When you do things the way you're "supoosed" to in Rails, or Node, or super-mega-awesome-platform X, Heroky buildpacks, "just work". But every so often customization is required. Here's a quick guid to customizing an existing buildpack.
In my case I wanted to run "make" after npm in the nodejs buildpack. I think there's prolly an easier way to get the same effect, but after a while digging around online, this was the simplest thing to get the job done.
- Find the buildpack you want to extend and fork it on github
- clone the forked repo
- Edit bin/build and commit and push your changes
- Tell Heroku to use your buildpack
heroku config:set BUILDPACK_URL=https://github.com/padwasabimasala/heroku-buildpack-nodejs-with-makefile-support