nixos/disnix: reorder startup to take MongoDB and InfluxDB into account, add option to add Disnix profile to the system PATH

nixos/modules/services/misc/disnix.nix

@@ -34,6 +34,14 @@ in
         defaultText = "pkgs.disnix";
       };
 
+      enableProfilePath = mkEnableOption "exposing the Disnix profiles in the system's PATH";
+
+      profiles = mkOption {
+        type = types.listOf types.string;
+        default = [ "default" ];
+        example = [ "default" ];
+        description = "Names of the Disnix profiles to expose in the system's PATH";
+      };
     };
 
   };
@@ -44,6 +52,7 @@ in
     dysnomia.enable = true;
 
     environment.systemPackages = [ pkgs.disnix ] ++ optional cfg.useWebServiceInterface pkgs.DisnixWebService;
+    environment.variables.PATH = lib.optionals cfg.enableProfilePath (map (profileName: "/nix/var/nix/profiles/disnix/${profileName}/bin" ) cfg.profiles);
 
     services.dbus.enable = true;
     services.dbus.packages = [ pkgs.disnix ];
@@ -68,7 +77,8 @@ in
           ++ optional config.services.postgresql.enable "postgresql.service"
           ++ optional config.services.tomcat.enable "tomcat.service"
           ++ optional config.services.svnserve.enable "svnserve.service"
-          ++ optional config.services.mongodb.enable "mongodb.service";
+          ++ optional config.services.mongodb.enable "mongodb.service"
+          ++ optional config.services.influxdb.enable "influxdb.service";
 
         restartIfChanged = false;