pyrox.dev
1# Provide an initial copy of the NixOS channel so that the user
2# doesn't need to run "nix-channel --update" first.
3
4{
5 config,
6 lib,
7 pkgs,
8 ...
9}:
10
11let
12 # This is copied into the installer image, so it's important that it is filtered
13 # to avoid including a large .git directory.
14 # We also want the source name to be normalised to "source" to avoid depending on the
15 # location of nixpkgs.
16 # In the future we might want to expose the ISO image from the flake and use
17 # `self.outPath` directly instead.
18 nixpkgs = lib.cleanSource pkgs.path;
19
20 # We need a copy of the Nix expressions for Nixpkgs and NixOS on the
21 # CD. These are installed into the "nixos" channel of the root
22 # user, as expected by nixos-rebuild/nixos-install. FIXME: merge
23 # with make-channel.nix.
24 channelSources =
25 pkgs.runCommand "nixos-${config.system.nixos.version}" { preferLocalBuild = true; }
26 ''
27 mkdir -p $out
28 cp -prd ${nixpkgs.outPath} $out/nixos
29 chmod -R u+w $out/nixos
30 if [ ! -e $out/nixos/nixpkgs ]; then
31 ln -s . $out/nixos/nixpkgs
32 fi
33 ${lib.optionalString (config.system.nixos.revision != null) ''
34 echo -n ${config.system.nixos.revision} > $out/nixos/.git-revision
35 ''}
36 echo -n ${config.system.nixos.versionSuffix} > $out/nixos/.version-suffix
37 echo ${config.system.nixos.versionSuffix} | sed -e s/pre// > $out/nixos/svn-revision
38 '';
39in
40
41{
42 options.system.installer.channel.enable =
43 (lib.mkEnableOption "bundling NixOS/Nixpkgs channel in the installer")
44 // {
45 default = true;
46 };
47 config = lib.mkIf config.system.installer.channel.enable {
48 # Pin the nixpkgs flake in the installer to our cleaned up nixpkgs source.
49 # FIXME: this might be surprising and is really only needed for offline installations,
50 # see discussion in https://github.com/NixOS/nixpkgs/pull/204178#issuecomment-1336289021
51 nix.registry.nixpkgs.to = {
52 type = "path";
53 path = "${channelSources}/nixos";
54 };
55
56 # Provide the NixOS/Nixpkgs sources in /etc/nixos. This is required
57 # for nixos-install.
58 boot.postBootCommands = lib.mkAfter ''
59 if ! [ -e /var/lib/nixos/did-channel-init ]; then
60 echo "unpacking the NixOS/Nixpkgs sources..."
61 mkdir -p /nix/var/nix/profiles/per-user/root
62 ${config.nix.package.out}/bin/nix-env -p /nix/var/nix/profiles/per-user/root/channels \
63 -i ${channelSources} --quiet --option build-use-substitutes false \
64 ${lib.optionalString config.boot.initrd.systemd.enable "--option sandbox false"} # There's an issue with pivot_root
65 mkdir -m 0700 -p /root/.nix-defexpr
66 ln -s /nix/var/nix/profiles/per-user/root/channels /root/.nix-defexpr/channels
67 mkdir -m 0755 -p /var/lib/nixos
68 touch /var/lib/nixos/did-channel-init
69 fi
70 '';
71 };
72}