New CentOS Atomic Host Release Available for Download

An updated version of CentOS Atomic Host (tree version 7.1705), is now available. CentOS Atomic Host is a lean operating system designed to run Docker containers, built from standard CentOS 7 RPMs, and tracking the component versions included in Red Hat Enterprise Linux Atomic Host.

CentOS Atomic Host is available as a VirtualBox or libvirt-formatted Vagrant box, or as an installable ISO, qcow2 or Amazon Machine image. These images are available for download at cloud.centos.org. The backing ostree repo is published to mirror.centos.org.

CentOS Atomic Host includes these core component versions:

• atomic-1.17.2-4.git2760e30.el7.x86_64
• cloud-init-0.7.5-10.el7.centos.1.x86_64
• docker-1.12.6-28.git1398f24.el7.centos.x86_64
• etcd-3.1.7-1.el7.x86_64
• flannel-0.7.0-1.el7.x86_64
• kernel-3.10.0-514.21.1.el7.x86_64
• kubernetes-node-1.5.2-0.6.gitd33fd89.el7.x86_64
• ostree-2017.5-1.el7.x86_64
• rpm-ostree-client-2017.5-1.atomic.el7.x86_64

Containerized kubernetes-master

The downstream release of CentOS Atomic Host ships without the kubernetes-master package built into the image. Instead, you can run the master kubernetes components (apiserver, scheduler, and controller-manager) in containers, managed via systemd, using the service files and instructions on the CentOS wiki. The containers referenced in these systemd service files are built in and hosted from the CentOS Community Container Pipeline, based on Dockerfiles from the CentOS-Dockerfiles repository.

These containers have been tested with the kubernetes ansible scripts provided in the upstream contrib repository, and they work as expected, provided you first copy the service files onto your master.

Alternatively, you can install the kubernetes-master components using rpm-ostree package layering using the command: atomic host install kubernetes-master.

Upgrading

If you're running a previous version of CentOS Atomic Host, you can upgrade to the current image by running the following command:

$ sudo atomic host upgrade

Images

Vagrant

CentOS-Atomic-Host-7-Vagrant-Libvirt.box and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box are Vagrant boxes for Libvirt and Virtualbox providers.

The easiest way to consume these images is via the Atlas / Vagrant Cloud setup (see https://atlas.hashicorp.com/centos/boxes/atomic-host). For example, getting the VirtualBox instance up would involve running the following two commands on a machine with vagrant installed:

$ vagrant init centos/atomic-host && vagrant up --provider virtualbox 

ISO

The installer ISO can be used via regular install methods (PXE, CD, USB image, etc.) and uses the Anaconda installer to deliver the CentOS Atomic Host. This image allows users to control the install using kickstarts and to define custom storage, networking and user accounts. This is the recommended option for getting CentOS Atomic Host onto bare metal machines, or for generating your own image sets for custom environments.

QCOW2

The CentOS-Atomic-Host-7-GenericCloud.qcow2 image is suitable for use in on-premise and local virtualized environments. We test this on OpenStack, AWS and local Libvirt installs. If your virtualization platform does not provide its own cloud-init metadata source, you can create your own NoCloud iso image.

Amazon Machine Images

SHA Sums

46082267562f9eefbc4b29058696108f07cb0ceb2dafe601ec5d66bb1037120a  CentOS-Atomic-Host-7.1705-GenericCloud.qcow2
1bd6dfbe360be599a45734f03b34e08cc903630327e1c54534eb4218bf18d0da  CentOS-Atomic-Host-7.1705-GenericCloud.qcow2.gz
aa4a3ac057d3ea898bea07052aa9fd20c7ca7ea3c8a5474bca9227622915e5e2  CentOS-Atomic-Host-7.1705-GenericCloud.qcow2.xz
d99c2e9d1d31907ace3c1e54fc3087ebb9d627ca46168f7e65b469789cd39739  CentOS-Atomic-Host-7.1705-Installer.iso
cfd6a29e26e202476b6a2dc54b1b31321688270a6cc6a9ef4206ac0ebd0e309c  CentOS-Atomic-Host-7.1705-Vagrant-Libvirt.box
d9b5f965f637a909efa15cd43063729db002c012c81a8cde0de588ea0932f970  CentOS-Atomic-Host-7.1705-Vagrant-VirtualBox.box

Release Cycle

The CentOS Atomic Host image follows the upstream Red Hat Enterprise Linux Atomic Host cadence. After sources are released, they're rebuilt and included in new images. After the images are tested by the SIG and deemed ready, we announce them.

Getting Involved

CentOS Atomic Host is produced by the CentOS Atomic SIG, based on upstream work from Project Atomic. If you'd like to work on testing images, help with packaging, documentation -- join us!

The SIG meets weekly on Thursdays at 16:00 UTC in the #centos-devel channel, and you'll often find us in #atomic and/or #centos-devel if you have questions. You can also join the atomic-devel mailing list if you'd like to discuss the direction of Project Atomic, its components, or have other questions.

Getting Help

If you run into any problems with the images or components, feel free to ask on the centos-devel mailing list.

Have questions about using Atomic? See the atomic mailing list or find us in the #atomic channel on Freenode.