How to use ldapjs within a custom database connection in Auth0

Option1.js

function login(email, password, callback) {
    var ldap = require('ldapjs');

    if (!global.ldapClient) {
       // console.log('Global Client not found');
        var client = ldap.createClient({
            url: 'ldap://server:389',
            idleTimeout: 30000
        });
        client.bind('uid=admin,ou=system', 'secret', function(err) {
            if (err) callback(new Error("Error while contacting the authentication source!"));
            else {
                global.ldapClient = client;
                signInUser(email, password, callback, client);
            }

        });
    } else {
        //console.log('Global Client found');
        signInUser(email, password, callback, global.ldapClient);
    }

    function signInUser(email, password, cb, client) {
        var opts = {
            filter: '(&(|(mail=' + email + ')(uid=' + email + '))(objectClass=inetOrgPerson))',
            scope: 'sub',
            attributes: ['sn', 'cn', 'givenName', 'uid', 'mail']
        };

        var userExists = false;
        client.search('ou=users,ou=system', opts, function(err, res) {
            if (err) return cb(new Error(err.Message));

            res.on('searchEntry', function(entry) {
                userExists = true;
                client.bind(entry.object.dn, password, function(err) {
                    if (err)
                    {
                        return cb(new WrongUsernameOrPasswordError('Incorrect Username or Password'));
                    } else {
                        var profile = {};
                        profile.email = entry.object.mail;
                        profile.email_verified = true;
                        profile.family_name = entry.object.sn;
                        profile.user_id = entry.object.uid;
                        profile.given_name = entry.object.givenName;
                        profile.name = entry.object.cn;
                        profile.nickname = entry.object.uid;
                        return cb(null, profile);
                    }
                });

            });
            res.on('searchReference', function(referral) {

            });
            res.on('error', function(err) {
                return cb(new Error(err.Message));
            });
            res.on('end', function(result) {
                if (!userExists) {
                    return cb(new WrongUsernameOrPasswordError(null, 'Incorrect username or password'));
                }
            });
        });

    }

}