RancherOS v0.8.0 is now available! This release has taken a bit more time than prior versions, as we’ve been laying more groundwork to allow us to do much faster updates, and to release more often.

Release Highlights

Using the Linux 4.9.9 mainline kernel Using the mainline stable Linux kernel should allow us to give container users access to new features faster - and will mean that RancherOS will have a simpler debug and update path for other software too.

Placing the installer container image in the ISO This change allows users to install RancherOS without internet access, and simplifies automated testability of changes. This adds about 13MB to the ISO, but means that you can do a basic install of RancherOS without pulling an image from the Docker Hub.

Running cloud-init earlier in the boot process Previously, the cloud-init service ran late in the RancherOS boot process, which made it impossible to customize system services that ran before cloud-init. As of v0.8.0, the cloud-init service runs while RancherOS is still running from memory and before System Docker starts.

By running earlier in the boot process, we’ve enabled a wider range of different customizations to RancherOS. For example, now you can set HTTP proxy settings on System Docker or replace configuration files for services such as NTP. Having cloud-init run earlier also opens the ability to use other cloud-config keys that are only applicable early in the boot sequence, such as operations around disk formatting and running arbitrary commands and systems services while RancherOS is still running from memory.

Cloud-config validation Producing a valid cloud-config file is often frustrating due to the oddities and edge cases around YAML. A new command (ros config validate) has been created to help solve these issues. This command allows users to verify whether their cloud-config is valid for RancherOS. For each invalid component, a detailed error is provided to help users correct their cloud-config. Once the cloud-config passes our validation, users can confidently use it in RancherOS without the fear of a missing space or missing dash causing their cloud-config to be ignored.

Syslinux bootloader everywhere To simplify the installation code, we went from a mixture of GRUB and Syslinux, to using Syslinux only. For now, the Syslinux boot prompt is only visible for one second - to interrupt, you’ll need to type a character quickly - and then to add boot parameters, replace that with rancheros-v0.8.0 rancher.autologin=tty1, or whatever you want to add. We are discussing changing the default boot process to autologin on the physical console (see the discussion on GitHub).

New ZFS service We moved away from using an Ubuntu kernel, so using ZFS via an Ubuntu persistent console no longer works. In v0.8.0, the new ZFS service installs the kernel-header service, downloads the OpenZFS source code, compiles it, and then creates and starts a new zfs-tools service which proves the zfs tools to the console. It takes a bit longer to install because it compiles from source, but we’ll work on adding pre-built modules as we work on our build systems which should consequently speed things up.

Boot time and error logging to dmesg To help debug issues in the installer and early cloud-init, we added more boot time diagnostics. At least for a few releases, we’ll be throwing a lot more logging both at the boot console, and at /dev/kmsg. Please tell us if these changes are causing you issues! The best ways to let us know are via GitHub or our forums.

Other minor fixes We’ve made a few additional small, but notable changes:

  • Fixed issues with VMware open-vm-tools and Virtualbox
  • Rewritten the installer and other scripts in Go
  • System console image and service definitions move some RancherOS customization out of the Dockerfile

RancherOS now available in AWS GovCloud region

RancherOS Linux is now available on the GovCloud isolated AWS Region for US government agencies and organizations. Combining RancherOS with GovCloud provides users with a safe way to build systems for sensitive and regulated data or workflows, and we’re pleased to make this combined solution available for our customers.

Next release

Across Rancher Labs, we’ve committed to smaller and more regular releases – which means RancherOS v0.9.0 should be out in about a month with a much more digestible change list. Until then, expect to see regular point releases with fixes and updated kernels (v0.8.1 is shaping up to have Linux 4.9.11). As a new member of the Rancher team, this version of RancherOS is the first one for which I’ve been the release manager, and we welcome your feedback online – you can follow me @SvenDowideit or let us know how you like these changes @Rancher_Labs.