Load balancing with Nginx

Simple example to show how to config Nginx load balancer.

Description

Node JS, Nginx, Docker

Getting Started

Dependencies

• Docker

Installing

1. Build Node application Docker image

 docker build -t node_js_backend:1.0 .

2. Verify Node JS image

 docker images

3. Run 3 container based same image

docker run -d -p 4001:4000 --name backend1 -e server=backend_1 node_js_backend:1.0
docker run -d -p 4002:4000 --name backend2 -e server=backend_2 node_js_backend:1.0
docker run -d -p 4003:4000 --name backend3 -e server=backend_3 node_js_backend:1.0

4. Verify backend containers

 docker ps

5. Edit Nginx configuration file: /gateway/nginx.conf. You should inspect IP address of localhost after that you must write into the "nginx.conf" file. Just copy the first IP address.

hostname -I

6. Build Nginx image

docker build -t api_gateway:1.0 .

7. Verify Nginx image

 docker images

8. Run Nginx container

docker run -d -p 87:80 --name load_balancer api_gateway:1.0

Executing program

• You can paste the following command to check how to work load balancing.

curl http://<your_ip_address>:87

• You can se which backend instance generated the response

This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_1
This Request redirect to the server backend_2
This Request redirect to the server backend_3
This Request redirect to the server backend_1
...

Author

Kenyeres Géza https://hu.linkedin.com/in/g%C3%A9za-kenyeres-17341631