How to use the pm2.Client function in pm2

let fs = require('fs'),
    path = require('path'),
    async = require('async'),
    mkdirp = require('mkdirp'),
    colors = require('colors'),
    pm2 = require('pm2'),
    pm2cst = require('pm2/constants.js'),
    pm2prepare = require('pm2/lib/Common.js').prepareAppConf,
    // Client is pm2's RPC daemon, we have to use it to get
    // some custom behavior that is not exposed by pm2's CLI.
    Client = pm2.Client,
    exec = require('child_process').exec,
    Emitter = require('events').EventEmitter,
    debug = require('debug')('api')

var conf = require('./conf'),
    ERRORS = require('./errors'),
    formatter = require('./formatter'),
    hookTemplate = fs.readFileSync(__dirname + '/../hooks/post-receive', 'utf-8')

// Load config data
var globalConfigPath = conf.path,
    webInterfaceId = conf.webId,
    globalConfig = readJSON(globalConfigPath)

upgradeConf()

pm2.connect(function () {
    api.emit('ready');
    Client = pm2.Client;
})

'use strict';

const pm2 = require('pm2');
const pmx = require('pmx');
const packageJSON =  require('./package');
const conf = pmx.initModule();
const elasticLibModule = require('./libs/elasticsearch');
const elasticLib = new elasticLibModule(conf.elasticsearch_host, conf.elasticsearch_index);
/**
 * Change default host to elasticsearch : pm2 set pm2-elasticlogs:elasticsearch_host 'http://localhost:9200'
 *
 *   Start module in development mode
 *          $ pm2 install .
 */

pm2.Client.launchBus(function(err, bus) {
    if(err)
        return console.error(err);
    bus.on('log:*', function(type, packet) {
        if ((conf.app_name != 'all' && conf.app_name && conf.app_name != packet.process.name) || packet.process.name === packageJSON.name) return false;

        if (typeof(packet.data) == 'string')
            packet.data = packet.data.replace(/(\r\n|\n|\r)/gm,'');
        elasticLib.add({
            message : packet.data,
            application : packet.process.name,
            process_id : packet.process.pm_id,
        }).catch((e) => {console.error(e)});
    });
});