Canonical released its lightweight Ubuntu Core 16, now completely built with snap packages, featuring a smaller footprint and better lifecycle management.
Canonical released version 16 of Ubuntu Core, built entirely from the snap packages that debuted in the lightweight Snappy Ubuntu Core embedded version of Ubuntu Linux announced in Jan. 2015. Now there’s a single all-snaps version of Ubuntu Core that runs on embedded devices as well as the cloud.
Ubuntu Core, which was part of our recent survey of open source IoT OSes, now runs on the Raspberry Pi, Gumstix boards, Erle Robotics drones, Dell Edge Gateways, the Nextcloud Box, LimeSDR, Samsung Artik modules, the Mycroft home hub, Intel’s Joule, and SBCs compliant with Linaro’s 96Boards spec, among other devices. In June, Canonical spun off the Snap transactional mechanism for standalone use with any Linux distribution, thereby offering a cross-platform package management solution for the greater Linux community.
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.
Classic Ubuntu (left) architecture vs. Ubuntu Core 16
(click image to enlarge)
In Ubuntu Core 16, even the kernel and OS are delivered as snaps, so the entire platform is transactionally upgradeable. A universal or device-specific white label snap app store is also baked into the distribution.
When asked for more details on the differences between Ubuntu Core 15 and 16, Canonical supplied the following:
- Ubuntu Core 16 has a smaller footprint in terms of RAM and memory, with a 350MB OS image size.
- Ubuntu Core 16 is built entirely from snaps, including independent kernel snap, OS (rootfs) snap, library snap, and application snaps.
- Snaps are deployed as read-only, immutable, and compressed squashfs blobs on disk.
- Snaps provide improved software lifecycle management control and proof of provenance.
- System/application snap updates “are xdelta diffs delivered over-the-air significantly reducing bandwidth costs.”
- Interfaces are the new primitives that allow snaps to communicate and share resources, extending default security policy allowed for snaps.
- Assertions (digitally signed documents) allow expressing a fact or policy by a particular authority about a particular object in the snap universe, such as, when to update the system.
Canonical’s announcement includes testimonial quotes from Dell, IBM, Intel, Linaro, and OSRF. Stated George Grey, Linaro CEO: “Ubuntu Core 16 will help developers get their products to market quickly using snaps, bringing a new generation of Linux based IoT smart devices to the market.”