While Chapter 9, Rancher, is dedicated entirely to Rancher, it does not cover the container-optimized operating system. Instead, it talks about Rancher the orchestration tool. The Rancher project (https://rancher.com/) distributes RancherOS to compliment its orchestration system.
To launch a RancherOS host locally using VirtualBox, run the following:
docker-machine create -d virtualbox
--virtualbox-boot2docker-url https://releases.rancher.com/os/latest/rancheros.iso
docker-rancher
You'll receive the following message:
(docker-rancher) Boot2Docker URL was explicitly set to "https://releases.rancher.com/os/latest/rancheros.iso" at create time, so Docker Machine cannot upgrade this machine to the latest version.
This means that you will not be able to use the docker-machine upgrade command. Docker Machine will use the RancherOS provisioner, and once it's complete, you will be able to check the release file by running the following:
$ docker-machine ssh docker-rancher cat /etc/*release
This will return something similar to the following:
DISTRIB_ID=RancherOS
DISTRIB_RELEASE=v1.0.2
DISTRIB_DESCRIPTION="RancherOS v1.0.2"
NAME="RancherOS"
VERSION=v1.0.2
ID=rancheros
ID_LIKE=
VERSION_ID=v1.0.2
PRETTY_NAME="RancherOS v1.0.2"
HOME_URL="http://rancher.com/rancher-os/"
SUPPORT_URL="https://forums.rancher.com/c/rancher-os"
BUG_REPORT_URL="https://github.com/rancher/os/issues"
BUILD_ID=
Let's check the version of Docker that is installed by running this command:
$ docker $(docker-machine config docker-rancher) version
It shows that the Docker version bundled with RanchOS is more recent than the version that is part of CoreOS:
Client:
Version: 17.03.1-ce
API version: 1.27
Go version: go1.7.5
Git commit: c6d412e
Built: Tue Mar 28 00:40:02 2017
OS/Arch: darwin/amd64
Server:
Version: 17.03.1-ce
API version: 1.27 (minimum version 1.12)
Go version: go1.7.5
Git commit: c6d412e
Built: Tue Mar 28 00:40:02 2017
OS/Arch: linux/amd64
Experimental: false
To remove the local RancherOS host, just run docker-machine rm -f docker-rancher.
For more information on RancherOS, you can view the project's website at http://rancher.com/rancher-os/ or the code base on GitHub at https://github.com/rancher/os/.