depot/pkgs/servers/web-apps/discourse/default.nix

{
  stdenv,
  pkgs,
  makeWrapper,
  runCommand,
  lib,
  writeShellScript,
  fetchFromGitHub,
  bundlerEnv,
  callPackage,

  ruby_3_2,
  replace,
  gzip,
  gnutar,
  git,
  cacert,
  util-linux,
  gawk,
  nettools,
  imagemagick,
  optipng,
  pngquant,
  libjpeg,
  jpegoptim,
  gifsicle,
  jhead,
  oxipng,
  libpsl,
  redis,
  postgresql,
  which,
  brotli,
  procps,
  rsync,
  icu,
  fetchYarnDeps,
  yarn,
  fixup-yarn-lock,
  nodePackages,
  nodejs_18,
  jq,
  moreutils,
  terser,
  uglify-js,

  plugins ? [ ],
}@args:

let
  version = "3.3.2";

  src = fetchFromGitHub {
    owner = "discourse";
    repo = "discourse";
    rev = "v${version}";
    sha256 = "sha256-FaPcUta5z/8oasw+9zGBRZnUVYD8eCo1t/XwwsFoSM8=";
  };

  ruby = ruby_3_2;

  runtimeDeps = [
    # For backups, themes and assets
    rubyEnv.wrappedRuby
    rsync
    gzip
    gnutar
    git
    brotli
    nodejs_18

    # Misc required system utils
    which
    procps # For ps and kill
    util-linux # For renice
    gawk
    nettools # For hostname

    # Image optimization
    imagemagick
    optipng
    oxipng
    pngquant
    libjpeg
    jpegoptim
    gifsicle
    nodePackages.svgo
    jhead
  ];

  runtimeEnv = {
    HOME = "/run/discourse/home";
    RAILS_ENV = "production";
    UNICORN_LISTENER = "/run/discourse/sockets/unicorn.sock";
  };

  mkDiscoursePlugin =
    {
      name ? null,
      pname ? null,
      version ? null,
      meta ? null,
      bundlerEnvArgs ? { },
      preserveGemsDir ? false,
      src,
      ...
    }@args:
    let
      rubyEnv = bundlerEnv (
        bundlerEnvArgs
        // {
          inherit
            name
            pname
            version
            ruby
            ;
        }
      );
    in
    stdenv.mkDerivation (
      builtins.removeAttrs args [ "bundlerEnvArgs" ]
      // {
        pluginName = if name != null then name else "${pname}-${version}";
        dontConfigure = true;
        dontBuild = true;
        installPhase =
          ''
            runHook preInstall
            mkdir -p $out
            cp -r * $out/
          ''
          + lib.optionalString (bundlerEnvArgs != { }) (
            if preserveGemsDir then
              ''
                cp -r ${rubyEnv}/lib/ruby/gems/* $out/gems/
              ''
            else
              ''
                if [[ -e $out/gems ]]; then
                  echo "Warning: The repo contains a 'gems' directory which will be removed!"
                  echo "         If you need to preserve it, set 'preserveGemsDir = true'."
                  rm -r $out/gems
                fi
                ln -sf ${rubyEnv}/lib/ruby/gems $out/gems
              ''
              + ''
                runHook postInstall
              ''
          );
      }
    );

  rake =
    runCommand "discourse-rake"
      {
        nativeBuildInputs = [ makeWrapper ];
      }
      ''
        mkdir -p $out/bin
        makeWrapper ${rubyEnv}/bin/rake $out/bin/discourse-rake \
            ${
              lib.concatStrings (lib.mapAttrsToList (name: value: "--set ${name} '${value}' ") runtimeEnv)
            } \
            --prefix PATH : ${lib.makeBinPath runtimeDeps} \
            --set RAKEOPT '-f ${discourse}/share/discourse/Rakefile' \
            --chdir '${discourse}/share/discourse'
      '';

  rubyEnv = bundlerEnv {
    name = "discourse-ruby-env-${version}";
    inherit version ruby;
    gemdir = ./rubyEnv;
    gemset =
      let
        gems = import ./rubyEnv/gemset.nix;
      in
      gems
      // {
        mini_racer = gems.mini_racer // {
          buildInputs = [ icu ];
          dontBuild = false;
          NIX_LDFLAGS = "-licui18n";
        };
        libv8-node =
          let
            noopScript = writeShellScript "noop" "exit 0";
            linkFiles = writeShellScript "link-files" ''
              cd ../..

              mkdir -p vendor/v8/${stdenv.hostPlatform.system}/libv8/obj/
              ln -s "${nodejs_18.libv8}/lib/libv8.a" vendor/v8/${stdenv.hostPlatform.system}/libv8/obj/libv8_monolith.a

              ln -s ${nodejs_18.libv8}/include vendor/v8/include

              mkdir -p ext/libv8-node
              echo '--- !ruby/object:Libv8::Node::Location::Vendor {}' >ext/libv8-node/.location.yml
            '';
          in
          gems.libv8-node
          // {
            dontBuild = false;
            postPatch = ''
              cp ${noopScript} libexec/build-libv8
              cp ${noopScript} libexec/build-monolith
              cp ${noopScript} libexec/download-node
              cp ${noopScript} libexec/extract-node
              cp ${linkFiles} libexec/inject-libv8
            '';
          };
        mini_suffix = gems.mini_suffix // {
          propagatedBuildInputs = [ libpsl ];
          dontBuild = false;
          # Use our libpsl instead of the vendored one, which isn't
          # available for aarch64. It has to be called
          # libpsl.x86_64.so or it isn't found.
          postPatch = ''
            cp $(readlink -f ${lib.getLib libpsl}/lib/libpsl.so) vendor/libpsl.x86_64.so
          '';
        };
      };

    groups = [
      "default"
      "assets"
      "development"
      "test"
    ];
  };

  assets = stdenv.mkDerivation {
    pname = "discourse-assets";
    inherit version src;

    yarnOfflineCache = fetchYarnDeps {
      yarnLock = src + "/yarn.lock";
      hash = "sha256-cSQofaULCmPuWGxS+hK4KlRq9lSkCPiYvhax9X6Dor8=";
    };

    nativeBuildInputs = runtimeDeps ++ [
      postgresql
      redis
      uglify-js
      terser
      yarn
      jq
      moreutils
      fixup-yarn-lock
    ];

    outputs = [
      "out"
      "javascripts"
      "node_modules"
    ];

    patches = [
      # Use the Ruby API version in the plugin gem path, to match the
      # one constructed by bundlerEnv
      ./plugin_gem_api_version.patch

      # Change the path to the auto generated plugin assets, which
      # defaults to the plugin's directory and isn't writable at the
      # time of asset generation
      ./auto_generated_path.patch

      # Fix the rake command used to recursively execute itself in the
      # assets precompilation task.
      ./assets_rake_command.patch

      # Little does he know, so he decided there is no need to generate the
      # theme-transpiler over and over again. Which at the same time allows the removal
      # of javascript devDependencies from the runtime environment.
      ./prebuild-theme-transpiler.patch
    ];

    env.RAILS_ENV = "production";

    # We have to set up an environment that is close enough to
    # production ready or the assets:precompile task refuses to
    # run. This means that Redis and PostgreSQL has to be running and
    # database migrations performed.
    preBuild = ''
      # Yarn wants a real home directory to write cache, config, etc to
      export HOME=$NIX_BUILD_TOP/fake_home

      yarn_install() {
        local offlineCache=$1 yarnLock=$2

        # Make yarn install packages from our offline cache, not the registry
        yarn config --offline set yarn-offline-mirror $offlineCache

        # Fixup "resolved"-entries in yarn.lock to match our offline cache
        fixup-yarn-lock $yarnLock

        # Install while ignoring hook scripts
        yarn --offline --ignore-scripts --cwd $(dirname $yarnLock) install
      }

      # Install runtime and devDependencies.
      # The dev deps are necessary for generating the theme-transpiler executed as dependent task
      # assets:precompile:theme_transpiler before db:migrate and unfortunately also in the runtime
      yarn_install $yarnOfflineCache yarn.lock

      # Patch before running postinstall hook script
      patchShebangs node_modules/
      patchShebangs --build app/assets/javascripts
      yarn --offline --cwd app/assets/javascripts run postinstall
      export SSL_CERT_FILE=${cacert}/etc/ssl/certs/ca-bundle.crt

      redis-server >/dev/null &

      initdb -A trust $NIX_BUILD_TOP/postgres >/dev/null
      postgres -D $NIX_BUILD_TOP/postgres -k $NIX_BUILD_TOP >/dev/null &
      export PGHOST=$NIX_BUILD_TOP

      echo "Waiting for Redis and PostgreSQL to be ready.."
      while ! redis-cli --scan >/dev/null || ! psql -l >/dev/null; do
        sleep 0.1
      done

      psql -d postgres -tAc 'CREATE USER "discourse"'
      psql -d postgres -tAc 'CREATE DATABASE "discourse" OWNER "discourse"'
      psql 'discourse' -tAc "CREATE EXTENSION IF NOT EXISTS pg_trgm"
      psql 'discourse' -tAc "CREATE EXTENSION IF NOT EXISTS hstore"

      ${lib.concatMapStringsSep "\n" (p: "ln -sf ${p} plugins/${p.pluginName or ""}") plugins}

      bundle exec rake db:migrate >/dev/null
      chmod -R +w tmp
    '';

    buildPhase = ''
      runHook preBuild

      bundle exec rake assets:precompile

      runHook postBuild
    '';

    installPhase = ''
      runHook preInstall

      mv public/assets $out

      mv node_modules $node_modules

      rm -r app/assets/javascripts/plugins
      mv app/assets/javascripts $javascripts
      ln -sf /run/discourse/assets/javascripts/plugins $javascripts/plugins

      runHook postInstall
    '';
  };

  discourse = stdenv.mkDerivation {
    pname = "discourse";
    inherit version src;

    buildInputs = [
      rubyEnv
      rubyEnv.wrappedRuby
      rubyEnv.bundler
    ];

    patches = [
      # Load a separate NixOS site settings file
      ./nixos_defaults.patch

      # Add a noninteractive admin creation task
      ./admin_create.patch

      # Add the path to the CA cert bundle to make TLS work
      ./action_mailer_ca_cert.patch

      # Log Unicorn messages to the journal and make request timeout
      # configurable
      ./unicorn_logging_and_timeout.patch

      # Use the Ruby API version in the plugin gem path, to match the
      # one constructed by bundlerEnv
      ./plugin_gem_api_version.patch

      # Change the path to the auto generated plugin assets, which
      # defaults to the plugin's directory and isn't writable at the
      # time of asset generation
      ./auto_generated_path.patch

      # Make sure the notification email setting applies
      ./notification_email.patch

      # Little does he know, so he decided there is no need to generate the
      # theme-transpiler over and over again. Which at the same time allows the removal
      # of javascript devDependencies from the runtime environment.
      ./prebuild-theme-transpiler.patch
    ];

    postPatch = ''
      # Always require lib-files and application.rb through their store
      # path, not their relative state directory path. This gets rid of
      # warnings and means we don't have to link back to lib from the
      # state directory.
      find config -type f -name "*.rb" -execdir \
        sed -Ei "s,(\.\./)+(lib|app)/,$out/share/discourse/\2/," {} \;
      find config -maxdepth 1 -type f -name "*.rb" -execdir \
        sed -Ei "s,require_relative (\"|')([[:alnum:]].*)(\"|'),require_relative '$out/share/discourse/config/\2'," {} \;
    '';

    buildPhase = ''
      runHook preBuild

      mv config config.dist
      mv public public.dist

      runHook postBuild
    '';

    installPhase = ''
      runHook preInstall

      mkdir -p $out/share
      cp -r . $out/share/discourse
      rm -r $out/share/discourse/log
      ln -sf /var/log/discourse $out/share/discourse/log
      ln -sf /var/lib/discourse/tmp $out/share/discourse/tmp
      ln -sf /run/discourse/config $out/share/discourse/config
      ln -sf /run/discourse/public $out/share/discourse/public
      # This needs to be copied because of symlinks in node_modules
      # Also this needs to be full node_modules (including dev deps) because without loader.js it just throws 500
      cp -r ${assets.node_modules} $out/share/discourse/node_modules
      ln -sf ${assets} $out/share/discourse/public.dist/assets
      rm -r $out/share/discourse/app/assets/javascripts
      ln -sf ${assets.javascripts} $out/share/discourse/app/assets/javascripts
      ${lib.concatMapStringsSep "\n" (
        p: "ln -sf ${p} $out/share/discourse/plugins/${p.pluginName or ""}"
      ) plugins}

      runHook postInstall
    '';

    meta = with lib; {
      homepage = "https://www.discourse.org/";
      platforms = platforms.linux;
      maintainers = with maintainers; [ talyz ];
      license = licenses.gpl2Plus;
      description = "Discourse is an open source discussion platform";
    };

    passthru = {
      inherit
        rubyEnv
        runtimeEnv
        runtimeDeps
        rake
        mkDiscoursePlugin
        assets
        ;
      inherit (pkgs)
        discourseAllPlugins
        ;
      enabledPlugins = plugins;
      plugins = callPackage ./plugins/all-plugins.nix { inherit mkDiscoursePlugin; };
      ruby = rubyEnv.wrappedRuby;
      tests = import ../../../../nixos/tests/discourse.nix {
        inherit (stdenv) system;
        inherit pkgs;
        package = pkgs.discourse.override args;
      };
    };
  };
in
discourse