The CentOS Infrastructure team will be moving the machines hosting cbs.centos.org, ci.centos.org and accounts.centos.org on October 10th, 2016. We expect a downtime of 48hrs. Contact us in #centos-devel on freenode at any time during that period for questions, or watch the centos-devel mailing list for the latest updates.

The servers, switches, PDUs, and even the racks themselves hosting CBS, ci.centos.org, accounts.centos.org and registry.centos.org are all stored in a datacenter in Raleigh, North Carolina, USA and will be moved to a new space in the datacenter on Monday October 10th. This new space provides a little bit of expansion room for the future of these services and consolidates networks that were previously separate (namely the CICO cloud with the rest of the CI infrastructure). During this window, all services related to the listed CentOS properties will be down.

We blocked out 2 days (48hrs) to do the move, but we will do our best to restore services as soon as it is possible to do so.

UPDATE 2016-09-08: Due to additional checks, we had to retire v1608.01 from Atlas and release it again as v1608.02. The two versions are identical.

Official Vagrant images for CentOS Linux 6 and CentOS Linux 7 for x86_64 are now available for download, featuring updated packages to 31 August 2016, as well as a new image for VMware Fusion.

Known Issues

  1. The VirtualBox Guest Additions are not preinstalled; if you need them for shared folders, please install the vagrant-vbguest plugin. We recommend using NFS instead of VirtualBox shared folders if possible.
  2. Since the Guest Additions are missing, our images are preconfigured to use rsync for synced folders. Windows users can either use SMB for synced folders, or disable the sync directory by adding the line config.vm.synced_folder ".", "/vagrant", disabled: true to the Vagrantfile.
  3. Vagrant 1.8.5 is unable to create new Linux boxes due to Vagrant bug #7610. You can use Vagrant 1.8.4 until version 1.8.6 is released.

Downloads

The official images can be downloaded from Hashicorp’s Atlas. We provide images for libvirt, VirtualBox and VMware.

If you never used our images before:

$ vagrant box add centos/6 # for CentOS Linux 6
$ vagrant box add centos/7 # for CentOS Linux 7

Existing users can upgrade their images by:

$ vagrant box update --box centos/6
$ vagrant box update --box centos/7

Checksums

The downloaded images should have the following SHA256 checksums:

914ab02db12f2d19f71dbd3c6cb171dff683893443e26f2f03160491945366dc  CentOS-6-x86_64-Vagrant-1608_01.LibVirt.box
5391ea7bdafafe8d8df58b8405d81cafdcd0b8273c18cdd37133dcf1cb329a0b  CentOS-6-x86_64-Vagrant-1608_01.VirtualBox.box
4d6a5906ada93a5228f62671f7c97bed0ae3c961df108c25ceee278a8d9d17d2  CentOS-6-x86_64-Vagrant-1608_01.VMwareFusion.box
2916442968486a41315cb93d35fbbaeaf72e200f051f4996b5766649b8c3a325  CentOS-7-x86_64-Vagrant-1608_01.LibVirt.box
415b79487cdb7e0246ef93585de08d2063b1e7b85ff5666f60de5cb96a4a027c  CentOS-7-x86_64-Vagrant-1608_01.VirtualBox.box
44d26155e89fa5d74994167489bd66da4187b3da02ac3a063f0b26cfab965baf  CentOS-7-x86_64-Vagrant-1608_01.VMwareFusion.box

Vagrant has the ability to verify that the downloaded image has a specific checksum, e.g.

$ vagrant box add --checksum-type sha256 --checksum 2916442968486a41315cb93d35fbbaeaf72e200f051f4996b5766649b8c3a325 --provider libvirt centos/7

Unfortunately, this is not possible with vagrant box update.

Feedback

If you encounter any unexpected issues with the Vagrant images, feel free to ask on the centos-devel mailing list, or in #centos-devel on Freenode.

Since yesterday, we have production-ready automated tests for our Vagrant images on ci.centos.org, fully integrated with GitHub. We were only able to build and test scratch images manually until now, which was time consuming and had the disadvantage that, due to hardware limitations on my side, only the images for VirtualBox were actually tested.

A pull request to the CentOS/sig-cloud-instance-build repository on GitHub will trigger the cloudinstance-vagrant-build Jenkins job on ci.centos.org, which builds all Vagrant images in CBS. If the build process completes without errors, the cloudinstance-vagrant-test job will test the Vagrant images for both CentOS Linux 6 and CentOS Linux 7, using the libvirt and virtualbox Vagrant providers. If everything is ok, you can see the test result directly below the pull request on GitHub (please note that a full test currently needs almost two hours to complete, most of the time being spent building the images):

Screenshot of a successful test, taken on GitHub

Most of the code for the test is in my cloudinstance-vagrant-cico-util repository on GitHub, with a few additional snippets in the Jenkins configuration for each job. We are using the latest Vagrant provided by the Software Collections SIG, and VirtualBox 5.0.26 from virtualbox.org (at the time of writing this post, Vagrant refuses to start if it detects VirtualBox 5.1). Feedback is of course welcome.

An updated version of CentOS Atomic Host (tree version 7.20160818), featuring support for rpm-ostree package layering, is available for download. Using the command rpm-ostree pkg-add, it’s now possible to layer new packages into an installed image that persist across reboots and upgrades.

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:

  • docker-1.10.3-46.el7.centos.10.x86_64
  • kubernetes-1.2.0-0.13.gitec7364b.el7.x86_64
  • kernel-3.10.0-327.28.2.el7.x86_64
  • atomic-1.10.5-7.el7.x86_64
  • flannel-0.5.3-9.el7.x86_64
  • ostree-2016.7-2.atomic.el7.x86_64
  • etcd-2.3.7-2.el7.x86_64
  • cloud-init-0.7.5-10.el7.centos.1.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 (530 MB) and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box (541 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 (757 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 (1.1 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

us-east-1      ami-d43d5dc3 
us-west-2      ami-0227f362 
us-west-1      ami-52df9d32
eu-west-1      ami-ed4b3d9e 
eu-central-1   ami-014abb6e 
ap-southeast-1 ami-27a27a44 
ap-northeast-1 ami-4d35fa2c 
ap-southeast-2 ami-65b18606
ap-northeast-2 ami-12ae7b7c 
sa-east-1      ami-6ed34202

SHA Sums

5e2d2bc26d4017f556d3f1e65b6cf1a8ca111534515bbb7a6fea3d446af1b674 CentOS-Atomic-Host-7.1607-GenericCloud.qcow2 c8e908072b63581a7c8a3ffc2658eaf64cb30e1f85db7ed97d1e7fa3605dc26f CentOS-Atomic-Host-7.1607-GenericCloud.qcow2.gz 99776addb6ab2ff25d64831a21eb0c7bfe337be68d402095fd740c05f5d40a3e CentOS-Atomic-Host-7.1607-GenericCloud.qcow2.xz 05ccc8c1db8047028fabb92c89c3fda9f07286f5e7f2832c9ee92a05bf1bc8dc CentOS-Atomic-Host-7.1607-Installer.iso 443af2e145370dee939eaab38df9a61a15a0aa1636e477acb7864a175f78b584 CentOS-Atomic-Host-7.1607-Vagrant-Libvirt.box 7fef5a9c02c4c351f051f73e00f24d3a7ce8c0a081ae0f0956eb820b1211dd06 CentOS-Atomic-Host-7.1607-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.

Official Vagrant images for CentOS Linux 6 and CentOS Linux 7 for x86_64 are now available for download, featuring updated packages to 28 July 2016 and the following improvements:

  • Follow upstream Vagrant recommendations:
    • The default Vagrant sync directory is set to /vagrant
    • sshd DNS lookups are disabled by default
    • The root password is set to vagrant
  • The GRUB timeout is set to just 1 second, to decrease the boot time
  • [security]: sshd password authentication is now disabled (the vagrant user is configured with the publicly-known password vagrant and passwordless sudo, making it trivial for third-parties to gain administrative access via ssh if password authentication is enabled). You can still login as root or vagrant by entering the password on the console, if needed. We recommend re-creating all Vagrant boxes that were configured with private or public networking in the Vagrantfile.

Known Issues

  • The VirtualBox Guest Additions are not preinstalled, and there are currently no concrete plans of adding them. They are only needed for VirtualBox shared folders (host-only networking and forwarded ports work properly without the Guest Additions). We recommend using NFS instead of VirtualBox shared folders if possible, since the latter are significantly slower and files can be corrupted or not properly updated when sendfile is enabled. If you still want to install the Guest Additions, you can try either vbguest or, if you already use Ansible, take a look at https://github.com/lpancescu/cloud-instance-starter-kit for an example of automatic installation.
  • The default sync directory is configured to use rsync. This might cause vagrant up to fail on Windows, where rsync is not installed by default. As a workaround, Windows users can either install rsync via Cygwin or MSYS, or disable the sync directory by adding the line config.vm.synced_folder ".", "/vagrant", disabled: true to the Vagrantfile.
  • Vagrant 1.8.5 sets the permissions on ~vagrant/.ssh/authorized_keys to 0644 (world-readable) when replacing the insecure public key with a newly generated one. Since sshd will only accept keys readable just by their owner, vagrant up returns an error, since it cannot connect with the new key and it already removed the insecure key. This is Vagrant bug #7610, which affects all Linux distributions (not just CentOS); you can either downgrade to Vagrant 1.8.4 or wait for 1.8.6 to be released.

Downloads

Only x86_64 images are currently available, for Vagrant’s libvirt and VirtualBox providers.

First-time users can download the official images from Hashicorp’s Atlas. You can use vagrant box add centos/6 for CentOS Linux 6, or vagrant box add centos/7 for CentOS Linux 7.

Existing users can upgrade their boxes directly by Vagrant, e.g. vagrant box update --box centos/7, but the changes will only apply to newly created instances.

Feedback

If you encounter any unexpected issues with the Vagrant images, feel free to ask on the centos-devel mailing list, or in #centos-devel on Freenode.

Acknowledgements

We would like to thank Nico Kadel-Garcia for his valuable insight on preventing sshd from performing reverse DNS lookups.

Official Vagrant images for CentOS Linux 6 and CentOS Linux 7 for x86_64 are now available for download, featuring updated packages to 1st July 2016 and some improvements:

  • the default timezone is set to UTC (instead of New York, USA)
  • NTP is enabled by default (using ntpd on CentOS Linux 6 and chrony on CentOS Linux 7)
  • yum-utils is installed by default on CentOS Linux 7, providing needs-restarting

Known Issues

  • The Vagrant sync folder is /home/vagrant/sync instead of /vagrant (which is the Vagrant default). This will be changed in the next release.
  • The root password is set to a random string, instead of “vagrant”. Use sudo as the vagrant user to gain administrative privileges, no password is required.
  • The VirtualBox Guest Additions are not preinstalled, and there are currently no plans of adding them. They are only needed for shared folders; host-only networking and forwarded ports work, although Vagrant displays a warning to the contrary. If you use Ansible, take a look at https://github.com/lpancescu/cloud-instance-starter-kit for an example of automatic installation. The vagrant-vbguest plugin might also work (not tested).

Downloads

Only x86_64 images are currently available, for Vagrant’s libvirt and VirtualBox providers.

First-time users can download the official images from Hashicorp’s Atlas. You can use vagrant box add centos/6 for CentOS Linux 6, or vagrant box add centos/7 for CentOS Linux 7.

Existing users can upgrade their boxes directly by Vagrant, e.g. vagrant box update --box centos/7, but the changes will only apply to newly created instances.

Feedback

If you encounter any unexpected issues with the Vagrant images, feel free to ask on the centos-devel mailing list, or in #centos-devel on Freenode.

An updated version of CentOS Atomic Host (tree version 7.20160707) is now available for download, featuring updated versions of docker (1.10.3) and the atomic run tool (1.10.5). 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:

  • docker-1.10.3-44.el7.centos.x86_64
  • kubernetes-1.2.0-0.12.gita4463d9.el7.x86_64
  • kernel-3.10.0-327.22.2.el7.x86_64
  • atomic-1.10.5-5.el7.x86_64
  • flannel-0.5.3-9.el7.x86_64
  • ostree-2016.5-3.atomic.el7.x86_64
  • etcd-2.2.5-2.el7.0.1.x86_64
  • cloud-init-0.7.5-10.el7.centos.1.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 (467 MB) and CentOS-Atomic-Host-7-Vagrant-Virtualbox.box (477 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 (751 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 (1.1 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 
------         --------
us-east-1      ami-956fe882 
us-west-2      ami-17569677 
us-west-1      ami-191e5879 
eu-west-1      ami-a06601d3 
eu-central-1   ami-c431dbab 
ap-southeast-1 ami-9638e5f5 
ap-northeast-1 ami-fc867b9d 
ap-southeast-2 ami-6fab800c 
ap-northeast-2 ami-aca369c2 
sa-east-1      ami-30f96d5c

SHA Sums

0eb6fe98706c72635d2f156d3f9cbc4447db3234dafd792ed2b966a562695dcf CentOS-Atomic-Host-7.1606-GenericCloud.qcow2 
3af5dba377f31f52817820f8b940d0490da11d74d01edd70182171f21382fc65 CentOS-Atomic-Host-7.1606-GenericCloud.qcow2.gz 
d28b3f21de85c6c072e277bf873d1657364f6b82f08c91b05ed001ceadb07b79 CentOS-Atomic-Host-7.1606-GenericCloud.qcow2.xz 
ee98acb5a50288e03dc052d4ae5cf0ccbab518f2f15f35500217c90d8088d627 CentOS-Atomic-Host-7.1606-Installer.iso 
43ca397be511a32b3c750a73474039f965d6cc5c7dcfb74846e66366f5d758db CentOS-Atomic-Host-7.1606-Vagrant-Libvirt.box 
d458714f89b1ee3d4e4b7b097877cec9ceec5e651fec9374b4457e5a6c172f3d CentOS-Atomic-Host-7.1606-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.

I’ve been asked a few times about running virtual machines on the ARMv8 AArch64 platform, so it may be time to document the procedure.
There are a few packages you’ll need to make this happen, so lets install them first. The AAVMF package is the one noticeable difference between AArch64 and x86_64. It contains the needed UEFI loaders for the vm to function properly.

[root@aarch64 ~]# yum install NetworkManager libvirt libvirt-daemon virt-install qemu-img-ev qemu-kvm-ev AAVMF

Most users will want a bridged network, so we need to create one. I find it easiest (and safest) to do this with nmcli from the local console, but you’re free to do it however you wish. The commands below will remove the default eth0 interface configuration, create a bridge, and add eth0 to that bridge. Once that’s done, we start up the libvirt daemon and make sure it starts on boot.

[root@aarch64 ~]# nmcli con delete eth0
[root@aarch64 ~]# nmcli con add type bridge ifname br0 stp no
[root@aarch64 ~]# nmcli con add type bridge-slave ifname eth0 master br0
[root@aarch64 ~]# systemctl enable libvirtd
[root@aarch64 ~]# systemctl start libvirtd

Now that we have our bridge enabled and libvirtd is running, we can create our virtual machine. I use the virt-install command below to initialize a vm with 2 gigs of ram, and 10G of disk space via a kickstart install. Example kickstarts for various tasks will be published soon at https://github.com/CentOS/AltArch


virt-install --name centos-7-aarch64 \
--initrd-inject kickstart.ks \
--extra-args "ks=file:/kickstart.ks" \
--disk=pool=default,size=10,format=qcow2,bus=virtio \
--memory 2048 \
--location 'http://mirror.centos.org/altarch/7/os/aarch64/'

Once the installation is complete, the system will reboot and the vm will be ready to use. A quick virsh list will show that the guest vm is active, and a virsh console will give you console access to the vm, just as you’d expect on an x86_64 system.


[root@aarch64 ~]# virsh list
Id Name State
----------------------------------------------------
3 centos-7-aarch64 running

[root@aarch64 ~]# virsh console centos-7-aarch64
CentOS Linux 7 (AltArch)
Kernel 4.2.0-0.29.el7.1.aarch64 on an aarch64

localhost login:

Finally, once we’re done playing around with the image, there’s a slight bit of extra work required to remove it. Because the aarch64 images have an nvram specification we need to be sure to pass that information on to virsh, otherwise the undefine command will fail with an nvram error. The command example below shows how to delete the vm, including the disk image.


[root@aarch64 ~]# virsh undefine centos-7-aarch64 --remove-all-storage --nvram
Domain centos-7-aarch64 has been undefined
Volume 'vda'(/var/lib/libvirt/images/centos-7-aarch64.qcow2) removed.

 

That’s all there is to it. From here, you can use virsh or any of the other vm management tooling as you ordinarily would. The dark days of manually specifying AAVMF loader locations are behind us, as libvirt handles it all with ease now.

Testing your software project is important. Effectively communicating your test results to those that consume your project comes in a close second. Recently we enabled the Embeddable Build Status plugin in https://ci.centos.org which provides Pass/Fail images for the latest build of each job in CICO. These badges are perfect for inclusion in upstream webpages, and in Github README files.

To view a list of links and a short explanation of options related to a particular job, visit the ‘Embeddable Build Status’ link in the sidebar of each job page:

ebs_link

Embedding Badges in a Webpage

Since the badges are simply links to images, they can be pasted directly in <img>
tags on a blog or webpage. For the CentOS 7 t_functional nightly runs, a badge on a webpage with a link back to the project page would look something like this:

<a href="https://ci.centos.org/job/CentOS-Core-QA-t_functional-c7-64/"><img src="https://ci.centos.org/buildStatus/icon?job=CentOS-Core-QA-t_functional-c7-64" /></a>

Embedding Badges on Github

Including a badge in a Github README is as simple as using the Markdown link instead of the Plain link. For the same job above:

[![Build Status](https://ci.centos.org/buildStatus/icon?job=CentOS-Core-QA-t_functional-c7-64)](https://ci.centos.org/job/CentOS-Core-QA-t_functional-c7-64/)

To see what this looks like in action, visit the README in the t_functional repository on Github: https://github.com/CentOS/sig-core-t_functional
t_functional_status

To join the public CI effort and report the status of your jobs, say hello: ci [at] centos.org

Official Vagrant images for CentOS Linux 6 and CentOS Linux 7 for x86_64 are now available for download, featuring updated packages to 1st June 2016 and some improvements:

  • The size of the boot partition was increased to 250 MB for CentOS Linux 6 and 500 MB for CentOS Linux 7, as the Red Hat documentation recommends (this should prevent the system becoming impossible to update due to lack of space in /boot)
  • systemd will create a new machine id on first boot, making it possible to address multiple instances, all created from the official Vagrant image, in the same network (only for CentOS 7)
  • on CentOS Linux 6, tuned is preinstalled and it will use the virt-guest profile to improve performance (this was already the case on CentOS 7)
  • yum’s infra variable is set to vag, to offer CentOS developers some insight into how many installations are Vagrant instances

Known issues

  • The Vagrant sync folder is /home/vagrant/sync instead of /vagrant (which is the Vagrant default). The plan is to create link between the two locations in the next release, and only leave /vagrant in place in the release after the next.
  • Instances should always use NTP, but the official images don’t enable any NTP daemon (yet)
  • The VirtualBox Guest Additions are not preinstalled, and there are currently no plans of adding them. They are only needed for shared folders; host-only networking and forwarded ports work, although Vagrant displays a warning to the contrary. If you need the VirtualBox Guest Additions and would like to install them automatically, take a look at https://github.com/lpancescu/cloud-instance-starter-kit (pull requests are welcome).

Downloads

Only x86_64 images are currently available, for Vagrant’s libvirt and VirtualBox providers.

First-time users can download the official images from Hashicorp’s Atlas. You can use vagrant box add centos/6 for CentOS Linux 6, or vagrant box add centos/7 for CentOS Linux 7.

Existing users can upgrade their boxes directly by Vagrant, e.g. vagrant box update --box centos/7, but the changes will only apply to newly created instances.

Feedback

If you have any questions or problems with the Vagrant images, feel free to ask on the centos-devel mailing list, or in #centos-devel on Freenode.