Bootstrap script for NixOS Rackspace

nixos-install-rackspace.sh

#!/usr/bin/env bash
unset CDPATH

DISK=/dev/xvdb
PARTITION=/dev/xvdb1
FSTYPE=ext4
LABEL=nixos

## -----------------------------------------------------------------------------
## -- NixOS configuration template

NIXCFG=$(cat <<EOF
{ config, pkgs, ... }:

{
  imports = [ ./hardware-configuration.nix ];

  boot.loader.grub.enable  = true;
  boot.loader.grub.version = 2;
  boot.loader.grub.device  = "$DISK";
  time.timeZone = "America/Chicago";
  networking.hostName = "nixos"; # Define your hostname.

  networking.interfaces.eth0.ipAddress    = "IPV4ADDR1";
  networking.interfaces.eth0.prefixLength = 24;

  networking.interfaces.eth1.ipAddress    = "IPV4ADDR2";
  networking.interfaces.eth1.prefixLength = 19;

  networking.defaultGateway  = "GATEWAY";
  networking.nameservers     = [ "NAMESERVER1" "NAMESERVER2" ];

  i18n = {
    consoleFont = "lat9w-16";
    consoleKeyMap = "us";
    defaultLocale = "en_US.UTF-8";
  };

  environment.systemPackages = with pkgs; [
    wget
  ];

  services.openssh.enable = true;

  security.sudo.wheelNeedsPassword = false;
  users.extraUsers.root.openssh.authorizedKeys.keys = [
    "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAACAQDKN53e1R17ha560eN3TJ/uV63vgppBVOGB2bZ5H7AnvVdrV6ZnrRU0LY9VBx0bF5q2+Hst8X9xOuTKLg38XFLkSWjI0Bxt4qYbwRr8RyafI8n0UUV/sLFPEkVw2Y2jUlMxGhPUtCXZbB8V2n8Zcn/QESnUKOzZHGh2VuQ1ydra58gCK6jDot51lNh4oT0WL3F+KY7cKGv5uyDLtaGxxiPYBRZvhBLjdPAYfkTa1NOAYoN3wPfFtH4xuCP2nTSbodAgQ/UsY/aNdNkK97//GZzT5h7cA4G+//b5tNaGCN0j7RJ6wSGFCut3QvKiYlsU0sAuwyYhizuo/+IoWV2LT2W6pHRe5Ivodyzm97bkWzI+UzGKLP5VKH55Pol4iIhnavhUP5j4IIr5Xplbvp+BdVVgfaSWpRH0t4ALyn1oDZZNUkzjwFbw/EPkdndJjChziEPO31koPBFcm/IB7DvXYjPrTY9S5nlF7QbA2A3118oem4V9A4FNi9gijFJspkHPFJ2CzFoYbCg9fCwPkeS/poS6ZgBL0p4sMoqxj+2OUdS6Vg8IO143YIUmA7FcFYafhhpTWSD44lja7a8RkDcukOA2YdcuMf5f10xbW3auZ3Gjatj1Jp0hTqIT78FaEBoZJnSmJSwi/hyMWV/vix+SCw3BPwjIJ/xQUccpNwh++E/Zdw== a@link"
  ];
}
EOF
)

## -----------------------------------------------------------------------------
## -- Basic functions

function good { echo "[+]" $1; }
function onoes { echo "[-]" $1; }
function info { echo "[!]" $1; }

## -----------------------------------------------------------------------------
## -- Setup steps

function setup_tools {
  good "Installing needed packages and temporary users..."

  (apt-get update && \
    apt-get install bzip2 && \
    addgroup nixbld && \
    ((echo; echo; echo; echo; echo; echo) | adduser --disabled-password nixbld0) && \
    usermod -a -G nixbld nixbld0) >/dev/null 2>&1
}

function partition_disk { # (partition)
  good "Formatting disk ($1)..."

  (echo d; echo w;)                        | fdisk $1 >/dev/null 2>&1
  (echo n; echo; echo; echo; echo; echo w) | fdisk $1 >/dev/null 2>&1
}

function format_disk { # (fstype, partition, label)
  good "Formatting '$2' as $1 (name='$3')"

  mkfs.$1 $2 -L $3  >/dev/null 2>&1
  mount $2 /mnt     >/dev/null 2>&1
  mkdir /mnt/boot   >/dev/null 2>&1
}

function install_nixpkgs {
  good "Installing nixpkgs..."

  curl -s -o install-nix.sh https://nixos.org/nix/install >/dev/null 2>&1
  bash ./install-nix.sh                                   >/dev/null 2>&1
  rm -f ./install-nix.sh
}

function update_nixpkgs {
  good "Updating channels..."

  . /root/.nix-profile/etc/profile.d/nix.sh  >/dev/null 2>&1
  nix-channel --remove nixpkgs               >/dev/null 2>&1
  nix-channel --add http://nixos.org/channels/nixos-unstable nixos >/dev/null 2>&1
  nix-channel --update >/dev/null 2>&1
}

function bootstrap_nixos_tools {
  good "Installing NixOS utilities..."

  cat <<EOF > configuration.nix
{ fileSystems."/" = {};
  boot.loader.grub.enable = false;
}
EOF

  export NIX_PATH=nixpkgs=/root/.nix-defexpr/channels/nixos:nixos=/root/.nix-defexpr/channels/nixos/nixos
  export NIXOS_CONFIG=/root/configuration.nix
  nix-env -i -A config.system.build.nixos-install \
             -A config.system.build.nixos-option  \
             -A config.system.build.nixos-generate-config \
          -f "<nixos>" >/dev/null 2>&1
}

function generate_nixos_conf {
  good "Generating template installation..."

  nixos-generate-config --root /mnt >/dev/null 2>&1
  echo "$NIXCFG" > /mnt/etc/nixos/configuration.nix

  # Now, substitute in values for the networking configuration.
  GATEWAY=$(grep gateway /etc/network/interfaces | awk '{print $2}' | head -1)
  NS1=$(grep nameserver /etc/resolv.conf | awk '{print $2}' | head -1)
  NS2=$(grep nameserver /etc/resolv.conf | awk '{print $2}' | tail -1)

  perl -pi -e "s/GATEWAY/$GATEWAY/" /mnt/etc/nixos/configuration.nix
  perl -pi -e "s/NAMESERVER1/$NS1/" /mnt/etc/nixos/configuration.nix
  perl -pi -e "s/NAMESERVER2/$NS2/" /mnt/etc/nixos/configuration.nix

  # IPv4 public network interface:
  PUBIPV4=$(grep address /etc/network/interfaces | awk '{print $2}' | head -1)
  perl -pi -e "s/IPV4ADDR1/$PUBIPV4/" /mnt/etc/nixos/configuration.nix

  # IPv4 private network interface:
  PRIVIPV4=$(grep address /etc/network/interfaces | awk '{print $2}' | tail -1)
  perl -pi -e "s/IPV4ADDR2/$PRIVIPV4/" /mnt/etc/nixos/configuration.nix
}

function install_nixos {
  good "Installing NixOS..."

  unset NIXOS_CONFIG
  nixos-install >/dev/null 2>&1

  # Now, substitute *back* the right name for post-reboot
  perl -pi -e "s#$DISK#/dev/xvda#" /mnt/etc/nixos/configuration.nix
}

## -----------------------------------------------------------------------------
## -- Main program

cd /root

setup_tools

partition_disk $DISK

format_disk $FSTYPE $PARTITION $LABEL

install_nixpkgs

update_nixpkgs

bootstrap_nixos_tools

generate_nixos_conf

install_nixos

good "OK, all done. You can now reboot."