Migrating from v1.x to v2.x

Hello –

I’d like to find more information about devices running RancherOS v1 and what to expect if/when Rancher Server is at v2. Are devices with Rancher OS v1 expected to transition from Docker to Kubernetes? Will the process be as easy as sudo ros os or would a reinstall required? I hope we are measuring the impact of Docker vs. Kubernetes on devices.

Nothing about the OS changes depending on whether you’re running Rancher 1.x or 2.x on it; Kubernetes is not a new operating system. RancherOS provides the Docker daemon on the host. Rancher (1.x and 2.x) run containers on hosts with Docker. The host OS doesn’t know or care whether they are scheduled by Kubernetes or Cattle or Mesos or Swarm, they are still just containers running on Docker.

Can you install (on the same nodes) Rancher 1.x and 2.x; and migrate from 1.x to 2.x? Without adding any new nodes?

Note: I’ve seen a demo of kubernetes on pi3, intel Nuc, and oDroid C2 (all in a single cluster!). It seems that kubernetes has a relatively low overhead.

If this is true, then RancherOS will not be depending on Kubernetes for OS? Please consider the responsibilities of /usr/bin/system-docker because it contains (heh) the OS. I’m worried that systemd will not fire off Docker containers system init… it will be firing off fleet, etc and so on.

This is troubling because I have not seen any benchmarks for Kubernetes on pi3 or other platforms. I’ve noticed Kubernetes having a much greater footprint (in addition to complexity) when compared to Docker.

I have RancherOS physically deployed – I’d like to maintain it’s current stability. If i cannot use ros os upgrade then I’d need to pull & replace a lot of gear (yikes).

No, RancherOS has nothing to do with Kubernetes. They are unrelated the same way Rancher 1.x and RancherOS are unrelated.

RancherOS is made up of docker containers (system-docker) and provides a (user) docker daemon.

Kubernetes is not an “alternative” to the Docker engine, it runs things on top of the Docker daemon/engine of a set of nodes. (Swarm mode in Docker is analogous to Kubernetes, but is a completely separate concern from the engine)

Kubernetes (as packaged by Rancher 2.0/RKE) consists of Docker containers which run on a docker daemon.

Both of those can be run on RancherOS, or anything else that provides the Docker daemon.