There are many ways to extend `verdaccio`, currently we only support `authentication plugins`
## Authentication Plugins
This section will describe how it looks like a Verdaccio plugin in a ES5 way. Basically we have to return an object with a single method called `authenticate` that will recieve 3 arguments (`user, password, callback`). Once the authentication has been executed there is 2 options to give a response to `verdaccio`.
##### OnError
Either something bad happened or auth was unsuccessful.
```
callback(null, false)
```
##### OnSuccess
The auth was successful.
`groups` is an array of strings where the user is part of.
```
callback(null, groups);
```
### Example
```javascript
function Auth(config, stuff) {
var self = Object.create(Auth.prototype);
self._users = {};
// config for this module
self._config = config;
// verdaccio logger
self._logger = stuff.logger;
// pass verdaccio logger to ldapauth
self._config.client_options.log = stuff.logger;
return self;
}
Auth.prototype.authenticate = function (user, password, callback) {
var LdapClient = new LdapAuth(self._config.client_options);
....
LdapClient.authenticate(user, password, function (err, ldapUser) {
