This project implements TCP Load Balancer with keepalived and nginx. The setup is as follows:

graph LR
  user -->|ports 80 & 443| vip;
  ng1 --- t1;
  ng1 --- t2;
  ng1 --- t3;
  
  subgraph " "
    subgraph load-balancer-1
      vip((vip)) -.- ng1(nginx)
      kl1(keepalived) --- |"health check: localhost:8080/nginx-status"| ng1 
    end
    subgraph load-balancer-2
      kl2(keepalived) --- ng2(nginx)
    end
  end
  subgraph " "
    subgraph Upstream
      t1(Target-1)  
      t2(Target-2)  
      t3(Target-3)  
    end
  end

There can be any number of load balancer and upstream servers. Both keepalived and nginx are un in containers with docker-compose.

Clone this repo to each load balancer server and modify configuration as desribed below.

1. At least two servers with:
   • docker
   • docker-compose
   • ports 80 and 443 open
2. VIP address

1. Copy env-template to .env and edit parameter values in the new .env file if needed.
2. Make sure check-status.sh is executable: chmod +x check-status.sh

Edit target server addresses to following blocks in nginx.conf:

• upsteam_443
• upstream_80

docker-compose up -d

docker-compose down