From c1ffe096312ca96aca76b07fa0db465d44331778 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Tue, 5 Mar 2024 12:32:40 +0000
Subject: [PATCH] nixos: services: add forgejo

---
 modules/nixos/services/default.nix         |   1 +
 modules/nixos/services/forgejo/default.nix | 162 +++++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100644 modules/nixos/services/forgejo/default.nix

diff --git a/modules/nixos/services/default.nix b/modules/nixos/services/default.nix
index 90dd3e1..3b32d06 100644
--- a/modules/nixos/services/default.nix
+++ b/modules/nixos/services/default.nix
@@ -10,6 +10,7 @@
     ./drone
     ./fail2ban
     ./flood
+    ./forgejo
     ./gitea
     ./grocy
     ./indexers
diff --git a/modules/nixos/services/forgejo/default.nix b/modules/nixos/services/forgejo/default.nix
new file mode 100644
index 0000000..0f3dfc5
--- /dev/null
+++ b/modules/nixos/services/forgejo/default.nix
@@ -0,0 +1,162 @@
+# A low-ressource, full-featured git forge.
+{ config, lib, ... }:
+let
+  cfg = config.my.services.forgejo;
+in
+{
+  options.my.services.forgejo = with lib; {
+    enable = mkEnableOption "Forgejo";
+    port = mkOption {
+      type = types.port;
+      default = 3042;
+      example = 8080;
+      description = "Internal port";
+    };
+    mail = {
+      enable = mkEnableOption {
+        description = "mailer configuration";
+      };
+      host = mkOption {
+        type = types.str;
+        example = "smtp.example.com";
+        description = "Host for the mail account";
+      };
+      port = mkOption {
+        type = types.port;
+        default = 465;
+        example = 587;
+        description = "Port for the mail account";
+      };
+      user = mkOption {
+        type = types.str;
+        example = "forgejo@example.com";
+        description = "User for the mail account";
+      };
+      passwordFile = mkOption {
+        type = types.str;
+        example = "/run/secrets/forgejo-mail-password.txt";
+        description = "Password for the mail account";
+      };
+      protocol = mkOption {
+        type = types.str;
+        default = "smtps";
+        example = "smtp";
+        description = "Protocol for connection";
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = cfg.enable -> !config.my.services.gitea.enable;
+        message = ''
+          `config.my.services.forgejo` is incompatible with
+          `config.my.services.gitea`.
+        '';
+      }
+    ];
+
+    services.forgejo =
+      let
+        inherit (config.networking) domain;
+        forgejoDomain = "git.${domain}";
+      in
+      {
+        enable = true;
+
+        user = "git";
+        group = "git";
+
+        lfs.enable = true;
+
+        useWizard = false;
+
+        database = {
+          type = "postgres"; # Automatic setup
+          user = "git"; # User needs to be the same as forgejo user
+          name = "git"; # Name must be the same as user for `ensureDBOwnership`
+        };
+
+        # NixOS module uses `forgejo dump` to backup repositories and the database,
+        # but it produces a single .zip file that's not very backup friendly.
+        # I configure my backup system manually below.
+        dump.enable = false;
+
+        mailerPasswordFile = lib.mkIf cfg.mail.enable cfg.mail.passwordFile;
+
+        settings = {
+          DEFAULT = {
+            APP_NAME = "Ambroisie's forge";
+          };
+
+          server = {
+            HTTP_PORT = cfg.port;
+            DOMAIN = forgejoDomain;
+            ROOT_URL = "https://${forgejoDomain}";
+          };
+
+          mailer = lib.mkIf cfg.mail.enable {
+            ENABLED = true;
+            SMTP_ADDR = cfg.mail.host;
+            SMTP_PORT = cfg.mail.port;
+            FROM = "Forgejo <${cfg.mail.user}>";
+            USER = cfg.mail.user;
+            PROTOCOL = cfg.mail.protocol;
+          };
+
+          service = {
+            DISABLE_REGISTRATION = true;
+          };
+
+          session = {
+            # only send cookies via HTTPS
+            COOKIE_SECURE = true;
+          };
+        };
+      };
+
+    users.users.git = {
+      description = "Forgejo Service";
+      home = config.services.forgejo.stateDir;
+      useDefaultShell = true;
+      group = "git";
+      isSystemUser = true;
+    };
+    users.groups.git = { };
+
+    my.services.nginx.virtualHosts = {
+      # Proxy to Forgejo
+      git = {
+        inherit (cfg) port;
+      };
+      # Redirect `forgejo.` to actual forge subdomain
+      forgejo = {
+        redirect = config.services.forgejo.settings.server.ROOT_URL;
+      };
+    };
+
+    my.services.backup = {
+      paths = [
+        config.services.forgejo.lfs.contentDir
+        config.services.forgejo.repositoryRoot
+      ];
+    };
+
+    services.fail2ban.jails = {
+      forgejo = ''
+        enabled = true
+        filter = forgejo
+        action = iptables-allports
+      '';
+    };
+
+    environment.etc = {
+      "fail2ban/filter.d/forgejo.conf".text = ''
+        [Definition]
+        failregex = ^.*(Failed authentication attempt|invalid credentials|Attempted access of unknown user).* from <HOST>$
+        journalmatch = _SYSTEMD_UNIT=forgejo.service
+      '';
+    };
+  };
+}