Canonical released Ubuntu Core 18, based on Ubuntu 18.04 LTS, bringing 10-year support to the embedded Linux platform. Other enhancements include a reduced attack surface and easier porting of Ubuntu apps.

Canonical’s stripped-down, container-like Ubuntu Core version of Ubuntu for embedded IoT has reached version 18. The most significant benefit is that the distro is based on Ubuntu 18.04 LTS (Bionic Beaver), which was released in early 2018. The release’s long-term support (LTS) status means Canonical promises to support it for 10 years, improving the chance of warding off malware attacks throughout the product lifespan.

LimeNET Micro

Ubuntu Core, which runs on a variety of devices including Lime SDR boards such as the LimeNET Micro board, is already notable for being one of the more secure embedded Linux distros around. Its “snap” apps are containerized, and it offers transactional updates, among other security features.

In addition to the LTS status, the new release should be even more secure because the already minimalist distro has the smallest footprint yet, fitting into 260MB, according to the ZDNet story that alerted us to the release. According to Canonical’s announcement: “The attack surface of Ubuntu Core has been minimized, with very few packages installed in the base OS, reducing the size and frequency of security updates and providing more storage for applications and data.”

 
Easier porting of Ubuntu and Snapcraft apps

The other major enhancement in version 18 is the introduction of a new class of app-centric things. This allows Ubuntu Core developers to more easily inherit apps from the broader Ubuntu and Snapcraft ecosystems “or build unique and exclusive applications that are specific to a brand or model,” says Canonical. In addition: “Specific apps can be required, or optional, per model. Manufacturers get complete control over the versions and updates relevant to their own devices.”

Snapcraft is the name for both the yaml-based package build tool for the snap applications that drive Ubuntu Core, as well as the universal app store for snaps. In 2016 Canonical proposed to share the snap format and snapcraft tool with the Linux community with the hopes of making it a universal package management standard.

The Linux distro community has yet to fully embrace the concept, but the Snapcraft site now lists snap apps developed by Amazon, Microsoft, Google, Mozilla, and Spotify in addition to Canonical’s own snaps. Since Ubuntu Core has an app store mechanism already built in, developers can also build their own snap app stores, as Lime has done with its SDR systems.

The “immutable, digitally signed” snaps are securely confined, read-only, tamper-proof application images that are digitally signed to ensure integrity. Update controls allow app publishers and device vendors to validate updates across the ecosystem before they are applied. Snaps are also transactional, so failures are automatically rolled back. Because they’re containerized in a sandbox, one corrupt snap won’t contaminate others.

The snaps that run on Ubuntu Core “work just as well on Ubuntu Server, Desktop and cloud images,” says Canonical. “One platform, one format, and one process mean that the developer workstation, build farm, cloud and servers can all participate in the software design and development lifecycle. Running those snaps on Ubuntu Core provides a higher level of security than any other version of Ubuntu because the entire platform is made of strictly confined snaps.”

Rigado Vesta IoT Gateway

Ubuntu Core has steadily gained customers over the years, including Dell, Lime Microsystems, Intel, Qualcomm, Samsung, NXP, and Rigado. Because it’s primarily designed for the still relatively small number of embedded devices that offer a range of different apps, it is not as widely used as desktop Ubuntu in the embedded community, but it has shown steady progress. It has even been honored with forked versions for hacker board projects, such as FriendlyElec’s FriendlyCore, which runs on many of its NanoPi SBCs.

 
Further information

Ubuntu Core 18 is available for free download. More information may be found at Canonical’s Ubuntu Core 18 announcement and Ubuntu Core product page.