feat: Add email options

sp-modules/simple-nixos-mailserver/config.nix

@@ -17,6 +17,14 @@ let
     mailserver-service-account-token-name = "mailserver-service-account-token";
     mailserver-service-account-token-fp = "/run/keys/${group}/kanidm-service-account-token"; # FIXME sync with auth module
   };
+
+  modulesConfig = builtins.mapAttrs (
+    _: value: {
+      inherit (value) hashedPasswordFile sendOnly;
+    }
+  ) config.sp.email;
+  extraDomains = lib.mapAttrsToList (_: value: value.subdomain) config.sp.email;
+  extraTargets = lib.mapAttrsToList (_: value: value.systemdTargets) config.sp.email;
 in
 lib.mkIf sp.modules.simple-nixos-mailserver.enable (
   lib.mkMerge [
@@ -62,7 +70,7 @@ lib.mkIf sp.modules.simple-nixos-mailserver.enable (
       mailserver = {
         enable = true;
         fqdn = sp.domain;
-        domains = [ sp.domain ];
+        domains = [ sp.domain ] ++ extraDomains;
         localDnsResolver = false;
 
         # A list of all login accounts. To create the password hashes, use
@@ -97,6 +105,7 @@ lib.mkIf sp.modules.simple-nixos-mailserver.enable (
               };
             }) sp.users
           )
+          // modulesConfig
         );
 
         extraVirtualAliases = {
@@ -128,6 +137,9 @@ lib.mkIf sp.modules.simple-nixos-mailserver.enable (
           postfix.serviceConfig.Slice = "simple_nixos_mailserver.slice";
           rspamd.serviceConfig.Slice = "simple_nixos_mailserver.slice";
           redis-rspamd.serviceConfig.Slice = "simple_nixos_mailserver.slice";
+
+          dovecot.wants = extraTargets;
+          dovecot2.wants = extraTargets;
         };
         slices."simple_nixos_mailserver" = {
           name = "simple_nixos_mailserver.slice";
@@ -139,7 +151,7 @@ lib.mkIf sp.modules.simple-nixos-mailserver.enable (
     (lib.mkIf is-auth-enabled {
       mailserver = {
         extraVirtualAliases = lib.mkForce { };
-        loginAccounts = lib.mkForce { };
+        loginAccounts = lib.mkForce modulesConfig;
         # LDAP is needed for Postfix to query Kanidm about email address ownership.
         # LDAP is needed for Dovecot also.
         ldap = {

sp-modules/simple-nixos-mailserver/options.nix

@@ -1,4 +1,4 @@
-{ lib, ... }:
+{ config, lib, ... }:
 {
   options.selfprivacy.modules.simple-nixos-mailserver = {
     enable =
@@ -34,4 +34,54 @@
         };
       };
   };
+
+  options.sp.email = with lib; mkOption {
+    type = types.attrsOf (
+      types.submodule (
+        { name, ... }: {
+          options = {
+            subdomain = mkOption {
+              type = with types; strMatching "[A-Za-z0-9][A-Za-z0-9\-]{0,61}[A-Za-z0-9]";
+              example = "myservice";
+              default = config.sp.domain;
+              description = "Email subdomain";
+            };
+
+            systemdTargets = mkOption {
+              type = with types; listOf strMatchig "[a-zA-Z0-9@%:_.\-]+[.](service|socket|device|mount|automount|swap|target|path|timer|scope|slice)";
+              default = [];
+              example = [ "generate-mastodon-email-password.service" ];
+              description = "Systemd target which generates password file.";
+            };
+
+            sendOnly = mkOption {
+              type = with types; bool;
+              default = true;
+              example = "false";
+              description = "Specifies if the account should be a send-only account. Emails sent to send-only accounts will be rejected.";
+            };
+
+            hashedPasswordFile = mkOption {
+              type = with types; str;
+              example = "/run/keys/mastodon/email_password";
+              description = "Path where a file containing password hash located.";
+            };
+          };
+        }
+      )
+    );
+
+    description = ''
+      Don't use this option to create regular users!!!
+
+      This option gives modules possibility to create mailboxes to send emails, e.g. notifications or reminders.
+    '';
+
+    example = {
+      "noreply@mastodon.example.tld" = {
+        hashedPasswordFile = "/run/keys/mastodon/email_password";
+        systemdTargets = [ "generate-mastodon-email-password.service" ];
+      };
+    };
+  };
 }