Dockerizing a NodeJS , Express, Redis with Nginx Proxy using Docker Compose

With over 18,700 stars, 2,900 forks, awesome-compose is a popular Docker repository that provides a starting point for how to integrate different services using a Compose file and to manage their deployment with Docker Compose. This project is maintained by Docker, Inc and open for the community to contribute and submit their compose file.

Available Categories

The setups provided currently in the awesome-compose repository fit mainly in two categories:

Application skeletons

It is useful for kicking off project development. We can find different application skeletons with multiple services already wired together and ready to be launched with docker-compose;

Open-source software stacks

These setups are not meant for production. They are intended mostly for personal/home use or simply for developers to get familiar with them within their local dev environment.

Here’s a quick glimpse of the awesome-compose repository:

In this tutorial, you will see how to containerise a NodeJS web application with Redis database and Nginx as a reverse proxy in front of NodeJS app using Docker. We are going to build the following project structure:

Project structure

.
├── docker-compose.yml
├── nginx
│   ├── Dockerfile
│   └── nginx.conf
├── web
│   ├── Dockerfile
│   ├── package.json
│   └── server.js
├── web1
│   ├── Dockerfile
│   ├── package.json
│   └── server.js
└── web2
    ├── Dockerfile
    ├── package.json
    └── server.js

4 directories, 12 files

Prerequisite:

– Install Docker Desktop

Visit https://docs.docker.com/desktop/mac/install/ to setup Docker Desktop for Mac or Windows on your local system.

ℹ️ INFO

Docker Desktop comes with Docker compose installed by default, hence you don’t need to install it separately.

Step 1. Create a Docker compose file

Create an empty file with the below content and save it by name – “docker-compose.yml”

version: '3.9'
services:
  redis:
    image: 'redis:alpine'
    ports:
      - '6379:6379'
  web1:
    restart: on-failure
    build: ./web1
    ports:
      - '81:5000'
  web2:
    restart: on-failure
    build: ./web2
    ports:
      - '82:5000'
  nginx:
    build: ./nginx
    ports:
    - '80:80'
    depends_on:
    - web1
    - web2

The compose file defines an application with four services redis, web, web1 and web2.
When deploying the application, docker-compose maps port 80 of the web service container to port 80 of the host as specified in the file.

ℹ️ INFO

Redis runs on port 6379 by default. Make sure you don’t run another instance of Redis on your system or port 6379 on the host is not being used by another container, otherwise the port should be changed.

Step 2. Create an nginx directory and add the below files:

File: nginx/nginx.conf


upstream loadbalancer {
  server web1:5000;
  server web2:5000;
}

server {
  listen 80;
  server_name localhost;
  location / {
    proxy_pass http://loadbalancer;
  }
}

File: Dockerfile

FROM nginx:1.21.6
RUN rm /etc/nginx/conf.d/default.conf
COPY nginx.conf /etc/nginx/conf.d/default.conf

Step 3. Create a web directory and add the below files:

File: web/Dockerfile

FROM node:14.17.3-alpine3.14

WORKDIR /usr/src/app

COPY ./package.json ./
RUN npm install
COPY ./server.js ./

CMD ["npm","start"]

File: web/package.json

"name": "web",
  "version": "1.0.0",
  "description": "Running Node.js and Express.js on Docker",
  "main": "server.js",
  "scripts": {
    "start": "node server.js"
  },
  "dependencies": {
    "express": "^4.17.2",
    "redis": "3.1.2"
  },
  "author": "",
  "license": "MIT"
}

File: web/server.js

const express = require('express');
const redis = require('redis');
const app = express();
const redisClient = redis.createClient({
  host: 'redis',
  port: 6379
});

app.get('/', function(req, res) {
    redisClient.get('numVisits', function(err, numVisits) {
        numVisitsToDisplay = parseInt(numVisits) + 1;
        if (isNaN(numVisitsToDisplay)) {
            numVisitsToDisplay = 1;
        }
        res.send('Number of visits is: ' + numVisitsToDisplay);
        numVisits++;
        redisClient.set('numVisits', numVisits);
    });
});

app.listen(5000, function() {
    console.log('Web application is listening on port 5000');
});

File: server.js

const express = require('express');
const redis = require('redis');
const app = express();
const redisClient = redis.createClient({
  host: 'redis',
  port: 6379
});


app.get('/', function(req, res) {
    redisClient.get('numVisits', function(err, numVisits) {
        numVisitsToDisplay = parseInt(numVisits) + 1;
        if (isNaN(numVisitsToDisplay)) {
            numVisitsToDisplay = 1;
        }
        res.send('web1: Total number of visits is: ' + numVisitsToDisplay);
        numVisits++;
        redisClient.set('numVisits', numVisits);
    });
});

app.listen(5000, function() {
    console.log('Web app is listening on port 5000');
});

File: package.json

{
  "name": "web1",
  "version": "1.0.0",
  "description": "Running Node.js and Express.js on Docker",
  "main": "server.js",
  "scripts": {
    "start": "node server.js"
  },
  "dependencies": {
    "express": "^4.17.2",
    "redis": "3.1.2"
  },
  "author": "",
  "license": "MIT"
}

Step 5. Deploy the application

Let us deploy the full-fledged app using docker-compose

$ docker-compose up -d

Creating nginx-nodejs-redis_redis_1 ... done
Creating nginx-nodejs-redis_web1_1  ... done
Creating nginx-nodejs-redis_web2_1  ... done
Creating nginx-nodejs-redis_nginx_1 ... done

Expected result

Listing containers must show three containers running and the port mapping as below:

docker-compose ps
           Name                        Command              State           Ports         
------------------------------------------------------------------------------------------
nginx-nodejs-redis_nginx_1   /docker-entrypoint.sh ngin     Up      0.0.0.0:80->80/tcp    
                             ...                                                          
nginx-nodejs-redis_redis_1   docker-entrypoint.sh redis     Up      0.0.0.0:6379->6379/tcp
                             ...                                                          
nginx-nodejs-redis_web1_1    docker-entrypoint.sh npm       Up      0.0.0.0:81->5000/tcp  
                             start                                                        
nginx-nodejs-redis_web2_1    docker-entrypoint.sh npm       Up      0.0.0.0:82->5000/tcp  
                             start

Step 6. Testing the app

After the application starts, navigate to http://localhost:80 in your web browser or run:

curl localhost:80
curl localhost:80
web1: Total number of visits is: 1

curl localhost:80
web1: Total number of visits is: 2

$ curl localhost:80
web2: Total number of visits is: 3

$ curl localhost:80
web2: Total number of visits is: 4

Stop and remove the containers

$ docker-compose down

Step 7. Monitoring Redis keys

If you want to monitor the Redis keys, you can use monitor command. Install redis-client in your Mac system using

brew install redis

and then directly connect to Redis container by issuing the below command:

% redis-cli
127.0.0.1:6379> monitor
OK
1646485507.290868 [0 172.24.0.2:34330] "get" "numVisits"
1646485507.309070 [0 172.24.0.2:34330] "set" "numVisits" "5"
1646485509.228084 [0 172.24.0.2:34330] "get" "numVisits"
1646485509.241762 [0 172.24.0.2:34330] "set" "numVisits" "6"
1646485509.619369 [0 172.24.0.4:52082] "get" "numVisits"
1646485509.629739 [0 172.24.0.4:52082] "set" "numVisits" "7"
1646485509.990926 [0 172.24.0.2:34330] "get" "numVisits"
1646485509.999947 [0 172.24.0.2:34330] "set" "numVisits" "8"
1646485510.270934 [0 172.24.0.4:52082] "get" "numVisits"
1646485510.286785 [0 172.24.0.4:52082] "set" "numVisits" "9"
1646485510.469613 [0 172.24.0.2:34330] "get" "numVisits"
1646485510.480849 [0 172.24.0.2:34330] "set" "numVisits" "10"
1646485510.622615 [0 172.24.0.4:52082] "get" "numVisits"
1646485510.632720 [0 172.24.0.4:52082] "set" "numVisits" "11"