Tutorial: Load Balancing with Caddy

Overview:

• Purpose:
  • Learn how to use Caddy as a web load balancer.
• Environment:
  • lb01 (load balancer)
  • web01 (web server)
  • web02 (web server)
• Tools:
  • Caddy for load balancing and web serving.
  • Vagrant for VM creation. (Optional)

Cloning the Tutorial Repository:

• Command to Clone the Repository:

  git clone https://github.com/jasonc/caddy-load-balancing-tutorial.git
  

• Change into the Project Directory:

  cd caddy-load-balancing-tutorial
  

Vagrant:

• Vagrantfiles:

  • Vagrantfile:
    • Automates the installation and configuration of the virtual machines, web servers, and load balancer.
  • Vagrantfile.vms:

    • Creates the virtual machines, but does not install Caddy or perform any configuration.

    • To use, replace Vagrantfile with Vagrantfile.vms:

      cp Vagrantfile.vms Vagrantfile
      

• Virtual Machine Creation:

  vagrant up
  

Caddy Configuration Files:

• Caddyfile.random
  • Default random load balancing policy.
• Caddyfile.ip_hash
  • For IP hash load balancing policy.
• Caddyfile.rr
  • For round-robin load balancing policy.

Automated Installation Script (install.sh):

• Adds the Caddy stable repository.
• Installs Caddy on all nodes.
• Configures lb01 with the random load balacing policy by using the Caddyfile.random configuration file.
• Sets up web server hostname in index.html on web01 and web02.

Manual Setup Steps (if not using install.sh):

• Install and Configure Caddy Manually:
  • Follow the tutorial video here.
  • Or duplicate the steps in the install.sh script for each server

Load Balancing Configurations:

• Switching Load Balancer Configurations:

  • Copy the desired Caddyfile to /etc/caddy/Caddyfile on lb01:

    cp Caddyfile.rr /etc/caddy/Caddyfile
    # or
    cp Caddyfile.ip_hash /etc/caddy/Caddyfile
    # or
    cp Caddyfile.random /etc/caddy/Caddyfile
    

  • Reload Caddy:

    sudo systemctl reload caddy
    

Testing Load Balancer:

• From the command line, use curl to test different load balancing policies:

  curl localhost
  

  Or

  curl 192.168.56.50   # the public facing IP of lb01
  

Additional Resources:

• LinuxTrainingAcademy.com Video Lesson
• Caddy installation documentation.
• Caddy reverse proxy documentation, including load balancing policies.