My_NodeLB_Project

Overview

This project demonstrates how to deploy a Node.js application in Docker containers across two backend servers, and load balance them using an NGINX reverse proxy on a separate frontend server.

Project Architecture

• VM1: 192.168.232.110: NGINX (load balancer)

• VM2: 192.168.232.111: Node.js App (port 3001)

• VM3: 192.168.232.113: Node.js App (port 3002)

Setup Instructions

Step 1: Install Docker on VM2 and VM3

sudo apt update
sudo apt install -y docker.io
sudo systemctl enable docker
sudo systemctl start docker

Step 2: Clone the project

git clone https://github.com/croyce97/My_NodeLB_Project.git

cd My_NodeLB_Project

Step 3: Build Docker image and Run the container

VM2:

• docker build -t my_node_app:v1 .
• docker run -dp 3001:3000 my_node_app:v1

VM3:

• docker build -t my_node_app:v1 .

• docker run -dp 3002:3000 my_node_app:v1

Step 4: Test each app individually on browsers (Chrome, Safari,...)

• Visit: http://192.168.232.111:3001

• Visit: http://192.168.232.113:3002

Step 5: Install NGINX on VM1

sudo apt update
sudo apt install -y nginx
sudo systemctl enable nginx

Step 6: Configure NGINX load balancing

• Create sudo nano /etc/nginx/sites-available/my_node_app.conf on VM1 using the my_node_app.conf.

• sudo ln -s /etc/nginx/sites-available/my_node_app /etc/nginx/sites-enabled/

Step 7: Log Backend IP (Upstream) in NGINX

• Open the main config file on VM1: sudo vi /etc/nginx/nginx.conf
• Inside the http { ... } block, add this custom log format:

log_format upstreamlog '$remote_addr - $remote_user [$time_local] '
                      '"$request" $status $body_bytes_sent '
                      '"$http_referer" "$http_user_agent" '
                      'to: $upstream_addr';

access_log /var/log/nginx/access.log upstreamlog;

Step 8: Add local DNS mapping for canhnq.com

VM1:

• sudo vi /etc/hosts

• Add 127.0.0.1 canhnq.com

Local Windows Machine:

• Open Notepad as Administrator
• Open the file: C:\Windows\System32\drivers\etc\hosts
• Add: 192.168.232.110 canhnq

Step 9: Start NGINX and Monitor Logs

• Start or reload NGINX:

sudo nginx -t              
sudo systemctl start nginx

• Visit: canhnq.com and reload multiple times
• Monitor access logs real time: tail -f /var/log/nginx/access.log