OVH Guide

CoreOS is Linux for Massive Server Deployments. It leverages state of the art software like Docker and systemd to become the cluster operating system.

It supports painless upgrade, service discovery, overlay networks, Ceph, ... In a word, it's awesome!

And deploying it on Runabove is a breeze.

1. Create a custom VM template

Go the OpenStack Horizon, then go to Images panel and then on the create image button to install the new image.

CoreOS distributes official OpenStack compressed images that we'll need to prepare. For example:

wget http://alpha.release.core-os.net/amd64-usr/current/coreos_production_openstack_image.img.bz2
bunzip2 coreos_production_openstack_image.img.bz2

You can then upload resulting coreos_production_openstack_image.img file (around 400MB). Alternatively You'll find an already inflated images of CoreOS 431 here.

2. Launch an instance from this image

Click the Launch button right next to your new image.

Pick a cool name for your instance. Say agent_007. Make sure to select a network like Ext-Net. Then move on to the post-creation tab.

3. Configure your instance

If you don't have one already, generate a unique token to identify your new CoreOS cluster. This token will allow cluster members to automatically discover their peers.

curl https://discovery.etcd.io/new; echo

Paste and customize the following cloud-config script. Cloud-config is the standard for VM customization and especially well integrated by CoreOS team.

#cloud-config
coreos:
  etcd:
    # <token> as generated above
    discovery: https://discovery.etcd.io/<token>
    addr: $private_ipv4:4001
    peer-addr: $private_ipv4:7001
  units:
    - name: etcd.service
      command: start
    - name: fleet.service
      command: start

Launch... And voilà !

Don't forget to login with the user core instead of admin or root!

You can find more information: https://coreos.com/docs/running-coreos/platforms/openstack/