npm-offline

An npm registry proxy that uses your npm cache to retrieve modules, allowing for offline access to any modules you've previously installed pretty much ever.

Super useful when you're moving around a lot and don't always have internet readily available – i.e. when travelling, or at events such as CampJS. It's nice to not need a decent WiFi connection to start a new project.

CLI Usage

Install globally using the following:

$ npm install -g npm-offline

Then you can boot up the proxy server using your newly installed npm-offline command:

$ npm-offline
http://localhost:12644/

Switching Registries

The final step is to point npm to use this registry instead of the default registry.npmjs.org. You don't want to do this permanently, or you'll never get up-to-date module versions. But by using npmrc you can quickly switch between registries. If you're not familiar with it, you can get a basic setup like so:

npm install -g npmrc
mkdir -p ~/.npmrcs
cat ~/.npmrc > ~/.npmrcs/default
cat ~/.npmrc > ~/.npmrcs/local
npmrc local
npm config set registry http://localhost:12644/

You can now switch between the local registry and the remote one using a single command:

npmrc local   # use local modules
npmrc default # use the US registry

This is the same approach advised when using the Australian/European npm mirrors and internal private registries, so it's worth familiarising yourself with it :)

Module Usage

If, for whatever reason, you want to include npm-offline as part of a larger web server you can easily do so.

route = offline(cache, registry)

Creates a route for proxying requests: where cache is your npm cache repository.

route(req, res)

var offline = require('npm-offline')
var express = require('express')
var npmconf = require('npmconf')

var app = express()

npmconf.load({}, function(err, config) {
  if (err) throw err

  app.use(offline(
      config.cache
    , 'http://registry.npmjs.org/'
  ))

  app.listen(12411, function(err) {
    if (err) throw err
  })
})

License

MIT. See LICENSE.md for details.