Home » New CentOS Atomic Host supports Docker

New CentOS Atomic Host supports Docker

Source: Jason Brooks

(Sept. 10) — Today we’re releasing a significant update to the CentOS Atomic Host (version 7.20150908), 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, as an installable ISO image, as a qcow2 image, or as an Amazon Machine Image. These images are available for download at cloud.centos.org. The backing ostree repo is published to mirror.centos.org.

Currently, the CentOS Atomic Host includes these core component versions:

  • kernel 3.10.0-229
  • docker 1.7.1-108
  • kubernetes 1.0.0-0.8.gitb2dafda
  • etcd 2.0.13-2
  • flannel 0.2.0-10
  • cloud-init 0.7.5-10
  • ostree 2015.6-4
  • atomic 1.0-108


If you’re running the version of CentOS Atomic Host that shipped in June, you can upgrade to the current image by running the following command:

$ sudo atomic host upgrade

If you’re currently run the older, test version of the CentOS Atomic Host, or if you’re running any other atomic host (from any distro or release in the past), you can rebase to this released CentOS Atomic Host by running the following two commands :

$ sudo ostree remote add centos-atomic-host http://mirror.centos.org/centos/7/atomic/x86_64/repo
$ sudo rpm-ostree rebase centos-atomic-host:centos-atomic-host/7/x86_64/standard



CentOS-Atomic-Host-7-Vagrant-Libvirt.box (393 MB) and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box (404 MB) 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


The installer ISO (682 MB) can be used via regular install methods (PXE, CD, USB image, etc.) and uses the Anaconda installer to deliver the CentOS Atomic Host. This allows flexibility to control the install using kickstarts and define custom storage, networking and user accounts. This is the recommended process for getting CentOS Atomic Host onto bare metal machines, or to generate your own image sets for custom environments.


The CentOS-Atomic-Host-7-GenericCloud.qcow2 (922 MB) 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. The Generic Cloud image is also available compressed in gz (389 MB) and xz compressed (303 MB) formats.

Amazon Machine Images

Region         Image ID
------         --------
sa-east-1      ami-47ed785a
ap-northeast-1 ami-3458d234
ap-southeast-2 ami-05511e3f
us-west-2      ami-a5b6ab95
ap-southeast-1 ami-dc99938e
eu-central-1   ami-8c111191
eu-west-1      ami-0b6e4d7c
us-west-1      ami-69679d2d
us-east-1      ami-69c3aa0c

SHA Sums

a132d59732e758012029a646c466227f4ecf0c71cc42f0a10d3672908e463c0c CentOS-Atomic-Host-7.20150908-GenericCloud.qcow2
aad5d39e0683dc997f34902b068c7373aac3f7dc9b2c962a6ac0fe7394e2aa58 CentOS-Atomic-Host-7.20150908-GenericCloud.qcow2.gz
c8432175a012e7f13b7005fe9c1fe43e03e47ca433db8230ab6d5d1831d2cbe0 CentOS-Atomic-Host-7.20150908-GenericCloud.qcow2.xz
b222702942d02da2204581de6f877cf93289459a99f9080e29016e3b90328098 CentOS-Atomic-Host-7.20150908-Installer.iso
5531fa99429b38c6e6c4aca87672bd5990ab90f6445cc0e55c9121ad62229141 CentOS-Atomic-Host-7.20150908-Vagrant-Libvirt.box
bdcf58772117dd3a84100e5902f4f345daeea7c04f057c0ab6e29bfef3c82eab CentOS-Atomic-Host-7.20150908-Vagrant-Virtualbox.box

Release Cycle

The rebuild image will follow the upstream Red Hat Enterprise Linux Atomic Host cadence. After sources are released, they’ll be rebuild and included in new images. After the images are tested by the SIG and deemed ready, they’ll be announced. If you’d like to help with the process, there’s plenty to do!

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, or even help define the direction of our monthly release — 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.