nixpkgs/nixos/modules/installer/tools/nixos-checkout.nix
Eelco Dolstra 29027fd1e1 Rewrite ‘with pkgs.lib’ -> ‘with lib’
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
2014-04-14 16:26:48 +02:00

50 lines
1.2 KiB
Nix

# This module generates the nixos-checkout script, which replaces the
# Nixpkgs source trees in /etc/nixos/nixpkgs with a Git checkout.
{ config, lib, pkgs, ... }:
with lib;
let
nixosCheckout = pkgs.substituteAll {
name = "nixos-checkout";
dir = "bin";
isExecutable = true;
src = pkgs.writeScript "nixos-checkout"
''
#! ${pkgs.stdenv.shell} -e
if [ "$1" == "-h" ] || [ "$1" == "--help" ]; then
echo "Usage: `basename $0` [PREFIX]. See NixOS Manual for more info."
exit 0
fi
prefix="$1"
if [ -z "$prefix" ]; then prefix=/etc/nixos; fi
mkdir -p "$prefix"
cd "$prefix"
if [ -z "$(type -P git)" ]; then
echo "installing Git..."
nix-env -iA nixos.pkgs.git || nix-env -i git
fi
# Move any old nixpkgs directories out of the way.
backupTimestamp=$(date "+%Y%m%d%H%M%S")
if [ -e nixpkgs -a ! -e nixpkgs/.git ]; then
mv nixpkgs nixpkgs-$backupTimestamp
fi
# Check out the NixOS and Nixpkgs sources.
git clone git://github.com/NixOS/nixpkgs.git nixpkgs
'';
};
in
{
environment.systemPackages = [ nixosCheckout ];
}