Node app server for Docker container with Redis

index.js

const express = require('express');
const redis = require('redis');
client.set('visits', 0);

const app = express();
const client = redis.createClient();

app.get('/', (req, res) => {
  client.get('visits', (err, visits) => {
    res.send('Number of visits is' + visits);
    client.set('visits', parseInt(visits) + 1);
  });
});

app.listen(8081, () => {
  console.log('Listening on port 8081');
});