commit efad915fcd70878e76627a59423b6afc4e372813 Author: Illia Chub Date: Mon Dec 7 11:09:48 2020 +0200 Initial commit diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..94a9ed0 --- /dev/null +++ b/LICENSE @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. 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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/README.md b/README.md new file mode 100644 index 0000000..cf9eef3 --- /dev/null +++ b/README.md @@ -0,0 +1,104 @@ +This script aims to install NixOS on Digital Ocean droplets, Vultr servers, or +OVH Virtual Private Servers (starting from distros that these services support +out of the box). + +## Source Distros + +This script has been tested and can install NixOS from the following source distros: + +On Digital Ocean: +- Fedora 24 x64 +- Ubuntu 20.04 x64 + +On Vultr: +- Ubuntu 18.10 x64 + +On OVH Virtual Private Servers (experimental): +- Debian + +On Hetzner cloud: +- Ubuntu 18.04 + +YMMV with any other hoster + image combination. + +If you have a OpenVZ based virtualization solution then this, or any other OS takeover script will not work, this is fundamental to how OpenVZ works. + +## Considerations + +nixos-infect is so named because of the high likelihood of rendering a system +inoperable. Use with caution and preferably only on newly-provisioned +systems. + +*WARNING NB*: This script wipes out the targeted host's root filesystem when it +runs to completion. Any errors halt execution. It's advised to run with +`bash -x` to help debug, as often a failed run leaves the system in an +inconsistent state, requiring a rebuild (in DigitalOcean panel: Droplet +Settings -> "Destroy" -> "Rebuild from original"). + +## Digital Ocean + +*TO USE:* +- Add any custom config you want (see notes below) +- Deploy the droplet indicated at the top of the file, enable ipv6, add your ssh key +- `cat customConfig.optional nixos-infect | ssh root@targethost` + +Alternatively, you may utilize Digital Ocean's "user data" mechanism (found in the Web UI or HTTP API), and supply to it the following example yaml stanzas: + +```yaml +#cloud-config + +runcmd: + - curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | PROVIDER=digitalocean NIX_CHANNEL=nixos-20.03 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. + +```yaml +#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-20.03 bash 2>&1 | tee /tmp/infect.log + +``` + +## Vultr + +To set up a NixOS Vultr server, instantiate an Ubuntu box with the following "Startup Script": + +```bash +#!/bin/sh + +curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-20.03 bash +``` + +Allow for a few minutes over the usual Ubuntu deployment time for NixOS to download & install itself. + +## Hetzner cloud + +Hetzner cloud works out of the box. When creating a server provide the following script as "User data" (this has been tested using Ubuntu 20.04 as a base OS). + +``` +#!/bin/sh + +curl https://raw.githubusercontent.com/elitak/nixos-infect/master/nixos-infect | NIX_CHANNEL=nixos-20.03 bash 2>&1 | tee /tmp/infect.log +``` + +## 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) diff --git a/nixos-infect b/nixos-infect new file mode 100755 index 0000000..f61652d --- /dev/null +++ b/nixos-infect @@ -0,0 +1,270 @@ +#! /usr/bin/env bash + +# More info at: https://github.com/elitak/nixos-infect + +set -e -o pipefail + +makeConf() { + # Skip everything if main config already present + [[ -e /etc/nixos/configuration.nix ]] && return 0 + # NB <<"EOF" quotes / $ ` in heredocs, < /etc/nixos/configuration.nix << EOF +{ ... }: { + imports = [ + ./hardware-configuration.nix + $network_import + $NIXOS_IMPORT + ]; + + boot.cleanTmpDir = true; + networking.hostName = "$(hostname)"; + networking.firewall.allowPing = true; + services.openssh.enable = true; + users.users.root.openssh.authorizedKeys.keys = [$(while read -r line; do echo -n " + \"$line\" "; done <<< "$keys") + ]; +} +EOF + # If you rerun this later, be sure to prune the filesSystems attr + cat > /etc/nixos/hardware-configuration.nix << EOF +{ ... }: +{ + imports = [ ]; + boot.loader.grub.device = "$grubdev"; + fileSystems."/" = { device = "$rootfsdev"; fsType = "ext4"; }; +} +EOF + + [[ -n "$doNetConf" ]] && makeNetworkingConf +} + +makeNetworkingConf() { + # XXX It'd be better if we used procfs for all this... + local IFS=$'\n' + eth0_name=$(ip address show | grep '^2:' | awk -F': ' '{print $2}') + eth0_ip4s=$(ip address show dev "$eth0_name" | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|') + eth0_ip6s=$(ip address show dev "$eth0_name" | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || '') + gateway=$(ip route show dev "$eth0_name" | grep default | sed -r 's|default via ([0-9.]+).*|\1|') + gateway6=$(ip -6 route show dev "$eth0_name" | grep default | sed -r 's|default via ([0-9a-f:]+).*|\1|' || true) + ether0=$(ip address show dev "$eth0_name" | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|') + + eth1_name=$(ip address show | grep '^3:' | awk -F': ' '{print $2}')||true + if [ -n "$eth1_name" ];then + eth1_ip4s=$(ip address show dev "$eth1_name" | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|') + eth1_ip6s=$(ip address show dev "$eth1_name" | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || '') + ether1=$(ip address show dev "$eth1_name" | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|') + interfaces1=<< EOF + $eth1_name = { + ipv4.addresses = [$(for a in "${eth1_ip4s[@]}"; do echo -n " + $a"; done) + ]; + ipv6.addresses = [$(for a in "${eth1_ip6s[@]}"; do echo -n " + $a"; done) + ]; +EOF + extraRules1="ATTR{address}==\"${ether1}\", NAME=\"${eth1_name}\"" + else + interfaces1="" + extraRules1="" + fi + + readarray nameservers < <(grep ^nameserver /etc/resolv.conf | sed -r 's/^nameserver[[:space:]]+([0-9.a-fA-F]+).*/"\1"/') + + if [[ "$eth0_name" = eth* ]]; then + predictable_inames="usePredictableInterfaceNames = lib.mkForce false;" + else + predictable_inames="usePredictableInterfaceNames = lib.mkForce true;" + fi + cat > /etc/nixos/networking.nix << EOF +{ lib, ... }: { + # This file was populated at runtime with the networking + # details gathered from the active system. + networking = { + nameservers = [ ${nameservers[@]} ]; + defaultGateway = "${gateway}"; + defaultGateway6 = "${gateway6}"; + dhcpcd.enable = false; + $predictable_inames + interfaces = { + $eth0_name = { + ipv4.addresses = [$(for a in "${eth0_ip4s[@]}"; do echo -n " + $a"; done) + ]; + ipv6.addresses = [$(for a in "${eth0_ip6s[@]}"; do echo -n " + $a"; done) + ]; + ipv4.routes = [ { address = "${gateway}"; prefixLength = 32; } ]; + ipv6.routes = [ { address = "${gateway6}"; prefixLength = 32; } ]; + }; + $interfaces1 + }; + }; + services.udev.extraRules = '' + ATTR{address}=="${ether0}", NAME="${eth0_name}" + $extraRules1 + ''; +} +EOF +} + +makeSwap() { + # TODO check currently available swapspace first + swapFile=$(mktemp /tmp/nixos-infect.XXXXX.swp) + dd if=/dev/zero "of=$swapFile" bs=1M count=$((1*1024)) + chmod 0600 "$swapFile" + mkswap "$swapFile" + swapon -v "$swapFile" +} + +removeSwap() { + swapoff -a + rm -vf /tmp/nixos-infect.*.swp +} + +prepareEnv() { + # $grubdev is used in makeConf() + for grubdev in /dev/vda /dev/sda; do [[ -e $grubdev ]] && break; done + + # Retrieve root fs block device + # (get root mount) (get partition or logical volume) + rootfsdev=$(mount | grep "on / type" | awk '{print $1;}') + + # DigitalOcean doesn't seem to set USER while running user data + export USER="root" + export HOME="/root" + + # Nix installer tries to use sudo regardless of whether we're already uid 0 + #which sudo || { sudo() { eval "$@"; }; export -f sudo; } + # shellcheck disable=SC2174 + mkdir -p -m 0755 /nix +} + +fakeCurlUsingWget() { + # Use adapted wget if curl is missing + which wget && { \ + curl() { + eval "wget $( + (local isStdout=1 + for arg in "$@"; do + case "$arg" in + "-o") + echo "-O"; + isStdout=0 + ;; + "-O") + isStdout=0 + ;; + "-L") + ;; + *) + echo "$arg" + ;; + esac + done; + [[ $isStdout -eq 1 ]] && echo "-O-" + )| tr '\n' ' ' + )" + }; export -f curl; } +} + +req() { + type "$1" > /dev/null 2>&1 || which "$1" > /dev/null 2>&1 +} + +checkEnv() { + # Perform some easy fixups before checking + # TODO prevent multiple calls to apt-get update + which dnf && dnf install -y perl-Digest-SHA # Fedora 24 + which bzcat || (which yum && yum install -y bzip2) \ + || (which apt-get && apt-get update && apt-get install -y bzip2) \ + || true + which xzcat || (which yum && yum install -y xz-utils) \ + || (which apt-get && apt-get update && apt-get install -y xz-utils) \ + || true + which curl || fakeCurlUsingWget \ + || (which apt-get && apt-get update && apt-get install -y curl) \ + || true + + [[ "$(whoami)" == "root" ]] || { echo "ERROR: Must run as root"; return 1; } + + req curl || req wget || { echo "ERROR: Missing both curl and wget"; return 1; } + req bzcat || { echo "ERROR: Missing bzcat"; return 1; } + req xzcat || { echo "ERROR: Missing xzcat"; return 1; } + req groupadd || { echo "ERROR: Missing groupadd"; return 1; } + req useradd || { echo "ERROR: Missing useradd"; return 1; } + req ip || { echo "ERROR: Missing ip"; return 1; } + req awk || { echo "ERROR: Missing awk"; return 1; } + req cut || { echo "ERROR: Missing cut"; return 1; } +} + +infect() { + # Add nix build users + # FIXME run only if necessary, rather than defaulting true + groupadd nixbld -g 30000 || true + for i in {1..10}; do + useradd -c "Nix build user $i" -d /var/empty -g nixbld -G nixbld -M -N -r -s "$(which nologin)" "nixbld$i" || true + done + # TODO use addgroup and adduser as fallbacks + #addgroup nixbld -g 30000 || true + #for i in {1..10}; do adduser -DH -G nixbld nixbld$i || true; done + + curl -L https://nixos.org/nix/install | $SHELL + + # shellcheck disable=SC1090 + source ~/.nix-profile/etc/profile.d/nix.sh + + [[ -z "$NIX_CHANNEL" ]] && NIX_CHANNEL="nixos-19.09" + nix-channel --remove nixpkgs + nix-channel --add "https://nixos.org/channels/$NIX_CHANNEL" nixos + nix-channel --update + + export NIXOS_CONFIG=/etc/nixos/configuration.nix + + nix-env --set \ + -I nixpkgs=$HOME/.nix-defexpr/channels/nixos \ + -f '' \ + -p /nix/var/nix/profiles/system \ + -A system + + # Remove nix installed with curl | bash + rm -fv /nix/var/nix/profiles/default* + /nix/var/nix/profiles/system/sw/bin/nix-collect-garbage + + # Reify resolv.conf + [[ -L /etc/resolv.conf ]] && mv -v /etc/resolv.conf /etc/resolv.conf.lnk && cat /etc/resolv.conf.lnk > /etc/resolv.conf + + # Stage the Nix coup d'état + touch /etc/NIXOS + echo etc/nixos > /etc/NIXOS_LUSTRATE + echo etc/resolv.conf >> /etc/NIXOS_LUSTRATE + echo root/.nix-defexpr/channels >> /etc/NIXOS_LUSTRATE + + rm -rf /boot.bak + mv -v /boot /boot.bak + /nix/var/nix/profiles/system/bin/switch-to-configuration boot +} + +[ "$PROVIDER" = "digitalocean" ] && doNetConf=y # digitalocean requires detailed network config to be generated + + +prepareEnv +makeSwap # smallest (512MB) droplet needs extra memory! +checkEnv +makeConf +infect +removeSwap + +if [[ -z "$NO_REBOOT" ]]; then + reboot +fi