An updated version of CentOS Atomic Host (version 7.20160203) is now available for download. 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 7.2.

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(http://cloud.centos.org/centos/7/atomic/images/). The backing ostree repo is published to mirror.centos.org(http://mirror.centos.org/centos/7/atomic/x86_64/repo).

CentOS Atomic Host includes these core component versions:

* kernel-3.10.0-327.4.5.el7.x86_64 * cloud-init-0.7.5-10.el7.centos.1.x86_64 * atomic-1.6-6.gitca1e384.el7.x86_64 * kubernetes-1.0.3-0.2.gitb9a88a7.el7.x86_64 * etcd-2.1.1-2.el7.x86_64 * ostree-2015.9-2.atomic.el7.x86_64 * docker-1.8.2-10.el7.centos.x86_64 * flannel-0.5.3-8.el7.x86_64

## 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 (http://cloud.centos.org/centos/7/atomic/images/CentOS-Atomic-Host-7-Vagrant -Libvirt.box) (416 MB) and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box (http://cloud.centos.org/centos/7/atomic/images/CentOS-Atomic-Host-7-Vagrant -Virtualbox.box) (428 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 (http://cloud.centos.org/centos/7/atomic/images/CentOS-Atomic-Host-7-Install er.iso) (737 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.

### QCOW2

The CentOS-Atomic-Host-7-GenericCloud.qcow2 (http://cloud.centos.org/centos/7/atomic/images/CentOS-Atomic-Host-7-Generic Cloud.qcow2) (1 GB) 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(http://www.projectatomic.io/blog/2014/10/getting-started-with-cloud-init /) NoCloud iso image.

### Amazon Machine Images

Region Image ID ------ --------

us-east-1 ami-896653e3 us-west-2 ami-1f94747f us-west-1 ami-dae791ba eu-west-1 ami-430aba30 eu-central-1 ami-40d6cd2c ap-southeast-1 ami-4319d720 ap-northeast-1 ami-b54d4adb ap-southeast-2 ami-27123544 ap-northeast-2 ami-961fd1f8 sa-east-1 ami-238d0e4f

### SHA Sums

4062ef213eed698ac8ec03b32a55dd6903721a44dc8d54a18513644f160ca7d4 CentOS-Atomic-Host-7.20160130-GenericCloud.qcow2 a7dd91736f45101e95e7d9a80c2eede9164eb0392c8c4748b08c98a42d3eda39 CentOS-Atomic-Host-7.20160130-GenericCloud.qcow2.gz 9eca81d3638e4e00fc734d7233b47a3af803237cc82e5a66b3a587552232dcdc CentOS-Atomic-Host-7.20160130-GenericCloud.qcow2.xz be3c1a3326c04026f37bd6b6c2fccca3a285ea40ac663230624854abeaaee135 CentOS-Atomic-Host-7.20160130-Installer.iso 90942c3599e15ae21cdc0b1682b8e0d3fa88f8db2f6fdca0ece28c2bffdbb34f CentOS-Atomic-Host-7.20160130-Vagrant-Libvirt.box ce674573f6d7020b3d04c51f070d7172e71b6a4316c1495c238a7eac0260cb5a CentOS-Atomic-Host-7.20160130-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 (http://wiki.centos.org/SpecialInterestGroup/Atomic), based on upstream work from Project Atomic (http://www.projectatomic.io/). 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 (https://lists.projectatomic.io/mailman/listinfo/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 (http://lists.centos.org/mailman/listinfo/centos-devel) mailing list.

Have questions about using Atomic? See the atomic (https://lists.projectatomic.io/mailman/listinfo/atomic) mailing list or find us in the #atomic channel on Freenode.

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Jason Brooks Red Hat Open Source and Standards

@jasonbrooks | @redhatopen http://community.redhat.com