nixos/mlmmj: fix newline problems with multiple lists

- Insert newlines into list configurations
- Move list maintence to a timer
- Create missing directories at profile activation

nixos/modules/services/mail/mlmmj.nix

@@ -4,6 +4,8 @@ with lib;
 
 let
 
+  concatMapLines = f: l: lib.concatStringsSep "\n" (map f l);
+
   cfg = config.services.mlmmj;
   stateDir = "/var/lib/mlmmj";
   spoolDir = "/var/spool/mlmmj";
@@ -16,13 +18,24 @@ let
   listAddress = domain: list: "${list}@${domain}";
   customHeaders = domain: list: [ "List-Id: ${list}" "Reply-To: ${list}@${domain}" ];
   footer = domain: list: "To unsubscribe send a mail to ${list}+unsubscribe@${domain}";
-  createList = d: l: ''
-    ${pkgs.coreutils}/bin/mkdir -p ${listCtl d l}
-    echo ${listAddress d l} > ${listCtl d l}/listaddress
-    echo "${lib.concatStringsSep "\n" (customHeaders d l)}" > ${listCtl d l}/customheaders
-    echo ${footer d l} > ${listCtl d l}/footer
-    echo ${subjectPrefix l} > ${listCtl d l}/prefix
-  '';
+  createList = d: l:
+    let ctlDir = listCtl d l; in
+    ''
+      for DIR in incoming queue queue/discarded archive text subconf unsubconf \
+                 bounce control moderation subscribers.d digesters.d requeue \
+                 nomailsubs.d
+      do
+             mkdir -p '${listDir d l}'/"$DIR"
+      done
+      ${pkgs.coreutils}/bin/mkdir -p ${ctlDir}
+      echo ${listAddress d l} > '${ctlDir}/listaddress'
+      [ ! -e ${ctlDir}/customheaders ] && \
+          echo "${lib.concatStringsSep "\n" (customHeaders d l)}" > '${ctlDir}/customheaders'
+      [ ! -e ${ctlDir}/footer ] && \
+          echo ${footer d l} > '${ctlDir}/footer'
+      [ ! -e ${ctlDir}/prefix ] && \
+          echo ${subjectPrefix l} > '${ctlDir}/prefix'
+    '';
 in
 
 {
@@ -63,6 +76,16 @@ in
         description = "The collection of hosted maillists";
       };
 
+      maintInterval = mkOption {
+        type = types.str;
+        default = "20min";
+        description = ''
+          Time interval between mlmmj-maintd runs, see
+          <citerefentry><refentrytitle>systemd.time</refentrytitle>
+          <manvolnum>7</manvolnum></citerefentry> for format information.
+        '';
+      };
+
     };
 
   };
@@ -93,7 +116,7 @@ in
         mlmmj unix - n n - - pipe flags=ORhu user=mlmmj argv=${pkgs.mlmmj}/bin/mlmmj-receive -F -L ${spoolDir}/$nexthop
       '';
 
-      extraAliases = concatMapStrings (alias cfg.listDomain) cfg.mailLists;
+      extraAliases = concatMapLines (alias cfg.listDomain) cfg.mailLists;
 
       extraConfig = ''
         transport_maps = hash:${stateDir}/transports
@@ -107,17 +130,15 @@ in
     system.activationScripts.mlmmj = ''
           ${pkgs.coreutils}/bin/mkdir -p ${stateDir} ${spoolDir}/${cfg.listDomain}
           ${pkgs.coreutils}/bin/chown -R ${cfg.user}:${cfg.group} ${spoolDir}
-          ${lib.concatMapStrings (createList cfg.listDomain) cfg.mailLists}
-          echo ${lib.concatMapStrings (virtual cfg.listDomain) cfg.mailLists} > ${stateDir}/virtuals
-          echo ${lib.concatMapStrings (transport cfg.listDomain) cfg.mailLists} > ${stateDir}/transports
+          ${concatMapLines (createList cfg.listDomain) cfg.mailLists}
+          echo "${concatMapLines (virtual cfg.listDomain) cfg.mailLists}" > ${stateDir}/virtuals
+          echo "${concatMapLines (transport cfg.listDomain) cfg.mailLists}" > ${stateDir}/transports
           ${pkgs.postfix}/bin/postmap ${stateDir}/virtuals
           ${pkgs.postfix}/bin/postmap ${stateDir}/transports
       '';
 
     systemd.services."mlmmj-maintd" = {
       description = "mlmmj maintenance daemon";
-      wantedBy = [ "multi-user.target" ];
-
       serviceConfig = {
         User = cfg.user;
         Group = cfg.group;
@@ -125,6 +146,11 @@ in
       };
     };
 
+    systemd.timers."mlmmj-maintd" = {
+      description = "mlmmj maintenance timer";
+      timerConfig.OnUnitActiveSec = cfg.maintInterval;
+      wantedBy = [ "timers.target" ];
+    };
   };
 
 }