nixpkgs-suyu/nixos/modules/hardware/printers.nix
Michele Guerini Rocco 5dff7733aa
Merge pull request #203454 from rnhmjoj/pr-cups-socket
nixos/hardware/printers: stop cupsd when unneeded
2022-12-21 23:06:00 +01:00

135 lines
5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.hardware.printers;
ppdOptionsString = options: optionalString (options != {})
(concatStringsSep " "
(mapAttrsToList (name: value: "-o '${name}'='${value}'") options)
);
ensurePrinter = p: ''
${pkgs.cups}/bin/lpadmin -p '${p.name}' -E \
${optionalString (p.location != null) "-L '${p.location}'"} \
${optionalString (p.description != null) "-D '${p.description}'"} \
-v '${p.deviceUri}' \
-m '${p.model}' \
${ppdOptionsString p.ppdOptions}
'';
ensureDefaultPrinter = name: ''
${pkgs.cups}/bin/lpadmin -d '${name}'
'';
# "graph but not # or /" can't be implemented as regex alone due to missing lookahead support
noInvalidChars = str: all (c: c != "#" && c != "/") (stringToCharacters str);
printerName = (types.addCheck (types.strMatching "[[:graph:]]+") noInvalidChars)
// { description = "printable string without spaces, # and /"; };
in {
options = {
hardware.printers = {
ensureDefaultPrinter = mkOption {
type = types.nullOr printerName;
default = null;
description = lib.mdDoc ''
Ensures the named printer is the default CUPS printer / printer queue.
'';
};
ensurePrinters = mkOption {
description = lib.mdDoc ''
Will regularly ensure that the given CUPS printers are configured as declared here.
If a printer's options are manually changed afterwards, they will be overwritten eventually.
This option will never delete any printer, even if removed from this list.
You can check existing printers with {command}`lpstat -s`
and remove printers with {command}`lpadmin -x <printer-name>`.
Printers not listed here can still be manually configured.
'';
default = [];
type = types.listOf (types.submodule {
options = {
name = mkOption {
type = printerName;
example = "BrotherHL_Workroom";
description = lib.mdDoc ''
Name of the printer / printer queue.
May contain any printable characters except "/", "#", and space.
'';
};
location = mkOption {
type = types.nullOr types.str;
default = null;
example = "Workroom";
description = lib.mdDoc ''
Optional human-readable location.
'';
};
description = mkOption {
type = types.nullOr types.str;
default = null;
example = "Brother HL-5140";
description = lib.mdDoc ''
Optional human-readable description.
'';
};
deviceUri = mkOption {
type = types.str;
example = literalExpression ''
"ipp://printserver.local/printers/BrotherHL_Workroom"
"usb://HP/DESKJET%20940C?serial=CN16E6C364BH"
'';
description = lib.mdDoc ''
How to reach the printer.
{command}`lpinfo -v` shows a list of supported device URIs and schemes.
'';
};
model = mkOption {
type = types.str;
example = literalExpression ''
"gutenprint.''${lib.versions.majorMinor (lib.getVersion pkgs.gutenprint)}://brother-hl-5140/expert"
'';
description = lib.mdDoc ''
Location of the ppd driver file for the printer.
{command}`lpinfo -m` shows a list of supported models.
'';
};
ppdOptions = mkOption {
type = types.attrsOf types.str;
example = {
PageSize = "A4";
Duplex = "DuplexNoTumble";
};
default = {};
description = lib.mdDoc ''
Sets PPD options for the printer.
{command}`lpoptions [-p printername] -l` shows supported PPD options for the given printer.
'';
};
};
});
};
};
};
config = mkIf (cfg.ensurePrinters != [] && config.services.printing.enable) {
systemd.services.ensure-printers = {
description = "Ensure NixOS-configured CUPS printers";
wantedBy = [ "multi-user.target" ];
wants = [ "cups.service" ];
after = [ "cups.service" ];
serviceConfig = {
Type = "oneshot";
RemainAfterExit = true;
};
script = concatStringsSep "\n" [
(concatMapStrings ensurePrinter cfg.ensurePrinters)
(optionalString (cfg.ensureDefaultPrinter != null)
(ensureDefaultPrinter cfg.ensureDefaultPrinter))
# Note: if cupsd is "stateless" the service can't be stopped,
# otherwise the configuration will be wiped on the next start.
(optionalString (with config.services.printing; startWhenNeeded && !stateless)
"systemctl stop cups.service")
];
};
};
}