title: Nexus, npm and proxies.. oh my
body: <p>Ok, so I am working in an environment whereby access to download archive files from external sites is restricted to certain users by the corporate firewall. </p>
  
  <p>What I want to achieve is to setup a local npm repository and have "approved" repositories available for all the developers. </p>
  
  <p>I looked at nexus and see that it is possible to add a proxy repo to <a href="https://registry.npmjs.org" rel="nofollow">https://registry.npmjs.org</a>, and I can see that I can add HTTP proxy credentials. </p>
  
  <p>This gets me partially there, as developers can now access anything they want from npmjs as its proxied through a user that has the required access. The problem is, I don't want to allow anyone to get anything, I only want nexus to go to npmjs and keep a local copy for a select few users, everyone else should be able to get the packages form the local cache, but if it ain't there then not proxy to npmjs. </p>
  
  <p>Any ideas how I can achieve this?</p>