An updated version of CentOS Atomic Host (tree version 7.20161006), is now available, featuring the option of substituting the host's default docker 1.10 container engine with a more recent, docker 1.12-based version, provided via the docker-latest package.

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-1.10.5-7.el7.x86_64
• cloud-init-0.7.5-10.el7.centos.1.x86_64
• docker-1.10.3-46.el7.centos.14.x86_64
• etcd-2.3.7-4.el7.x86_64
• flannel-0.5.3-9.el7.x86_64
• kernel-3.10.0-327.36.1.el7.x86_64
• kubernetes-1.2.0-0.13.gitec7364b.el7.x86_64
• ostree-2016.7-2.atomic.el7.x86_64

docker-latest

You can switch to the alternate docker version by running:

# systemctl disable docker --now
# systemctl enable docker-latest --now
# sed -i '/DOCKERBINARY/s/^#//g' /etc/sysconfig/docker

Because both docker services share the /run/docker directory, you cannot run both docker and docker-latest at the same time on the same system.

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 (546 MB) and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box (558 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

ISO

The installer ISO (776 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 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 (1.2 GB) 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

Region         Image ID
------         --------
ap-northeast-1 ami-494e9628 
ap-northeast-2 ami-07bb6f69 
ap-southeast-1 ami-60b51203 
ap-southeast-2 ami-598cbf3a 
eu-central-1   ami-6350af0c 
eu-west-1      ami-8c2c6fff 
sa-east-1      ami-5a51c336 
us-east-1      ami-cfeca0d8 
us-west-1      ami-71bef711 
us-west-2      ami-f020f890

SHA Sums

3af63166dd86c0b719efb57b5b4cc0997b959caa6680d3f86ff710bc382a2bd6 CentOS-Atomic-Host-7.1609-GenericCloud.qcow2
4ab6c62710cf81ae1e632c428a915648e3573adddab9f9c5d6fed517dcf27553 CentOS-Atomic-Host-7.1609-GenericCloud.qcow2.gz
06549195aa626b82f9b7473a366a7f1b32932dff60e8d53be924b3b0c2635e00 CentOS-Atomic-Host-7.1609-GenericCloud.qcow2.xz
e26651dd1c3dde5b6dfee088876189fb29fb79f729e86fcd516fe87ccd992381 CentOS-Atomic-Host-7.1609-Installer.iso
037dad130293cf7476e9d711fec0d40d88f370f36dae66b80c8cce4ab5082fc2 CentOS-Atomic-Host-7.1609-Vagrant-Libvirt.box
1353920c87b0516c44072a184bbb8845c89ba1e538185a4dfc03076f65401dca CentOS-Atomic-Host-7.1609-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.