diff --git a/mod-seafile-server.nix b/mod-seafile-server.nix
index e056d5e..3e40535 100644
--- a/mod-seafile-server.nix
+++ b/mod-seafile-server.nix
@@ -102,6 +102,17 @@ in
           description = "listening http port for Seahub web interface";
         };
 
+        externalPort = mkOption {
+          type = types.int;
+          default = 443;
+          description = "external port under which Seahub is reachable from the outside. Possibly the external port of a reverse proxy like nginx.";
+        };
+
+        enableTLS = mkEnableOption {
+          default = true;
+          description = "whether to use TLS and HTTPS for communication";
+        };
+
         openFirewall = mkEnableOption {
           default = true;
           description = "whether to open up the firewall ports for ccnet, seafile-server and seahub";
@@ -140,11 +151,19 @@ in
                   ${pkgs.seafile-server.ccnet-server}/bin/ccnet-init -c ./conf -n 'TEMPLATENAME' -H 'TEMPLATEHOST' -P 'TEMPLATEPORT'
                   mv ./conf/ccnet.conf{,.template}
                 fi
-                # substitute actual config values to template and symlink config file
-                ${pkgs.gnused}/bin/sed -e 's|TEMPLATENAME|${cfg.name}|g; s|TEMPLATEHOST|${cfg.domainName}|; s|TEMPLATEPORT|${toString cfg.ccnetPort}|' ./conf/ccnet.conf.template > ./conf/ccnet.conf
+
+                # generate actual ccnet config file
+                echo "[General]" > ./conf/ccnet.conf
+                grep "^ID =" ./conf/ccnet.conf.template >> ./conf/ccnet.conf
+                echo 'USER_NAME = ${cfg.name}
+                NAME = ${cfg.name}
+                # outside URL
+                SERVICE_URL = http${if cfg.enableTLS then "s" else ""}://${cfg.domainName}:${toString cfg.externalPort}
+
+                [Network]
+                Port = ${toString cfg.ccnetPort}' >> ./conf/ccnet.conf
 
                 ln -s ${pkgs.seafile-server} seafile-server
-                #${pkgs.seafile-server.ccnet-server}/bin/ccnet-init -c ./ccnet -H "${cfg.domainName}" -P ${toString cfg.ccnetPort} -n "${cfg.name}"
                 ./seafile-server/seafile-server-latest/bin/seafile-admin setup
               ''}")
             ];