At the time of this writing, OVH is not providing a CoreOS installation template for the Kimsufi servers. Since there is no virtual KVM console available for the entry level servers, I tried to use OVH’s iPXE API. This approach would have worked well weren’t it for the CoreOS installer which tries to load binaries in the installation script after overwriting the same partition – which always results in a segfault. Also, the API is only available for the older Kimsufi 2G servers on OVH’s V6 control panel, not for the current Kimsufi servers for which OVH doesn’t provide an API at this time. Fortunately, OVH provides a “rescue mode” which lets us boot from an USB stick which is permanentely plugged in on all Kimsufi servers.
Step 1 – Boot the server in rescue mode
The first step ist to log in to the Kimsufi control panel and boot the server in rescue mode. You will receive a temporary password in the email once the rescue mode boot has been completed.
Step 2 – Download the CoreOS installer
In your server’s rescue mode shell:
cd /tmp wget https://raw.githubusercontent.com/coreos/init/master/bin/coreos-install chmod +x coreos-install
Step 3 – Create the CoreOS cloud-config file
Sample cloud-config is provided below. You will have to provide your own password hash and/or ssh key. The hash can be created using mkpasswd:
$ mkpasswd --method=SHA-512 --rounds=4096
You will also have to provide a unique token for your new CoreOS cluster. You can get your own token here:
If you plan to use your server’s public IP address in CoreOS shell scripts, you have to replace it as well.
#cloud-config hostname: coreos-1 users: - name: jan passwd: $6$rounds=4096$EqA.upwNw9abOwLz$M1kJkcibayX3Uuax8lZkaVsVfj4D150.7VV.ijf1YmoSCvNLZrtanuYuSleO6LuXkeFDMKr3gKz.hsCIobDvH0 groups: - sudo - docker coreos: etcd: discovery: https://discovery.etcd.io/02ae4bdcbe6a5x2838a42bb11e213ae5 units: - name: etcd.service command: start - name: fleet.service command: start write_files: - path: /etc/environment permissions: 0644 content: | PUBLIC_IPV4=220.127.116.11 ssh_authorized_keys: - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDEmGH8XzonmbJiF1W70mYIHE/ja8PRkysPpDKvlV6rM+fmQxvVjyxF9N/MxWmYI7XFUvwbBjosXyBrET9cUqr/GlB9J9XeNxrFg/9oDugVZg3aPDA7ekKYzXC156wMarPXdZTAHJt4lBaVmmDcxnInsfOk5WFjn91gYw6TXIZW0LMaxEbLf0gYWbXPC0unRn1S15OV6dtzaLciO1WhPWeoG0f/23UEpVI7Z5GU4D6QOx1vr6V/NoHgx93PAZkMofB7IM3Uxo24Gqo0pQP8lSVTxlnU27OqaG78hI4gSbys621DD81EM6uasuOU8USl1EIdfQaJDUFJvs6AMLWFdazj core
Tip: Do not use tabs in YAML. You could always validate your cloud-config file using a YAML validator.
Step 4 – Run the CoreOS installer
I’m using the beta release channel in the sample below. You could also specify the alpha or stable channel.
./coreos-install -d /dev/sda -c ./cloud-config.yaml -C beta Downloading the signature for http://beta.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2... 2014-09-27 14:44:47 URL:http://beta.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2.sig [543/543] -> "/tmp/coreos-install.UbWzYE5v8T/coreos_production_image.bin.bz2.sig"  Downloading, writing and verifying coreos_production_image.bin.bz2... 2014-09-24 14:46:17 URL:http://beta.release.core-os.net/amd64-usr/current/coreos_production_image.bin.bz2 [181295789/181295789] -> "-"  gpg: Signature made Fri Sep 26 08:00:47 2014 CEST using RSA key ID E5676EFC gpg: key 93D2DCB4 marked as ultimately trusted gpg: checking the trustdb gpg: 3 marginal(s) needed, 1 complete(s) needed, PGP trust model gpg: depth: 0 valid: 1 signed: 0 trust: 0-, 0q, 0n, 0m, 0f, 1u gpg: Good signature from "CoreOS Buildbot (Offical Builds) <email@example.com>" Installing cloud-config... Success! CoreOS beta current is installed on /dev/sda
Step 5 – Reboot
Back in OVH’s control panel, turn off rescue mode boot by selecting hard disk boot and restart the server. After a couple of minutes you should be able to ssh into your new CoreOS server either by providing the username/password combination from the cloud-config file or just by using the specified ssh key and the CoreOS default user “core”.
This is it! Where to go from here? There’s a lot of documentation on how to set up etcd/fleet for your new CoreOS server. A very handy command after setting up a new CoreOS server is “toolbox”.