Rancher Labs, Leveraging Container Tech, Releases World's Lightest Linux Distribution For Servers

Rancher Labs released its ultra-lightweight Linux distribution on Tuesday, a product that illustrates how the container tech revolution is creating room for innovation in the operating system.

RancherOS, an operating system built from containers and geared exclusively for hosting them, achieves an unprecedentedly small footprint by eliminating Linux system libraries and utilities outside the kernel. Those often-extraneous components can be reintroduced separately in Docker containers when needed.

With all traditional OS functions atomized in containers, RancherOS achieves rapid boot times and unique efficiencies that improve operation and scaling of distributed applications built as containerized micro-services, said Sheng Liang, CEO of the startup based in Cupertino, Calif.

[Related: Get On Board: Docker's Channel Maturity Unlocks The Container Tech Opportunity ]

Rancher, founded in 2014, has made a name for itself with its container management platform, an open source solution for managing large Docker clusters orchestrated by Kubernetes, Docker Swarm or Mesos.

But back in early 2015, about the same time it released the management platform, Rancher also introduced a unique operating system — what at the time was essentially a conceptual idea.

Initially, mostly hobbyists and technologists were interested in playing with the stripped-down Linux distribution. The product, however, became more practical about a year ago, and Rancher started seeing it implemented in production environments. Last year the company even signed a few support contracts.

"It takes a long time to really stabilize and mature the operating system," Liang said. "We finally got to the point where there was enough community traction, paying users, people who want us to support it commercially."

The advent of containers has ushered in new efforts to innovate at the level of the operating system.

"Linux was a mature, well-established space. Then containers created a lot of experimentation around the OS," Liang said.

That started with CoreOS, another major container tech player. The San Francisco-based startup was the first to strip down Linux to maximize the efficiency of distributed systems architected with Docker containers.

RancherOS took that idea to a new extreme, slicing and dicing until what remained needed a fraction of the disk space required by CoreOS and other lightweight Linux distributions, Liang told CRN.

Rancher's insight, he said, was that Docker made it possible to avoid packaging and certifying the traditional system components into the Linux release. Those applications could always be added, with the Docker Compose tool used to define a set of required services.

"What the Linux distro has to do is a lot less. We just need to be a place around the containers, and the container ecosystem can package and distribute apps. The operating system becomes a lot smaller, a lot easier," he said.

The small footprint also reduces the number of updates and patches, further simplifying use, while leaving fewer security vulnerabilities, according to Liang. So far, most production implementations of RancherOS are running on bare-metal or Amazon Web Services, he added.

Rancher's emerging partner base is expressing interest in RancherOS, Liang said. Rancher will soon include the product – a subscription support service – in a partner program it launched late last year.

"Partners historically have moved a lot of OS licenses," Liang said. "So this will naturally be part of our channel program."

But Rancher's attempt to reimagine operating system basics still has a lot to prove, as does the business model of selling a subscription support service for that kind of product, according to Chris Ciborowski, CEO of Nebulaworks, a container-focused solution provider based in Southern California.

"It's a nice idea," Ciborowski said of leveraging Docker containers to install and run other utilities. But Rancher's approach, which requires running two Docker daemons, also adds a new element of complexity.

"The real question to ask is what role the Linux distro plays," Ciborowski told CRN.

When taking a cloud-native approach to infrastructure, Linux virtual machines certainly should be extremely lightweight, with minimal tools and utilities installed. At the same time, troubleshooting and root cause analysis shouldn't be handled at the level of Linux, but rather correlated from telemetry data from other parts of the environment, like apps and orchestration services.

So while it might make sense for resellers to offer RancherOS on their line cards, with "infrastructure implemented and managed correctly" a support contract for any host OS could, for some customers, be an unnecessary expense, Ciborowski said.