LBX: Loadbalancer in GO

We Balance Loads, and Occasionally Your Sanity

This project implements a simple load balancer in Go that distributes incoming requests across multiple backend servers using a Round Robin algorithm. The load balancer reads configuration from a YAML file and forwards requests to the backend servers in a rotating manner.

Example Configuration

The load balancer configuration is specified in a YAML file (config.yml). Below is an example configuration:

entry_point: 3000
servers:
  - name: server1
    url: http://server1:3000
  - name: server2
    url: http://server2:3000
  - name: server3
    url: http://server3:3000

• entry_point: The port where the load balancer will listen for incoming traffic.
• servers: A list of backend servers where the load balancer will forward requests.
  • name: The name of the server.
  • url: The URL of the backend server that will handle the requests.

Build and Run the Load Balancer

1. Docker Setup

You can run the load balancer as a Docker container by using the following command:

docker run --name lbx -v config.yml:/app/config.yml -p 3000:3000 subrotokumar/lbx

Parameters:

• --name lbx: Assigns the name lbx to the container.
• -v config.yml:/app/config.yml: Mounts the local config.yml file into the container.
• -p 3000:3000: Exposes port 3000 on your local machine and maps it to port 3000 in the container.
• subrotokumar/lbx: The Docker image for the load balancer.

Once the container is running, the load balancer will start listening on port 3000. Requests to this port will be distributed across the backend servers defined in the configuration file using the round-robin algorithm.

Load Balancer Logic

The load balancer will:

1. Receive incoming requests on the configured entry point (e.g., port 3000).
2. Distribute these requests to the backend servers in a round-robin fashion:
   • After sending a request to server1, the next request will go to server2, then server3, and so on.
   • Once all servers have received a request, the cycle repeats starting from server1.

Example Use Case

1. You have three backend servers: server1, server2, and server3, each running on port 3000.
2. The load balancer receives incoming HTTP requests on port 3000 and forwards them to each of these servers in a round-robin order.
3. If server1 handles a request, the next request will go to server2, and the next to server3. After that, it starts over at server1.

Docker Compose Example (Optional)

You can also run the load balancer and the backend servers using Docker Compose. Here's an example docker-compose.yml file:

version: "3.7"

services:
  lbx:
    image: subrotokumar/lbx
    ports:
      - "3000:3000"
    volumes:
      - ./config.yml:/app/config.yml
    depends_on:
      - server1
      - server2
      - server3

  server1:
    image: some-http-server-image
    environment:
      - SERVER_NAME=server1
    expose:
      - "3000"

  server2:
    image: some-http-server-image
    environment:
      - SERVER_NAME=server2
    expose:
      - "3000"

  server3:
    image: some-http-server-image
    environment:
      - SERVER_NAME=server3
    expose:
      - "3000"

To start the services, run:

docker-compose up

This will start the load balancer and the three backend servers, with the load balancer forwarding traffic to them in round-robin order.

License

This project is open-source and available under the MIT License.

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This README provides an overview of how to configure and run the load balancer, including Docker setup instructions, configuration examples, and the load balancing logic.