NixOS-Infect

What is this?

A script to install NixOS on non-NixOS hosts.

NixOS-Infect is so named because of the high likelihood of rendering a system inoperable. Use with extreme caution and preferably only on newly provisioned systems.

This script has successfully been tested on at least the follow hosting providers and plans:

• DigitalOcean
• Hetzner Cloud
• Vultr
• Interserver VPS
• Tencent Cloud Lighthouse
• OVHcloud

Should you find that it works on your hoster, feel free to update this README and issue a pull request.

NB: OpenVZ-based virtualization providers are known not to work with nixos-infect (or any other OS takeover script). This is core to how OpenVZ operates and cannot be resolved.

Motivation

Motivation for this script: nixos-assimilate should supplant this script entirely, if it's ever completed. nixos-in-place was quite broken when I tried it, and also took a pretty janky approach that was substantially more complex than this (although it supported more platforms): it didn't install to root (/nixos instead), left dregs of the old filesystem (almost always unnecessary since starting from a fresh deployment), and most importantly, simply didn't work for me! (old system was being because grub wasnt properly reinstalled)

How do I use it?

0. Read and understand the the script
1. Deploy any custom configuration you want on your host
2. Deploy your host as non-Nix Operating System.
3. Deploy an SSH key for the root user.

NB: This step is important. The root user will not have a password when nixos-infect runs to completion. To enable root login, you must have an SSH key configured.

4. run the script with:

  curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-20.09 bash -x

NB: This script wipes out the targeted host's root filesystem when it runs to completion. Any errors halt execution. A failure will leave the system in an inconsistent state, and so it is advised to run with bash -x.

Hoster notes:

Digital Ocean

You mmay utilize Digital Ocean's "user data" mechanism (found in the Web UI or HTTP API), and supply to it the following example yaml stanzas:

#cloud-config

runcmd:
  - curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | PROVIDER=digitalocean NIX_CHANNEL=nixos-20.09 bash 2>&1 | tee /tmp/infect.log

Potential tweaks:

• /etc/nixos/{,hardware-}configuration.nix: rudimentary mostly static config
• /etc/nixos/networking.nix: networking settings determined at runtime tweak if no ipv6, different number of adapters, etc.

#cloud-config
write_files:
- path: /etc/nixos/host.nix
  permissions: '0644'
  content: |
    {pkgs, ...}:
    {
      environment.systemPackages = with pkgs; [ vim ];
    }    
runcmd:
  - curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | PROVIDER=digitalocean NIXOS_IMPORT=./host.nix NIX_CHANNEL=nixos-20.09 bash 2>&1 | tee /tmp/infect.log

Tested on

Distribution	Name	Status	test date
CentOS	6.9 x32	failure	2020-03-30
CentOS	6.9 x64	failure	2020-03-30
CentOS	7.6 x64	failure	2020-03-30
CentOS	8.1 x64	success	2020-03-30
CoreOS	2345.3.0 (stable)	unable	2020-03-30
CoreOS	2411.1.0 (beta)	unable	2020-03-30
CoreOS	2430.0.0 (alpha)	unable	2020-03-30
Debian	10.3 x64	success	2020-03-30
Debian	9.12 x64	success	2020-03-30
Fedora	30 x64	success	2020-03-30
Fedora	31 x64	success	2020-03-30
FreeBSD	11.3 x64 ufs	failure	2020-03-30
FreeBSD	11.3 x64 zfs	failure	2020-03-30
FreeBSD	12.1 x64 ufs	failure	2020-03-30
FreeBSD	12.1 x64 zfs	failure	2020-03-30
RancherOS	v1.5.5	unable	2020-03-30
Ubuntu	16.04.6 (LTS) x32	success	2020-03-30
Ubuntu	16.04.6 (LTS) x64	success	2020-03-30
Ubuntu	18.04.3 (LTS) x64	success	2020-03-30
Ubuntu	19.10 x64	success	2020-03-30

Vultr

To set up a NixOS Vultr server, instantiate an Ubuntu box with the following "Startup Script":

#!/bin/sh

curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-20.09 bash

Allow for a few minutes over the usual Ubuntu deployment time for NixOS to download & install itself.

Tested on

Distribution	Name	Status	test date	Slug	ID
Ubuntu	18.10 x64	success	(Unknown)	(Unknown)	(Unknown)

Hetzner cloud

Hetzner cloud works out of the box. When creating a server provide the following script as "User data":

#!/bin/sh

curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-20.09 bash 2>&1 | tee /tmp/infect.log

Tested on

Distribution	Name	Status	test date
Ubuntu	20.04 x64	success	(Unknown)

InterServer VPS

Tested on

Distribution	Name	Status	test date
Debian	9	success	2021-01-29
Debian	10	success	2021-01-29
Ubuntu	20.04	success	2021-01-29
Ubuntu	18.04	success	2021-01-29
Ubuntu	14.04	success	2021-01-29

Tencent Cloud Lighthouse

Tencent Cloud Lighthouse Hong Kong Region Works out of the box.

Other Regions in China may not work because of the unreliable connection between China and global Internet or GFW.

Tested on

Distribution	Name	Status	test date
Debian	10	success	2021-03-11

OVHcloud

Before executing the install script, you may need to check your mounts with df -h. By default, OVH adds a relatively short in memory tmpfs mount on the /tmp folder, so the install script runs short in memory and fails. Just execute umount /tmp before launching the install script. Full install process described here

Distribution	Name	Status	test date
Arch Linux	Arch Linux x86-64	success	2021-03-25