[deployment] How do I install package.json dependencies in the current directory using npm

I have a web app: fooapp. I have a package.json in the root. I want to install all the dependencies in a specific node_modules directory. How do I do this?

What I want

Lets say I have two widget dependencies. I want to end up with a directory structure like this:

node_modules/
  widgetA
  widgetB
fooapp/
  package.js
  lib
  ..

What I get

when I run npm install fooapp/ I get this:

node_modules/
  fooapp/
    node_modules/
      widgetA
      widgetB
    package.js
    lib/
    ..
fooapp/
  package.js
  lib/
  ..

npm makes a copy of my app directory in the node_modules dir and installs the packages inside another node_modules directory.

I understand this makes sense for installing a package. But I don't require() my web app inside of something else, I run it directly. I'm looking for a simple way to install my dependencies into a specific node_modules directory.

In my case I need to do

sudo npm install  

my project is inside /var/www so I also need to set proper permissions.

Just execute

sudo npm i --save

That's all