Lean. Agile. Svelte. Lithe. Free.
That's how we roll our operating systems in this modern, bountiful era of broadly deployed virtual machines, densely packed with system containers.
Linux, and more generally free software, is a natural fit in this model where massive scale is the norm. And particularly Ubuntu (with its solid Debian base), is perfectly suited to this brave new world.
Introduced in Ubuntu 8.04 LTS (Hardy) -- November 19, 2007, in fact -- JeOS (pronounced, "juice") was the first of its kind. An absolutely bare minimal variant of the Ubuntu Server, tailored to perfection for virtual machines and appliances. Just enough OS.
Taken aback, I overheard a technical executive at a Fortune 50 company say this week:
"What ever happened to that Ubuntu JeOS thing? We keep looking at CoreOS and Atomic, but what we really want is just a bare minimal Ubuntu server."Somehow, somewhere along the line, an important message a got lost. I hope we can correct that now...
JeOS has been here all along, in fact. You've been able to deploy a daily, minimal Ubuntu image, all day, every single day for most of the the last decade. Sure, it changed names to Ubuntu Core along the way, but it's still the same sleek little beloved ubuntu-minimal distribution.
"How minimal?", you ask...
63 MB compressed, to be precise.
Did you get that?
That's 63 MB, including a package management system, with one-line, apt-get access to over 30,000 freely available packages across the Ubuntu universe.
That's pretty darn small. Much smaller than say, 165 MB or 268 MB (which, to be fair, includes a bit more of an operating system -- much closer to say the standard Ubuntu Cloud Image, which is a 176 MB root tarball, or with kernel at 243 MB).
"How useful could such a small image actually be, in practice?", you might ask...
Ask any Docker user, for starters. Docker's base Ubuntu image has been downloaded over 775,260 to date. And this image is built directly from the Ubuntu Core amd64 tarball.
Oh, and guess what else? Ubuntu Core is available for more than just the amd64 architecture! It's also available for i386, armhf, arm64, powerpc, and ppc64el. Which is pretty cool, particularly for embedded systems.
So next time you're looking for just enough operating system, just look to the core. Ubuntu Core. There is truly no better starting point ;-)