RancherOS v0.2
UpgradeThis week we released RancherOS 0.2, which introduces support for upgrades. RancherOS is a tiny Linux distribution designed specifically to run Docker, using containers to isolate user and system processes. Given that RancherOS does just about everything with containers, it shouldn’t be a surprise that upgrading a RancherOS node is almost exactly like upgrading a Docker container. All of the upgrade procedures in RancherOS are accessed through the \“rancherctl\” system service. Use the following command to determine the current version of RancherOS that you’re using:

sudo rancherctl -v

Use \“os list\” to see the other RancherOS versions currently available to download:

sudo rancherctl os list

The output should display a list of both remote and local OS versions similar to the following:

rancher/os:v0.1.2 remote
rancher/os:v0.2.0 remote
rancher/os:v0.2.0 local
rancher/os:v0.2.1 remote
rancher/os:v0.2.2 remote

To upgrade to the latest version, just issue an \“os upgrade\” command.

sudo rancherctl os upgrade

All of the versions of RancherOS are packaged in Docker images on DockerHub, so once you’ve directed RancherOS to upgrade, it will automatically pull the images down to your machine, and finally confirm that you want to upgrade and reboot the host. Once you have rebooted, you can confirm the upgrade using the \“rancherctl -v\” command. If at any point you want to roll back, or upgrade to a specific version \“upgrade -i\” allows you to specify the exact version you want to upgrade to. For example:

sudo rancherctl os upgrade -i rancher/os:v0.2.0

Darren Shepherd provides a quick demonstration of how to install and then upgrade a RancherOS 0.2 environment below. RancherOS 0.2 also includes a number of bug fixes, more configurability, hyper-v support, and greatly improved vagrant support. If you’re interested in learning more, please register for our first RancherOS online meetup on March 31st.