nixpkgs/nixos/modules/services/misc/nixos-manual.nix
2020-01-02 16:53:15 -08:00

73 lines
1.8 KiB
Nix

# This module optionally starts a browser that shows the NixOS manual
# on one of the virtual consoles which is useful for the installation
# CD.
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.services.nixosManual;
cfgd = config.documentation;
in
{
options = {
# TODO(@oxij): rename this to `.enable` eventually.
services.nixosManual.showManual = mkOption {
type = types.bool;
default = false;
description = ''
Whether to show the NixOS manual on one of the virtual
consoles.
'';
};
services.nixosManual.ttyNumber = mkOption {
type = types.int;
default = 8;
description = ''
Virtual console on which to show the manual.
'';
};
services.nixosManual.browser = mkOption {
type = types.path;
default = "${pkgs.w3m-nographics}/bin/w3m";
description = ''
Browser used to show the manual.
'';
};
};
config = mkMerge [
(mkIf cfg.showManual {
assertions = singleton {
assertion = cfgd.enable && cfgd.nixos.enable;
message = "Can't enable `services.nixosManual.showManual` without `documentation.nixos.enable`";
};
})
(mkIf (cfg.showManual && cfgd.enable && cfgd.nixos.enable) {
console.extraTTYs = [ "tty${toString cfg.ttyNumber}" ];
systemd.services.nixos-manual = {
description = "NixOS Manual";
wantedBy = [ "multi-user.target" ];
serviceConfig = {
ExecStart = "${cfg.browser} ${config.system.build.manual.manualHTMLIndex}";
StandardInput = "tty";
StandardOutput = "tty";
TTYPath = "/dev/tty${toString cfg.ttyNumber}";
TTYReset = true;
TTYVTDisallocate = true;
Restart = "always";
};
};
})
];
}