If you use the latest Awesome 3.5 or newer, then you already have Menubar. Press Modkey-P to see it.
This version is for Awesome 3.4.x.
Dmenu-like menu for Awesome WM.
Parses folders like /usr/share/applications for .desktop files. Shows icons for categories and applications. Completely keyboard-controllable.
See http://awesome.naquadah.org/wiki/Menubar . Installation guide, screenshots and detailed description can be also found there.