How To Install HAProxy on Ubuntu 20.04 LTS

In this tutorial, we will show you how to install HAProxy on Ubuntu 20.04 LTS. For those of you who didn’t know, HAProxy is a free HTTP/TCP high availability load balancer and proxy server. It spreads requests among multiple servers to mitigate issues resulting from a single server failure. HA Proxy is used by a number of high-profile websites including GitHub, Bitbucket, Stack Overflow, Reddit, Tumblr, Twitter, and Tuenti, and is used in the OpsWorks product from Amazon Web Services.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of HAProxy on Ubuntu 20.04 (Focal Fossa). You can follow the same instructions for Ubuntu 18.04, 16.04, and any other Debian-based distribution like Linux Mint.

Prerequisites

• A server running one of the following operating systems: Ubuntu 20.04, 18.04, 16.04, and any other Debian-based distribution like Linux Mint.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install HAProxy on Ubuntu 20.04 LTS Focal Fossa

Step 1. First, make sure that all your system packages are up-to-date by running the following apt commands in the terminal.

sudo apt update
sudo apt upgrade
sudo apt install software-properties-common

Step 2. Network Details.

To install and configure HAProxy load balancer on Ubuntu 20.04 system, we will consider three systems as follows:

Web Server Details: 
Server 1: web1.idroot.us   192.168.77.20
Server 2: web2.idroot.us   192.168.77.21

HAProxy Server: 
HAProxy: haproxy           192.168.77.46

Step 3. Installing HAProxy on Ubuntu 20.04.

Now we add the HAProxy PPA repository for Ubuntu:

sudo curl https://haproxy.debian.net/bernat.debian.org.gpg | apt-key add -
sudo echo "deb http://haproxy.debian.net $(lsb_release -cs)-backports-2.0 main" | tee /etc/apt/sources.list.d/haproxy.list
sudo add-apt-repository ppa:vbernat/haproxy-2.1

Once done, you can install HAProxy using the following command:

sudo apt update
sudo apt install haproxy

Step 4. Configure HAProxy.

The main configuration file for HAProxy is /etc/haproxy/haproxy.cfg Now we edit and start the configuration:

sudo nano /etc/haproxy/haproxy.cfg

Add the following file:

# add to the end
# define frontend ( any name is OK for [http-in] )
frontend http-in
        # listen 80 port
        bind *:80
        # set default backend
        default_backend    backend_servers
        # send X-Forwarded-For header
        option             forwardfor

# define backend
backend backend_servers
        # balance with roundrobin
        balance            roundrobin
        # define backend servers
        server             node01 192.168.77.21:80 check
        server             node02 192.168.77.46:80 check

Once done, you can restart it by running the command below:

sudo systemctl restart haproxy

Next, change settings on the Backend Web server to log the X-Forwarded-For header. The follows are for the case of Apache2 settings:

a2enmod remoteip
sudo nano /etc/apache2/apache2.conf

Add the following file:

# line 212-215 : change like follows
# for RemoteIPInternalProxym, specify HAProxy IP address
RemoteIPHeader X-Forwarded-For
RemoteIPInternalProxy 192.168.77.20
LogFormat "%v:%p %a %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
LogFormat "%a %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined

Save and close the file, also restart the Apache service:

sudo systemctl restart apache2

Step 5. Accessing HAProxy.

With the HAProxy configured and running, open your load balancer server’s public IP in a web browser and check that you get connected to your backend correctly. The parameter stats URI in the configuration enables the statistics page at the defined address:

http://192.168.77.46

Congratulations! You have successfully installed HAProxy. Thanks for using this tutorial for installing the HAProxy on your Ubuntu 20.04 LTS Focal Fossa system. For additional help or useful information, we recommend you to check the official HAProxy website.