nixpkgs/nixos/modules/misc/documentation.nix
Klemens Nanni 03d6c406fc
nixos/documentation: nixos-help: use w3m(1) by default
It is referenced in various places, but does not work out of the box:

	$ nixos-help
	/run/current-system/sw/bin/nixos-help: unable to start a web browser; please set $BROWSER

In the user-hidden fallbacks to xdg-open(1) and w3m(1), `nixos-help`
expects tools to be deliberately installed by users.

For default installations and new users in general, this is unlikely to
be the case.  Conversely, chances to use `nixos-help` are even higher
in such cases.

Use w3m-nographics by default to ensure documentation is always
available.  The documentation browser on ttyS8 already does so, but is
not accessible in every installation, e.g. VMs with only ttyS0 and SSH
available.

This obsoletes including it in the base profile's systemPackages,
so remove the @TODO as done.
2019-06-09 17:11:20 +02:00

208 lines
7.0 KiB
Nix

{ config, lib, pkgs, baseModules, extraModules, modules, ... }:
with lib;
let
cfg = config.documentation;
manualModules = baseModules ++ optionals cfg.nixos.includeAllModules (extraModules ++ modules);
/* For the purpose of generating docs, evaluate options with each derivation
in `pkgs` (recursively) replaced by a fake with path "\${pkgs.attribute.path}".
It isn't perfect, but it seems to cover a vast majority of use cases.
Caveat: even if the package is reached by a different means,
the path above will be shown and not e.g. `${config.services.foo.package}`. */
manual = import ../../doc/manual rec {
inherit pkgs config;
version = config.system.nixos.release;
revision = "release-${version}";
options =
let
scrubbedEval = evalModules {
modules = [ { nixpkgs.localSystem = config.nixpkgs.localSystem; } ] ++ manualModules;
args = (config._module.args) // { modules = [ ]; };
specialArgs = { pkgs = scrubDerivations "pkgs" pkgs; };
};
scrubDerivations = namePrefix: pkgSet: mapAttrs
(name: value:
let wholeName = "${namePrefix}.${name}"; in
if isAttrs value then
scrubDerivations wholeName value
// (optionalAttrs (isDerivation value) { outPath = "\${${wholeName}}"; })
else value
)
pkgSet;
in scrubbedEval.options;
};
helpScript = pkgs.writeScriptBin "nixos-help"
''
#! ${pkgs.runtimeShell} -e
# Finds first executable browser in a colon-separated list.
# (see how xdg-open defines BROWSER)
browser="$(
IFS=: ; for b in $BROWSER; do
[ -n "$(type -P "$b" || true)" ] && echo "$b" && break
done
)"
if [ -z "$browser" ]; then
browser="$(type -P xdg-open || true)"
if [ -z "$browser" ]; then
browser="${pkgs.w3m-nographics}/bin/w3m"
fi
fi
exec "$browser" ${manual.manualHTMLIndex}
'';
desktopItem = pkgs.makeDesktopItem {
name = "nixos-manual";
desktopName = "NixOS Manual";
genericName = "View NixOS documentation in a web browser";
icon = "nix-snowflake";
exec = "${helpScript}/bin/nixos-help";
categories = "System";
};
in
{
options = {
documentation = {
enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to install documentation of packages from
<option>environment.systemPackages</option> into the generated system path.
See "Multiple-output packages" chapter in the nixpkgs manual for more info.
'';
# which is at ../../../doc/multiple-output.xml
};
man.enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to install manual pages and the <command>man</command> command.
This also includes "man" outputs.
'';
};
info.enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to install info pages and the <command>info</command> command.
This also includes "info" outputs.
'';
};
doc.enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to install documentation distributed in packages' <literal>/share/doc</literal>.
Usually plain text and/or HTML.
This also includes "doc" outputs.
'';
};
dev.enable = mkOption {
type = types.bool;
default = false;
description = ''
Whether to install documentation targeted at developers.
<itemizedlist>
<listitem><para>This includes man pages targeted at developers if <option>man.enable</option> is
set (this also includes "devman" outputs).</para></listitem>
<listitem><para>This includes info pages targeted at developers if <option>info.enable</option>
is set (this also includes "devinfo" outputs).</para></listitem>
<listitem><para>This includes other pages targeted at developers if <option>doc.enable</option>
is set (this also includes "devdoc" outputs).</para></listitem>
</itemizedlist>
'';
};
nixos.enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to install NixOS's own documentation.
<itemizedlist>
<listitem><para>This includes man pages like
<citerefentry><refentrytitle>configuration.nix</refentrytitle>
<manvolnum>5</manvolnum></citerefentry> if <option>man.enable</option> is
set.</para></listitem>
<listitem><para>This includes the HTML manual and the <command>nixos-help</command> command if
<option>doc.enable</option> is set.</para></listitem>
</itemizedlist>
'';
};
nixos.includeAllModules = mkOption {
type = types.bool;
default = false;
description = ''
Whether the generated NixOS's documentation should include documentation for all
the options from all the NixOS modules included in the current
<literal>configuration.nix</literal>. Disabling this will make the manual
generator to ignore options defined outside of <literal>baseModules</literal>.
'';
};
};
};
config = mkIf cfg.enable (mkMerge [
(mkIf cfg.man.enable {
environment.systemPackages = [ pkgs.man-db ];
environment.pathsToLink = [ "/share/man" ];
environment.extraOutputsToInstall = [ "man" ] ++ optional cfg.dev.enable "devman";
environment.etc."man.conf".source = "${pkgs.man-db}/etc/man_db.conf";
})
(mkIf cfg.info.enable {
environment.systemPackages = [ pkgs.texinfoInteractive ];
environment.pathsToLink = [ "/share/info" ];
environment.extraOutputsToInstall = [ "info" ] ++ optional cfg.dev.enable "devinfo";
environment.extraSetup = ''
if [ -w $out/share/info ]; then
shopt -s nullglob
for i in $out/share/info/*.info $out/share/info/*.info.gz; do
${pkgs.buildPackages.texinfo}/bin/install-info $i $out/share/info/dir
done
fi
'';
})
(mkIf cfg.doc.enable {
environment.pathsToLink = [ "/share/doc" ];
environment.extraOutputsToInstall = [ "doc" ] ++ optional cfg.dev.enable "devdoc";
})
(mkIf cfg.nixos.enable {
system.build.manual = manual;
environment.systemPackages = []
++ optional cfg.man.enable manual.manpages
++ optionals cfg.doc.enable ([ manual.manualHTML helpScript ]
++ optionals config.services.xserver.enable [ desktopItem pkgs.nixos-icons ]);
services.mingetty.helpLine = mkIf cfg.doc.enable (
"\nRun `nixos-help` "
+ optionalString config.services.nixosManual.showManual "or press <Alt-F${toString config.services.nixosManual.ttyNumber}> "
+ "for the NixOS manual."
);
})
]);
}