nixpkgs/nixos/modules/installer/cd-dvd/channel.nix
2013-10-28 22:45:57 +01:00

45 lines
1.5 KiB
Nix

# Provide an initial copy of the NixOS channel so that the user
# doesn't need to run "nix-channel --update" first.
{ config, pkgs, ... }:
with pkgs.lib;
let
# We need a copy of the Nix expressions for Nixpkgs and NixOS on the
# CD. These are installed into the "nixos" channel of the root
# user, as expected by nixos-rebuild/nixos-install.
channelSources = pkgs.runCommand "nixos-${config.system.nixosVersion}"
{ expr = builtins.readFile ../../../lib/channel-expr.nix; }
''
mkdir -p $out/nixos
cp -prd ${pkgs.path} $out/nixos/nixpkgs
ln -s nixpkgs/nixos $out/nixos/nixos
chmod -R u+w $out/nixos
rm -rf $out/nixos/nixpkgs/.git
echo -n ${config.system.nixosVersion} > $out/nixos/nixpkgs/.version
echo -n "" > $out/nixos/nixpkgs/.version-suffix
echo "$expr" > $out/nixos/default.nix
'';
in
{
# Provide the NixOS/Nixpkgs sources in /etc/nixos. This is required
# for nixos-install.
boot.postBootCommands =
''
if ! [ -e /var/lib/nixos/did-channel-init ]; then
echo "unpacking the NixOS/Nixpkgs sources..."
mkdir -p /nix/var/nix/profiles/per-user/root
${config.nix.package}/bin/nix-env -p /nix/var/nix/profiles/per-user/root/channels \
-i ${channelSources} --quiet --option use-substitutes false
mkdir -m 0700 -p /root/.nix-defexpr
ln -s /nix/var/nix/profiles/per-user/root/channels /root/.nix-defexpr/channels
mkdir -m 0755 -p /var/lib/nixos
touch /var/lib/nixos/did-channel-init
fi
'';
}