Craft Happy Lager Demo with Nix

happy-lager.nix

{ callPackage
, fetchFromGitHub
, runCommand
, writeableDirStr      ? "/var/lib/writeable" # e.g. "/var/lib/phpfpm/HappyLager"
, writeableOrigDirName ? "_writeable"         # e.g. "_writeable"
, ...
}:
let
  craft-cms-deriv = { fetchzip, runCommand, ... }:
    let
      version = "2.6";
      build   = "2954";
    in fetchzip {
      url       = "https://download.buildwithcraft.com/craft/${version}/${version}.${build}/Craft-${version}.${build}.zip";
      stripRoot = false;
      sha256    = "0xl6qfavnx5j5b4nrqsbs2r9lv3m20x66m73j8y75risr0251wrl";
    };

  craft-cms = callPackage craft-cms-deriv {};

  appName = "craft-cms-demo-happy-lager";

  src = fetchFromGitHub {
    owner  = "pixelandtonic";
    repo   = "HappyLager";
    rev    = "35f1ac5720d74f9f5c2bd2ce2180fae94cb97d92";
    sha256 = "1ma51j0i9pc6h4c65ndz8b9256m1fqqsa8hhq4ss39ybdk8qlxvb";
  };

in runCommand appName { inherit src; } ''
  mkdir -p "$out"
  cp -r "$src"/* "$out"
  ls "$out"
  cp -r "${craft-cms}/craft/app" "$out/craft"   # This fails with cp: cannot create directory '/nix/store/j42z3dbqq6f61nj6n4a62vfxh75r8wh4-HappyLager-CraftCMS-Demo/craft/app': Permission denied
  find $out -name ".htaccess" | xargs rm

  writeable_orig_dir="$out/${writeableOrigDirName}"
  mkdir -p "$writeable_orig_dir"
  mv "$out/config"  "$writeable_orig_dir"
  mv "$out/storage" "$writeable_orig_dir"
  ln -s "${writeableDirStr}/config"  "$out/config"
  ln -s "${writeableDirStr}/storage" "$out/storage"
''