npm_lazy

A lazy local cache for npm

Why?

npm can be slow, down or return random errors if you have large deploys
npm_lazy caches packages on your local network, making things faster and more predictable
If 100 servers request the same package metadata at the same time, npm_lazy makes sure that (at most) only one request goes out to the npm registry.
No database to install, replicate or manage. Data is stored under ./db/ as JSON and tar files.
Lazy caching: When a package is requested the first time, it is cached locally. No explicit need to manage packages or replication.
Metadata is expired periodically (default: 1 hour) so that the latest versions of packages are fetched.

+1 on Github

Other stuff

Clone

Installing

git clone git://github.com/mixu/npm_push.git

Edit configuration in config.js (e.g. port and external URL) and start the server:

node server.js

Pointing npm to npm_lazy

To temporarily set the registry:

npm --registry http://localhost:8080/ install socket.io

To permanently set the registry via command line:

 npm config set registry http://localhost:8080/

To permanently set the registry via config file, in ~/.npmrc:

registry = http://localhost:8080/

For more info, see "npm help config" and "npm help registry".

Configuration

module.exports = {
  // directory to store cached packages (full path)
  cacheDirectory: __dirname+'/db/',
  // maximum age before an index is refreshed from npm
  cacheAge: 60 * 60 * 1000,
  // external url to npm_lazy, no trailing /
  externalUrl: 'http://localhost:8080',
  // bind port and host
  port: 8080,
  host: 'localhost'
};

Caching logic

When a resource is requested:

Anything that we don't have locally gets fetched from registry.npmjs.org on demand.
Metadata is updated when the resource is requested the first time after a restart, and if the resource is requested an hour later (which is the max age for package metadata).