[update] Use environment variables defined by user.

Instead of using docker automatic variables to access multilevel, let the user
set these variables, this makes the startup process more user friendly.
'use strict';
var net = require('net');
var multilevel = require('multilevel');

var db = multilevel.client();
db._separator = '~';
db._rangeLowerLimit = '!';
db._rangeUpperLimit = '~';
db._makeKey = makeKey;


var conn = net.connect({
  port: parseInt(process.env.LVLDB_PORT),
  host: process.env.LVLDB_HOST
});

console.log('Connect to multilevel through ' + process.env.LVLDB_HOST + ':' + process.env.LVLDB_PORT);
conn.pipe(db.createRpcStream()).pipe(conn);

module.exports = exports = db;

/**
 * makeKey -- Create a key prefix to be used by a given constructor.
 *
 * @param constructor{String} -- constructor function.
 * @return {String} -- prefix key.
 */
function makeKey(constructor) {
  return constructor.name.toLowerCase() + db._separator;
}

'use strict';
var net = require('net');
var multilevel = require('multilevel');

var db = multilevel.client();
db._separator = '~';
db._rangeLowerLimit = '!';
db._rangeUpperLimit = '~';
db._makeKey = makeKey;


var conn = net.connect({
  port: parseInt(process.env.DB_PORT_3001_TCP_PORT),
  host: process.env.DB_PORT_3001_TCP_ADDR
});

console.log('Connect to multilevel through ' + process.env.DB_PORT_3001_TCP_ADDR + ':' + process.env.DB_PORT_3001_TCP_PORT);
conn.pipe(db.createRpcStream()).pipe(conn);

module.exports = exports = db;

/**
 * makeKey -- Create a key prefix to be used by a given constructor.
 *
 * @param constructor{String} -- constructor function.
 * @return {String} -- prefix key.
 */
function makeKey(constructor) {
  return constructor.name.toLowerCase() + db._separator;
}
