Node.js - do I need to reinstall all the modules on the production server when deploying the Node.js app

Question

I have developed my first Node.js pp. For now, it just sits on my laptop.

During development I had to install some modules:

npm install socket.io
npm install [email protected]
npm install iniparser
npm install js-yaml
npm install nodemailer

I have installed all of them "per-project", not globally.

The directory of my project looks like this (my code is all in push_server.js):

|
|--- push_server.js
|
|--- node_modules
     |--- iniparser
     |--- js-yaml
     |--- mysql
     |--- socket.io
     |--- nodemailer

Now I want to push this project to the production server.

My question is: can I upload the whole codebase (including installed modules) or should I upload just the code of my app and re-install the modules one-by-one on the server?

Note: my dev machine runs Ubuntu 10.04, the production server runs CentOS 5.3

I think all those modules are made up of js files only, therefore it should be allright.
However, is it possible that a module installed by npm compiles some code on the local machine, therefore that code is likely not to work on another machine. Also, how can I know whether a module does that?

Hope the question is not too silly - I have just started with Node.js.

Thanks.

Answer 1

You should definitely copy node_modules if possible.

If you re-download them at the server, you run a risk of getting slightly different versions of the modules in use. Even if you require a strict module version X, that module can again have wildcard dependencies to other modules Y Z. This means that if Y is updated and you publish to the server, it will now run using different code for Y than what you used for your local testing and validation.

In some cases you may not even have a required module available at deployment time, because the author has decided to de-publish the package for whatever reason.