How to sort (by whatever key) BibTex entries in `.bib` file?

I work with LaTeX and do versioning with Git. For bibliography management I use [Mendeley](www.mendeley.com). The problem is that each time Mendeley synchronizes it's .bib exports, they are in different order, what makes bibliography versioning much harder. My idea is to sort BibTex entries in .bib file, each time before commit. Could you help me, how to do this in smart (short&sweet) way ? :) P.S. I can run this routine manually. I do not need git integration. I just want program/script to sort .bib file.