1. Get some VMs

What I want?

So, I need some VMs.

In the current infrastructure, I have:

  • 1 VM for the bastion
    • it’s the only machine with an SSH access to the Internet
    • it has also a DNS server
    • of course, it runs OpenBSD
  • 3 VMs as the core
    • they host the Consul Servers and the Nomad Servers
    • of course, they run OpenBSD
  • 3 VMs acting as working nodes
    • they run the services, as Docker containers
    • they are Consul Clients and Nomad Clients
    • they are powered by Debian (for Docker containers)
  • 2 VMs acting as edge nodes
    • they handle the incoming Web traffic
    • of course, they run OpenBSD


I simply ordered the VMs from the OVH Public Cloud offer, using the UI:

  • I took the Debian distribution for all of them
  • s1-2 instances are doing well

Of course, all this work (and the next chapter) could have been done with Ansible, Terraform and some Packer’s templates VMs stored on OVH’s Openstack.
I’ll probably do it in a future attempt.

System installation

For the VMs with Debian: no problem, as they are totally supported.


But OVH Public Cloud does not support OpenBSD directly.

Solution to install OpenBSD

We have to install OpenBSD manually!

Prepare the conversion to OpenBSD

Connect to the VMs that need to be reinstalled to OpenBSD with the SSH key you put on the OVH console and with the debian user:

ssh -i ~/.ssh/ovh_provisioning debian@<ip>

Then as root, download the ramdisk kernel.

sudo -u root -i
cd / && wget https://ftp.fr.openbsd.org/pub/OpenBSD/6.7/amd64/bsd.rd

We will reboot the machine and ask Grub to boot on the ramdisk kernel.

So before rebooting, edit the Grub menu in /etc/grub.d/40_custom:

menuentry "OpenBSD" {
       set root=(hd0,msdos1)
       kopenbsd /bsd.rd

And add some timeout by editing /etc/default/grub:


Don’t forget to update the microcode and then reboot:


Convert to OpenBSD

Go to the OVH console and access each VM’s VNC console: you can now install OpenBSD as usual

For the paritioning, here is mine:

sd0> p m
OpenBSD area: 128-20970240; size: 10239.3M; free: 0.0M
#                size           offset  fstype [fsize bsize   cpg]
  a:          1024.3M              128  4.2BSD   2048 16384 12960 # /
  b:           256.2M          2097920    swap                    # none
  c:         10240.0M                0  unused                    
  d:          1024.4M          2622720  4.2BSD   2048 16384 12960 # /tmp
  e:          3072.5M          4720640  4.2BSD   2048 16384 12960 # /usr
  f:          4861.9M         11013120  4.2BSD   2048 16384 12947 # /var


Create a private network

In the OVH console, put all VMs in a private network: this will allow to configure the secondary interface.


You could already create a second private network: it will be used for the carp communication between the edge nodes.

Configure the VMs

Problems with DHCP and OpenBSD

I experienced some issues with OpenBSD and DHCP, so I will configure everything as static.


On both Debian and OpenBSD hosts, configure the network interfaces as static interfaces:

On OpenBSD:

vi /etc/hostname.vio1
sh /etc/netstart vio1
vi /etc/hostname.vio0
sh /etc/netstart vio0

On Debian:

vi /etc/network/interfaces
systemctl restart networking