docker-compose example with NodeJS and Redis

Create working dir and change to it:

$ mkdir visits
$ cd visits

Create package.json file for NodeJS:

$ cat package.json 
{
  "dependencies": {
    "express": "*",
    "redis": "2.8.0"
  },
  "scripts": {
    "start": "node index.js"
  }
}

Create an index.js file for NodeJS which uses Express and Redis:

$ cat index.js 
const express = require('express');
const redis = require('redis');
const app = express();
const client = redis.createClient({
  host: 'redis-server',
  port: 6379
  });
client.set('visits', 0);
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');
});

Create Dockerfile for NodeJS app:

$ cat Dockerfile 
FROM node:alpine
WORKDIR '/app'
COPY package.json .
RUN npm install
COPY ./index,js .
CMD ["npm", "start"]

Create docker-compose file which will start the Redis and NodeJS app:

$ cat docker-compose.yml 
version: '3'
services:
  redis-server:
    image: 'redis'
  node-app:
    restart: always
    build: .
    ports:
      - "4001:8081"

Bring up the containers:

$ docker-compose up -d

Test the application by going to the http://localhost:4001/ using the browser
After finishing testing, bring down the containers:

$ docker-compose down