nixos/lemmy: init

Co-authored-by: Raphael Megzari <raphael@megzari.com>

nixos/modules/module-list.nix

@@ -985,6 +985,7 @@
   ./services/web-apps/jirafeau.nix
   ./services/web-apps/jitsi-meet.nix
   ./services/web-apps/keycloak.nix
+  ./services/web-apps/lemmy.nix
   ./services/web-apps/limesurvey.nix
   ./services/web-apps/mastodon.nix
   ./services/web-apps/mattermost.nix

nixos/modules/services/web-apps/lemmy.md

@@ -0,0 +1,34 @@
+# Lemmy {#module-services-lemmy}
+
+Lemmy is a federated alternative to reddit in rust.
+
+## Quickstart {#module-services-lemmy-quickstart}
+
+the minimum to start lemmy is
+
+```nix
+services.lemmy = {
+  enable = true;
+  settings = {
+    hostname = "lemmy.union.rocks";
+    database.createLocally = true;
+  };
+  jwtSecretPath = "/run/secrets/lemmyJwt";
+  caddy.enable = true;
+}
+```
+
+(note that you can use something like agenix to get your secret jwt to the specified path)
+
+this will start the backend on port 8536 and the frontend on port 1234.
+It will expose your instance with a caddy reverse proxy to the hostname you've provided.
+Postgres will be initialized on that same instance automatically.
+
+## Usage {#module-services-lemmy-usage}
+
+On first connection you will be asked to define an admin user.
+
+## Missing {#module-services-lemmy-missing}
+
+- Exposing with nginx is not implemented yet.
+- This has been tested using a local database with a unix socket connection. Using different database settings will likely require modifications

nixos/modules/services/web-apps/lemmy.nix

@@ -0,0 +1,238 @@
+{ lib, pkgs, config, ... }:
+with lib;
+let
+  cfg = config.services.lemmy;
+  settingsFormat = pkgs.formats.json { };
+in
+{
+  meta.maintainers = with maintainers; [ happysalada ];
+  # Don't edit the docbook xml directly, edit the md and generate it:
+  # `pandoc lemmy.md -t docbook --top-level-division=chapter --extract-media=media -f markdown+smart > lemmy.xml`
+  meta.doc = ./lemmy.xml;
+
+  options.services.lemmy = {
+
+    enable = mkEnableOption "lemmy a federated alternative to reddit in rust";
+
+    jwtSecretPath = mkOption {
+      type = types.path;
+      description = "Path to read the jwt secret from.";
+    };
+
+    ui = {
+      port = mkOption {
+        type = types.port;
+        default = 1234;
+        description = "Port where lemmy-ui should listen for incoming requests.";
+      };
+    };
+
+    caddy.enable = mkEnableOption "exposing lemmy with the caddy reverse proxy";
+
+    settings = mkOption {
+      default = { };
+      description = "Lemmy configuration";
+
+      type = types.submodule {
+        freeformType = settingsFormat.type;
+
+        options.hostname = mkOption {
+          type = types.str;
+          default = null;
+          description = "The domain name of your instance (eg 'lemmy.ml').";
+        };
+
+        options.port = mkOption {
+          type = types.port;
+          default = 8536;
+          description = "Port where lemmy should listen for incoming requests.";
+        };
+
+        options.federation = {
+          enabled = mkEnableOption "activitypub federation";
+        };
+
+        options.captcha = {
+          enabled = mkOption {
+            type = types.bool;
+            default = true;
+            description = "Enable Captcha.";
+          };
+          difficulty = mkOption {
+            type = types.enum [ "easy" "medium" "hard" ];
+            default = "medium";
+            description = "The difficultly of the captcha to solve.";
+          };
+        };
+
+        options.database.createLocally = mkEnableOption "creation of database on the instance";
+
+      };
+    };
+
+  };
+
+  config =
+    let
+      localPostgres = (cfg.settings.database.host == "localhost" || cfg.settings.database.host == "/run/postgresql");
+    in
+    lib.mkIf cfg.enable {
+      services.lemmy.settings = (mapAttrs (name: mkDefault)
+        {
+          bind = "127.0.0.1";
+          tls_enabled = true;
+          pictrs_url = with config.services.pict-rs; "http://${address}:${toString port}";
+          actor_name_max_length = 20;
+
+          rate_limit.message = 180;
+          rate_limit.message_per_second = 60;
+          rate_limit.post = 6;
+          rate_limit.post_per_second = 600;
+          rate_limit.register = 3;
+          rate_limit.register_per_second = 3600;
+          rate_limit.image = 6;
+          rate_limit.image_per_second = 3600;
+        } // {
+        database = mapAttrs (name: mkDefault) {
+          user = "lemmy";
+          host = "/run/postgresql";
+          port = 5432;
+          database = "lemmy";
+          pool_size = 5;
+        };
+      });
+
+      services.postgresql = mkIf localPostgres {
+        enable = mkDefault true;
+      };
+
+      services.pict-rs.enable = true;
+
+      services.caddy = mkIf cfg.caddy.enable {
+        enable = mkDefault true;
+        virtualHosts."${cfg.settings.hostname}" = {
+          extraConfig = ''
+            handle_path /static/* {
+              root * ${pkgs.lemmy-ui}/dist
+              file_server
+            }
+            @for_backend {
+              path /api/* /pictrs/* feeds/* nodeinfo/*
+            }
+            handle @for_backend {
+              reverse_proxy 127.0.0.1:${toString cfg.settings.port}
+            }
+            @post {
+              method POST
+            }
+            handle @post {
+              reverse_proxy 127.0.0.1:${toString cfg.settings.port}
+            }
+            @jsonld {
+              header Accept "application/activity+json"
+              header Accept "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\""
+            }
+            handle @jsonld {
+              reverse_proxy 127.0.0.1:${toString cfg.settings.port}
+            }
+            handle {
+              reverse_proxy 127.0.0.1:${toString cfg.ui.port}
+            }
+          '';
+        };
+      };
+
+      assertions = [{
+        assertion = cfg.settings.database.createLocally -> localPostgres;
+        message = "if you want to create the database locally, you need to use a local database";
+      }];
+
+      systemd.services.lemmy = {
+        description = "Lemmy server";
+
+        environment = {
+          LEMMY_CONFIG_LOCATION = "/run/lemmy/config.hjson";
+
+          # Verify how this is used, and don't put the password in the nix store
+          LEMMY_DATABASE_URL = with cfg.settings.database;"postgres:///${database}?host=${host}";
+        };
+
+        documentation = [
+          "https://join-lemmy.org/docs/en/administration/from_scratch.html"
+          "https://join-lemmy.org/docs"
+        ];
+
+        wantedBy = [ "multi-user.target" ];
+
+        after = [ "pict-rs.service " ] ++ lib.optionals cfg.settings.database.createLocally [ "lemmy-postgresql.service" ];
+
+        requires = lib.optionals cfg.settings.database.createLocally [ "lemmy-postgresql.service" ];
+
+        # script is needed here since loadcredential is not accessible on ExecPreStart
+        script = ''
+          ${pkgs.coreutils}/bin/install -m 600 ${settingsFormat.generate "config.hjson" cfg.settings} /run/lemmy/config.hjson
+          jwtSecret="$(< $CREDENTIALS_DIRECTORY/jwt_secret )"
+          ${pkgs.jq}/bin/jq ".jwt_secret = \"$jwtSecret\"" /run/lemmy/config.hjson | ${pkgs.moreutils}/bin/sponge /run/lemmy/config.hjson
+          ${pkgs.lemmy-server}/bin/lemmy_server
+        '';
+
+        serviceConfig = {
+          DynamicUser = true;
+          RuntimeDirectory = "lemmy";
+          LoadCredential = "jwt_secret:${cfg.jwtSecretPath}";
+        };
+      };
+
+      systemd.services.lemmy-ui = {
+        description = "Lemmy ui";
+
+        environment = {
+          LEMMY_UI_HOST = "127.0.0.1:${toString cfg.ui.port}";
+          LEMMY_INTERNAL_HOST = "127.0.0.1:${toString cfg.settings.port}";
+          LEMMY_EXTERNAL_HOST = cfg.settings.hostname;
+          LEMMY_HTTPS = "false";
+        };
+
+        documentation = [
+          "https://join-lemmy.org/docs/en/administration/from_scratch.html"
+          "https://join-lemmy.org/docs"
+        ];
+
+        wantedBy = [ "multi-user.target" ];
+
+        after = [ "lemmy.service" ];
+
+        requires = [ "lemmy.service" ];
+
+        serviceConfig = {
+          DynamicUser = true;
+          WorkingDirectory = "${pkgs.lemmy-ui}";
+          ExecStart = "${pkgs.nodejs}/bin/node ${pkgs.lemmy-ui}/dist/js/server.js";
+        };
+      };
+
+      systemd.services.lemmy-postgresql = mkIf cfg.settings.database.createLocally {
+        description = "Lemmy postgresql db";
+        after = [ "postgresql.service" ];
+        bindsTo = [ "postgresql.service" ];
+        requiredBy = [ "lemmy.service" ];
+        partOf = [ "lemmy.service" ];
+        script = with cfg.settings.database; ''
+          PSQL() {
+            ${config.services.postgresql.package}/bin/psql --port=${toString cfg.settings.database.port} "$@"
+          }
+          # check if the database already exists
+          if ! PSQL -lqt | ${pkgs.coreutils}/bin/cut -d \| -f 1 | ${pkgs.gnugrep}/bin/grep -qw ${database} ; then
+            PSQL -tAc "CREATE ROLE ${user} WITH LOGIN;"
+            PSQL -tAc "CREATE DATABASE ${database} WITH OWNER ${user};"
+          fi
+        '';
+        serviceConfig = {
+          User = config.services.postgresql.superUser;
+          Type = "oneshot";
+          RemainAfterExit = true;
+        };
+      };
+    };
+
+}

nixos/modules/services/web-apps/lemmy.xml

@@ -0,0 +1,56 @@
+<chapter xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="module-services-lemmy">
+  <title>Lemmy</title>
+  <para>
+    Lemmy is a federated alternative to reddit in rust.
+  </para>
+  <section xml:id="module-services-lemmy-quickstart">
+    <title>Quickstart</title>
+    <para>
+      the minimum to start lemmy is
+    </para>
+    <programlisting language="bash">
+services.lemmy = {
+  enable = true;
+  settings = {
+    hostname = &quot;lemmy.union.rocks&quot;;
+    database.createLocally = true;
+  };
+  jwtSecretPath = &quot;/run/secrets/lemmyJwt&quot;;
+  caddy.enable = true;
+}
+</programlisting>
+    <para>
+      (note that you can use something like agenix to get your secret
+      jwt to the specified path)
+    </para>
+    <para>
+      this will start the backend on port 8536 and the frontend on port
+      1234. It will expose your instance with a caddy reverse proxy to
+      the hostname you’ve provided. Postgres will be initialized on that
+      same instance automatically.
+    </para>
+  </section>
+  <section xml:id="module-services-lemmy-usage">
+    <title>Usage</title>
+    <para>
+      On first connection you will be asked to define an admin user.
+    </para>
+  </section>
+  <section xml:id="module-services-lemmy-missing">
+    <title>Missing</title>
+    <itemizedlist spacing="compact">
+      <listitem>
+        <para>
+          Exposing with nginx is not implemented yet.
+        </para>
+      </listitem>
+      <listitem>
+        <para>
+          This has been tested using a local database with a unix socket
+          connection. Using different database settings will likely
+          require modifications
+        </para>
+      </listitem>
+    </itemizedlist>
+  </section>
+</chapter>

pkgs/servers/web-apps/lemmy/ui.nix

@@ -57,7 +57,8 @@ mkYarnPackage {
 
   preInstall = ''
     mkdir $out
-    cp -R ./deps/lemmy-ui/dist/assets $out
+    cp -R ./deps/lemmy-ui/dist $out
+    cp -R ./node_modules $out
   '';
 
   distPhase = "true";