To install HAProxy on Rocky Linux, you can follow the same steps as for installing it on Rocky Linux. Here is a summary of the steps:

• Add the PostgreSQL yum repository to your system:

sudo yum install -y <https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm>

• Install the haproxy package:

sudo yum install -y haproxy

• Enable and start the haproxy service:

sudo systemctl enable haproxy
sudo systemctl start haproxy

• Edit the HAProxy configuration file at /etc/haproxy/haproxy.cfg and add the necessary configuration for your setup.
• Restart HAProxy:

sudo systemctl restart haproxy

After following these steps, HAProxy should be installed and running on your Rocky Linux server. You can verify this by checking the logs:

tail -f /var/log/haproxy.log

You can then use HAProxy as described in the previous article, for example, for load balancing and reverse proxying.

Here are some examples of how you can use HAProxy:

• Load balancing HTTP traffic: You can use HAProxy to balance incoming HTTP traffic between multiple backend servers. This can improve the performance and reliability of your web applications.
• Load balancing TCP traffic: HAProxy can also balance TCP traffic, such as HTTPS or SSH, between multiple backend servers. This allows you to distribute the load and avoid overloading any single server.
• Reverse proxying: In addition to load balancing, HAProxy can also act as a reverse proxy, forwarding requests from the internet to your backend servers. This can improve security by hiding the internal IP addresses of your servers from external clients.
• SSL termination: HAProxy can terminate SSL connections and forward the unencrypted requests to the backend servers. This reduces the load on the backend servers and allows you to use a single SSL certificate for multiple domains.

These are just a few examples of how you can use HAProxy. There are many more features and capabilities available in HAProxy, and you can explore them as you use the tool.

And example of a HAProxy configuration that balances HTTP traffic between two backend servers:

frontend main
    bind *:80
    default_backend app

backend app
    balance roundrobin
    server app1 10.0.0.1:8080 check
    server app2 10.0.0.2:8080 check

This configuration tells HAProxy to listen on port 80 and forward the incoming requests to the app backend, which consists of two servers at the specified IP addresses and ports. The roundrobin algorithm is used to distribute the requests evenly between the servers. The check option enables health checks for the servers, ensuring that only healthy servers receive traffic.

Here is another example of a HAProxy configuration that acts as a reverse proxy for HTTPS traffic:

frontend https
    bind *:443 ssl crt /etc/haproxy/ssl/cert.pem
    default_backend app

backend app
    balance roundrobin
    server app1 10.0.0.1:8443 check ssl
    server app2 10.0.0.2:8443 check ssl

This configuration tells HAProxy to listen on port 443 and forward the incoming HTTPS requests to the app backend, which consists of two servers at the specified IP addresses and ports. The ssl and crt options enable SSL termination on the HAProxy server and specify the path to the SSL certificate. The check and ssl options enable health checks and SSL encryption for the backend servers.

These are just two examples of HAProxy configurations. You can customize and combine the options to create a configuration that fits your specific needs.

In conclusion, HAProxy is a versatile and powerful tool for improving the performance and reliability of your applications. By following the steps outlined in this article, you can easily install and configure HAProxy on Rocky Linux and use it in various scenarios. The examples and configurations provided in this article can serve as a starting point for creating your own HAProxy setup. With its many features and capabilities, HAProxy can help you deliver high-quality and scalable services to your users.