Node_modules folder and Git


Today I have created a repository of node.js website or server as you wish.
In general while learning I used to store modules for example mongodb, socket.io in node_modules and it was by default. I want to make it work on Openshift. When I install modules using

npm install 'module name'

It installs 'em in workingdirectory/node_modules.
But when I clone repository and try to see what's changed or to push something or in this case that folder using

git status

It says that the working directory is clean and nothing is changed though I a have installed some modules.
Is there something different to make this work on Openshift? And how if I'm not able to push modules?