Merge pull request #76739 from symphorien/mail_plugins

nixos/dovecot: add an option to enable mail_plugins

nixos/modules/services/mail/dovecot.nix

@@ -14,9 +14,24 @@ let
       base_dir = ${baseDir}
       protocols = ${concatStringsSep " " cfg.protocols}
       sendmail_path = /run/wrappers/bin/sendmail
+      # defining mail_plugins must be done before the first protocol {} filter because of https://doc.dovecot.org/configuration_manual/config_file/config_file_syntax/#variable-expansion
+      mail_plugins = $mail_plugins ${concatStringsSep " " cfg.mailPlugins.globally.enable}
     ''
 
-    (if cfg.sslServerCert == null then ''
+    (
+      concatStringsSep "\n" (
+        mapAttrsToList (
+          protocol: plugins: ''
+            protocol ${protocol} {
+              mail_plugins = $mail_plugins ${concatStringsSep " " plugins.enable}
+            }
+          ''
+        ) cfg.mailPlugins.perProtocol
+      )
+    )
+
+    (
+      if cfg.sslServerCert == null then ''
         ssl = no
         disable_plaintext_auth = no
       '' else ''
@@ -25,7 +40,8 @@ let
         ${optionalString (cfg.sslCACert != null) ("ssl_ca = <" + cfg.sslCACert)}
         ssl_dh = <${config.security.dhparams.params.dovecot2.path}
         disable_plaintext_auth = yes
-    '')
+      ''
+    )
 
     ''
       default_internal_user = ${cfg.user}
@@ -45,7 +61,8 @@ let
       }
     ''
 
-    (optionalString cfg.enablePAM ''
+    (
+      optionalString cfg.enablePAM ''
         userdb {
           driver = passwd
         }
@@ -54,25 +71,30 @@ let
           driver = pam
           args = ${optionalString cfg.showPAMFailure "failure_show_msg=yes"} dovecot2
         }
-    '')
+      ''
+    )
 
-    (optionalString (cfg.sieveScripts != {}) ''
+    (
+      optionalString (cfg.sieveScripts != {}) ''
         plugin {
           ${concatStringsSep "\n" (mapAttrsToList (to: from: "sieve_${to} = ${stateDir}/sieve/${to}") cfg.sieveScripts)}
         }
-    '')
+      ''
+    )
 
-    (optionalString (cfg.mailboxes != []) ''
+    (
+      optionalString (cfg.mailboxes != []) ''
         protocol imap {
           namespace inbox {
             inbox=yes
             ${concatStringsSep "\n" (map mailboxConfig cfg.mailboxes)}
           }
         }
-    '')
+      ''
+    )
 
-    (optionalString cfg.enableQuota ''
+    (
-      mail_plugins = $mail_plugins quota
+      optionalString cfg.enableQuota ''
         service quota-status {
           executable = ${dovecotPkg}/libexec/dovecot/quota-status -p postfix
           inet_listener {
@@ -81,10 +103,6 @@ let
           client_limit = 1
         }
 
-      protocol imap {
-        mail_plugins = $mail_plugins imap_quota
-      }
-
         plugin {
           quota_rule = *:storage=${cfg.quotaGlobalPerUser}
           quota = maildir:User quota # per virtual mail user quota # BUG/FIXME broken, we couldn't get this working
@@ -93,7 +111,8 @@ let
           quota_status_overquota = "552 5.2.2 Mailbox is full"
           quota_grace = 10%%
         }
-    '')
+      ''
+    )
 
     cfg.extraConfig
   ];
@@ -160,7 +179,7 @@ in
 
     protocols = mkOption {
       type = types.listOf types.str;
-      default = [ ];
+      default = [];
       description = "Additional listeners to start when Dovecot is enabled.";
     };
 
@@ -183,6 +202,43 @@ in
       description = "Additional entries to put verbatim into Dovecot's config file.";
     };
 
+    mailPlugins =
+      let
+        plugins = hint: types.submodule {
+          options = {
+            enable = mkOption {
+              type = types.listOf types.str;
+              default = [];
+              description = "mail plugins to enable as a list of strings to append to the ${hint} <literal>$mail_plugins</literal> configuration variable";
+            };
+          };
+        };
+      in
+        mkOption {
+          type = with types; submodule {
+            options = {
+              globally = mkOption {
+                description = "Additional entries to add to the mail_plugins variable for all protocols";
+                type = plugins "top-level";
+                example = { enable = [ "virtual" ]; };
+                default = { enable = []; };
+              };
+              perProtocol = mkOption {
+                description = "Additional entries to add to the mail_plugins variable, per protocol";
+                type = attrsOf (plugins "corresponding per-protocol");
+                default = {};
+                example = { imap = [ "imap_acl" ]; };
+              };
+            };
+          };
+          description = "Additional entries to add to the mail_plugins variable, globally and per protocol";
+          example = {
+            globally.enable = [ "acl" ];
+            perProtocol.imap.enable = [ "imap_acl" ];
+          };
+          default = { globally.enable = []; perProtocol = {}; };
+        };
+
     configFile = mkOption {
       type = types.nullOr types.path;
       default = null;
@@ -310,22 +366,28 @@ in
       ++ optional cfg.enablePop3 "pop3"
       ++ optional cfg.enableLmtp "lmtp";
 
+    services.dovecot2.mailPlugins = mkIf cfg.enableQuota {
+      globally.enable = [ "quota" ];
+      perProtocol.imap.enable = [ "imap_quota" ];
+    };
+
     users.users = {
       dovenull =
-        { uid = config.ids.uids.dovenull2;
+        {
+          uid = config.ids.uids.dovenull2;
           description = "Dovecot user for untrusted logins";
           group = "dovenull";
         };
     } // optionalAttrs (cfg.user == "dovecot2") {
       dovecot2 =
-         { uid = config.ids.uids.dovecot2;
+        {
+          uid = config.ids.uids.dovecot2;
           description = "Dovecot user";
           group = cfg.group;
         };
     } // optionalAttrs (cfg.createMailUser && cfg.mailUser != null) {
       ${cfg.mailUser} =
-        { description = "Virtual Mail User"; } //
+        { description = "Virtual Mail User"; } // optionalAttrs (cfg.mailGroup != null)
-        optionalAttrs (cfg.mailGroup != null)
           { group = cfg.mailGroup; };
     };
 
@@ -334,7 +396,7 @@ in
     } // optionalAttrs (cfg.group == "dovecot2") {
       dovecot2.gid = config.ids.gids.dovecot2;
     } // optionalAttrs (cfg.createMailUser && cfg.mailGroup != null) {
-      ${cfg.mailGroup} = { };
+      ${cfg.mailGroup} = {};
     };
 
     environment.etc."dovecot/modules".source = modulesDir;
@@ -363,7 +425,9 @@ in
         rm -rf ${stateDir}/sieve
       '' + optionalString (cfg.sieveScripts != {}) ''
         mkdir -p ${stateDir}/sieve
-        ${concatStringsSep "\n" (mapAttrsToList (to: from: ''
+        ${concatStringsSep "\n" (
+        mapAttrsToList (
+          to: from: ''
             if [ -d '${from}' ]; then
               mkdir '${stateDir}/sieve/${to}'
               cp -p "${from}/"*.sieve '${stateDir}/sieve/${to}'
@@ -371,7 +435,9 @@ in
               cp -p '${from}' '${stateDir}/sieve/${to}'
             fi
             ${pkgs.dovecot_pigeonhole}/bin/sievec '${stateDir}/sieve/${to}'
-        '') cfg.sieveScripts)}
+          ''
+        ) cfg.sieveScripts
+      )}
         chown -R '${cfg.mailUser}:${cfg.mailGroup}' '${stateDir}/sieve'
       '';
     };
@@ -379,17 +445,21 @@ in
     environment.systemPackages = [ dovecotPkg ];
 
     assertions = [
-      { assertion = intersectLists cfg.protocols [ "pop3" "imap" ] != [];
+      {
+        assertion = intersectLists cfg.protocols [ "pop3" "imap" ] != [];
         message = "dovecot needs at least one of the IMAP or POP3 listeners enabled";
       }
-      { assertion = (cfg.sslServerCert == null) == (cfg.sslServerKey == null)
+      {
+        assertion = (cfg.sslServerCert == null) == (cfg.sslServerKey == null)
         && (cfg.sslCACert != null -> !(cfg.sslServerCert == null || cfg.sslServerKey == null));
         message = "dovecot needs both sslServerCert and sslServerKey defined for working crypto";
       }
-      { assertion = cfg.showPAMFailure -> cfg.enablePAM;
+      {
+        assertion = cfg.showPAMFailure -> cfg.enablePAM;
         message = "dovecot is configured with showPAMFailure while enablePAM is disabled";
       }
-      { assertion = cfg.sieveScripts != {} -> (cfg.mailUser != null && cfg.mailGroup != null);
+      {
+        assertion = cfg.sieveScripts != {} -> (cfg.mailUser != null && cfg.mailGroup != null);
         message = "dovecot requires mailUser and mailGroup to be set when sieveScripts is set";
       }
     ];