stage2

#!/bin/sh

set -eu

root_mount=$1
root_type=$2
grub_device=$3
digitalocean=$4
digitalocean_configs=""

if [ "$digitalocean" = "true" ];
then
  digitalocean_configs="
    ## Digital Ocean networking setup; manage interfaces manually
    networking.useDHCP = false;

    systemd.services.setup-network = {
      wantedBy = [ \"multi-user.target\" ];
      after = [ \"network-pre.target\" ];
      path = [ pkgs.gawk pkgs.iproute pkgs.openresolv ];
      serviceConfig = {
        ExecStart = \"\${pkgs.bash}/bin/bash /etc/nixos-in-place/setup-network\";
      };
    };
  "
  mkdir -p /nixos/etc/nixos-in-place
  cp /nixos-in-place/setup-network /nixos/etc/nixos-in-place/

  ## Not a valid link now, but this will represent the file which DO will
  ## update each boot.
  mkdir -p /nixos/etc/network
  ln -sf /old-root/etc/network/interfaces /nixos/etc/network/

  ## Use the original authorized_keys that DO added
  mkdir -pm 711 /root/
  mkdir -pm 700 /root/.ssh/
  ln -sf /old-root/root/.ssh/authorized_keys /root/.ssh/authorized_keys
fi

## Enable host resolution
cp /etc/external-resolv.conf /etc/resolv.conf

## Install dependencies; it's easier to do this here, in the Nix chroot,
## since we don't rely on the host system.
nix-env -i pcre

## Generate a base config
nixos-generate-config --root /nixos

cat <<EOF > /nixos/etc/nixos/nixos-in-place.nix
{ config, pkgs, ... }:
{
  ## You probably want to change or remove these settings.
  $(cat /nixos/extra-config)

  ## You probably do NOT want to change these settings.
  boot.kernelParams = ["boot.shell_on_fail"];
  boot.loader.grub.device = "$grub_device";
  boot.loader.grub.storePath = "/nixos/nix/store";
  boot.initrd.supportedFilesystems = [ "$root_type" ];
  boot.initrd.postDeviceCommands = ''
    mkdir -p /mnt-root/old-root ;
    mount -t $root_type $root_mount /mnt-root/old-root ;
  '';
  fileSystems = {
    "/" = {
      device = "/old-root/nixos";
      fsType = "none";
      options = [ "bind" ];
    };
    "/old-root" = {
      device = "$root_mount";
      fsType = "$root_type";
    };
  };

  ## These settings are specified to DigitalOcean.
  $digitalocean_configs
}
EOF

## Add in our configuration additions
nixos_dir=/nixos/etc/nixos
cp $nixos_dir/configuration.nix $nixos_dir/backup-configuration.nix
sed -i 's|\(\s*\)\(./hardware-configuration.nix\)|\1\2\n\1./nixos-in-place.nix|' $nixos_dir/configuration.nix

## Enable SSH by default
sed -i 's/# \(services\.openssh\)/\1/' $nixos_dir/configuration.nix

## Remove the automatically-generated fileSystems configuration
mv $nixos_dir/hardware-configuration.nix $nixos_dir/backup-hardware-configuration.nix
pcregrep -Mv "fileSystems.\"/\"[\s\S]*};" $nixos_dir/backup-hardware-configuration.nix > $nixos_dir/hardware-configuration.nix

## Installs grub and a base NixOS system; after a reboot, we're golden
NIXOS_INSTALL_REEXEC=1 nixos-install --root /nixos --show-trace --no-root-passwd
exit