot of LXD features are upstream and its will take some time to become available in other distros beyond Ubuntu so for the time being it remains the best platform to experiment with LXD.

There are a number of issues that are still being ironed out. Handling cgroups and systemd both in the host and containers is one sticky area. Handling cgroups in unprivileged systemd containers is still work in progress. For a fully functional LXD CGManager and LXCFS is going to be required. A lot of these are not well tested outside Ubuntu and need to mature.

LXC will be developed simultaneously with LXD. LXD will provide container management across hosts and things like live migration and use the underlying LXC api to manage local containers.  LXD handles containers a bit differently and while it matures and becomes better documented you can continue to use LXC the old way.

We will shortly post a quick overview of using LXD.