Unverified Commit 5653209e authored by Janne Heß's avatar Janne Heß
Browse files

nixos/systemd-initrd: Redo object specifications 

As requested by @roberth, we now have an option similar to
environment.etc. There's also extra store paths to copy and a way to
suppress store paths to make customizations possible.

We also link mount and umount to /bin to make recovery easier when
something fails
parent c465c8d7

nixos/modules/system/boot/systemd/initrd.nix

+86 −48
Original line number Diff line number Diff line
@@ -127,10 +127,16 @@ let 
    name = "initrd-emergency-env";

    paths = map getBin cfg.initrdBin;

    pathsToLink = ["/bin" "/sbin"];

    # Make recovery easier

    postBuild = ''

      ln -s ${cfg.package.util-linux}/bin/mount $out/bin/

      ln -s ${cfg.package.util-linux}/bin/umount $out/bin/

    '';

  };



  initialRamdisk = pkgs.makeInitrdNG {

    contents = cfg.objects;

    contents = map (path: { object = path; symlink = ""; }) (subtractLists cfg.suppressedStorePaths cfg.storePaths)

      ++ mapAttrsToList (_: v: { object = v.source; symlink = v.target; }) (filterAttrs (_: v: v.enable) cfg.contents);

  };



in {
@@ -142,31 +148,69 @@ in { 
      not yet supported by the intrd generated with this option.

    '';



    package = (lib.mkPackageOption pkgs "systemd" {

    package = (mkPackageOption pkgs "systemd" {

      default = "systemdMinimal";

    }) // {

      visible = false;

    };



    objects = mkOption {

      description = "List of objects to include in the initrd, and their symlinks";

    contents = mkOption {

      description = "Set of files that have to be linked into the initrd";

      example = literalExpression ''

        [ { object = "''${systemd}/lib/systemd/systemd"; symlink = "/init"; } ]

        {

          "/etc/hostname".text = "mymachine";

        }

      '';

      visible = false;

      type = types.listOf (types.submodule {

      default = {};

      type = types.attrsOf (types.submodule ({ config, options, name, ... }: {

        options = {

          object = mkOption {

          enable = mkEnableOption "copying of this file to initrd and symlinking it" // { default = true; };



          target = mkOption {

            type = types.path;

            description = "The object to include in initrd.";

            description = ''

              Path of the symlink.

            '';

            default = name;

          };

          symlink = mkOption {

            type = types.nullOr types.path;

            description = "A symlink to create in initrd pointing to the object.";



          text = mkOption {

            default = null;

            type = types.nullOr types.lines;

            description = "Text of the file.";

          };



          source = mkOption {

            type = types.path;

            description = "Path of the source file.";

          };

        };

      });



        config = {

          source = mkIf (config.text != null) (

            let name' = "initrd-" + baseNameOf name;

            in mkDerivedConfig options.text (pkgs.writeText name')

          );

        };

      }));

    };



    storePaths = mkOption {

      description = ''

        Store paths to copy into the initrd as well.

      '';

      type = types.listOf types.singleLineStr;

      default = [];

    };



    suppressedStorePaths = mkOption {

      description = ''

        Store paths specified in the storePaths option that

        should not be copied.

      '';

      type = types.listOf types.singleLineStr;

      default = [];

    };



    emergencyAccess = mkOption {
@@ -300,48 +344,42 @@ in { 
    boot.initrd.systemd = {

      initrdBin = [pkgs.bash pkgs.coreutils pkgs.kmod cfg.package] ++ config.system.fsPackages;



      objects = [

        { object = "${cfg.package}/lib/systemd/systemd"; symlink = "/init"; }

        { object = stage1Units; symlink = "/etc/systemd/system"; }



        # TODO: Limit this to the bare necessities

        { object = "${cfg.package}/lib"; }



        { object = "${cfg.package.util-linux}/bin/mount"; }

        { object = "${cfg.package.util-linux}/bin/umount"; }

        { object = "${cfg.package.util-linux}/bin/sulogin"; }

      contents = {

        "/init".source = "${cfg.package}/lib/systemd/systemd";

        "/etc/systemd/system".source = stage1Units;



        {

          object = builtins.toFile "system.conf" ''

        "/etc/systemd/system.conf".text = ''

          [Manager]

          DefaultEnvironment=PATH=/bin:/sbin

        '';

          symlink = "/etc/systemd/system.conf";

        }



        { object = config.environment.etc.os-release.source; symlink = "/etc/initrd-release"; }

        { object = config.environment.etc.os-release.source; symlink = "/etc/os-release"; }

        { object = fstab; symlink = "/etc/fstab"; }

        {

          object = "${modulesClosure}/lib/modules";

          symlink = "/lib/modules";

        }

        {

          symlink = "/etc/modules-load.d/nixos.conf";

          object = pkgs.writeText "nixos.conf"

            (lib.concatStringsSep "\n" config.boot.initrd.kernelModules);

        }

        "/etc/initrd-release".source = config.environment.etc.os-release.source;

        "/etc/os-release".source = config.environment.etc.os-release.source;

        "/etc/fstab".source = fstab;



        "/lib/modules".source = "${modulesClosure}/lib/modules";



        "/etc/modules-load.d/nixos.conf".text = concatStringsSep "\n" config.boot.initrd.kernelModules;



        "/etc/passwd".source = "${pkgs.fakeNss}/etc/passwd";

        "/etc/shadow".text = "root:${if isBool cfg.emergencyAccess then "!" else cfg.emergencyAccess}:::::::";



        "/bin".source = "${initrdBinEnv}/bin";

        "/sbin".source = "${initrdBinEnv}/sbin";



        "/etc/sysctl.d/nixos.conf".text = "kernel.modprobe = /sbin/modprobe";

      };



      storePaths = [

        # TODO: Limit this to the bare necessities

        "${cfg.package}/lib"



        "${cfg.package.util-linux}/bin/mount"

        "${cfg.package.util-linux}/bin/umount"

        "${cfg.package.util-linux}/bin/sulogin"



        { object = "${pkgs.fakeNss}/etc/passwd"; symlink = "/etc/passwd"; }

        # so NSS can look up usernames

        { object = "${pkgs.glibc}/lib/libnss_files.so"; }

        {

          object = builtins.toFile "shadow" "root:${if isBool cfg.emergencyAccess then "!" else cfg.emergencyAccess}:::::::";

          symlink = "/etc/shadow";

        }

        { object = "${initrdBinEnv}/bin"; symlink = "/bin"; }

        { object = "${initrdBinEnv}/sbin"; symlink = "/sbin"; }

        { object = builtins.toFile "sysctl.conf" "kernel.modprobe = /sbin/modprobe"; symlink = "/etc/sysctl.d/nixos.conf"; }

        "${pkgs.glibc}/lib/libnss_files.so"

      ];



      targets.initrd.aliases = ["default.target"];