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

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