nixpkgs/nixos/modules/services/misc/nixos-manual.nix
aszlig c5bb43188d
nixos: Fix eval error for documentation.nixos
Introduced by 0f3b89bbed.

If services.nixosManual.showManual is enabled and
documentation.nixos.enable is not, there is no
config.system.build.manual available, so evaluation fails. For example
this is the case for the installer tests.

There is however an assertion which should catch exactly this, but it
isn't thrown because the usage of config.system.build.manual is
evaluated earlier than the assertions.

So I split the assertion off into a separate mkIf to make sure it is
shown appropriately and also fixed the installation-device profile to
enable documentation.nixos.

Signed-off-by: aszlig <aszlig@nix.build>
Cc: @oxij
2018-09-25 23:39:44 +02:00

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 = "${pkgs.w3m-nographics}/bin/w3m";
description = ''
Browser used to show the manual.
'';
};
};
config = mkMerge [
(mkIf cfg.showManual {
assertions = singleton {
assertion = cfgd.enable && cfgd.nixos.enable;
message = "Can't enable `services.nixosManual.showManual` without `documentation.nixos.enable`";
};
})
(mkIf (cfg.showManual && cfgd.enable && cfgd.nixos.enable) {
boot.extraTTYs = [ "tty${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";
};
};
})
];
}