audio services: use mkEnableOption

[langston-barrett]

Motivation for this change

Many, many services use the following snippet:

      enable = mkOption {
        default = false;
        type = types.bool;
        description = ''
          Whether to enable Mopidy, a music player daemon.
        '';
      };

That's why mkEnableOption was created!

  mkEnableOption = name: mkOption {
    default = false;
    example = true;
    description = "Whether to enable ${name}.";
    type = lib.types.bool;
  };

KISS, DRY, etc. I wrote the following (unreadable) script:

#!/usr/bin/env nix-shell
#! nix-shell -i bash -p ag

cd "$1"

for file in $(IFS=\n ag -l "enable = mkOption"); do
  perl -0777 -p -i -e 's/(.+?)enable\s+=\s+mkOption\s+\{.+?to enable (.+?)\..+?};/\1enable = mkEnableOption "\2";/igs' "$file"
done

which I propose we use on everything in nixos/modules. I wanted to create this small PR first to discuss the possible implications of that massive change before actually implementing it.

We'd definitely need to be cautious about only using this function on services that are disabled by default.

What do y'all think?

Things done

• Tested using sandboxing
  (nix.useSandbox on NixOS,
  or option build-use-sandbox in nix.conf
  on non-NixOS)
• Built on platform(s)
  • NixOS
  • OS X
  • Linux
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

[mention-bot]

@siddharthist, thanks for your PR! By analyzing the annotation information on this pull request, we identified @rickynils, @dmalikov and @shlevy to be potential reviewers

[fpletz]

We should definitely skim the diff, but that script should be very useful, thanks! 👍

Merging this as it won't be controversial. 😉