Clear Containers requires additional resources to create a virtual machine
container. These resources are called
Clear Container assets
which are a kernel and a root filesystem image. This document describes when
these components are updated.
The Clear Containers kernel is a
Linux* kernel based on the latest vanilla version of the
Longterm kernel and the includes
patches necessary to run
Clear Containers. The Longterm branch is only updated with
important bug fixes
and in turn using this branch ensures fewer required updates.
Each time a new kernel version is rolled out it is updated in the Clear Containers packaging repository and the Clear Containers Linux kernel. On each Clear Containers release the latest version in this repository is used as the recommended kernel for the new Clear Containers version.
The Clear Containers image known as the "mini O/S" is produced from Clear Linux* operating system packages/bundles. The image is generated multiple times a day as part of the Clear Linux release cycle.
The Clear Containers image is updated only when critical updates are done to the packages used by the Clear Containers guest OS:
- Systemd
- Clear Containers Agent
- iptables
- core-utils
This is verified each release using the
get-image-changes.sh
script.
The image must be updated in the Clear Containers packaging repository and defined in the versions.txt file.
Official Clear Containers Packages are hosted in the OBS build system. In order to avoid availability issues the kernel and image for the Clear Containers continuous integration system used are downloaded from Clear Linux* packages:
https://download.clearlinux.org/releases/${CLEAR_VERSION}/clear/x86_64/os/Packages/linux-container-${KERNEL_VERSION}.rpm
https://download.clearlinux.org/releases/${CLEAR_VERSION}/clear/clear-${CLEAR_VERSION}-containers.img.xz
In the case of critical updates to the kernel or the Clear Containers image a new Clear Containers release will be rolled out immediately.