/mini-load-balancer

Primary LanguageGo

Mini Load Balancer Using Docker

Objectives

  • Write more Golang
  • Learn Docker - images, containers, docker compose, docker networks
  • Learn Load Balancing & Implement Service Discovery + Round Robin load balancing

Build It!

Docker Images

$ docker image build -t mlb-server:latest server
$ docker image build -t mlb-balancer:latest .

The current directory contains the source files for the balancer itself

The server directory holds the source files for the servers we're load balancing on

Docker Compose

Important

In case you're trying to run this on Windows or MacOS, you're going to have to execute the following command

$ docker compose -f docker-compose.dev.yaml -d

This will start up a Docker in Docker container where you'll be provided with a docker0 network interface enabling the load balancer to actually reach the containers deployed

Start up a shell prompt within the parent container on your host

$ docker exec -it parent /bin/sh

Following which you'll deploy the configuration within docker-compose.yaml

  • Deploy docker-compose.yaml
$ docker compose up
  • Inspect the network created (src_shared) using docker inspect
  • Make a note of the IP address generated for the container running the image mlb-balancer
  • Send requests to the generated IP and observe the responses sent back from different containers!

Note

Try stopping and restarting containers and observe the effects request routing has on the resulting deployment
You will notice the load balancer picking up on changes within the docker network