Installing WHMCS

Download WHMCS

Download WHMCS from their Official Website
Install unzip with apt install unzip
Extract the zip with cd /var/www && unzip whmcs_*

Install Apache

apt install apache2

Generating SSL/TLS Certificates

Downloading Certbot

To begin, we will install certbot, a simple script that automatically renews our certificates and allows much easier creation of them. The command below is for Ubuntu distributions, but you can always check Certbot’s Official Website for installation instructions. We have also included a command below to install certbot’s Apache plugin so you won’t have to stop your webserver.

apt update
apt install -y certbot python3-certbot-apache

Completing the HTTP Challenge

Make sure you have port 80 open on your firewall
Request a certificate from Let’s Encrypt, you should replace billing.example.com with the domain you would like to generate a certificate for.

certbot certonly --apache -d billing.example.com

Automatically Renewing SSL/TLS certificates

Install crontab:

apt install cron

Create a crontab rule for the automatic renewal:

(crontab -l ; echo "0 23 * * * certbot renew --quiet --deploy-hook \"systemctl restart apache2\"")| crontab -

Webserver Configuration

Remove the default configuration:

a2dissite 000-default.conf

Create a new Apache site configuration like whmcs.conf in /etc/apache2/sites-available using a text editor like nano or vim.
Paste the text below into the file, replacing billing.example.com with your domain:

whmcs.conf

<VirtualHost *:80>
    ServerName billing.example.com
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/whmcs
    Options -Indexes
 
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
 
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</VirtualHost>
 
<VirtualHost *:443>
    <Directory /var/www/>
        Options -Indexes
        AllowOverride All
        Require all granted
        Order allow,deny
        allow from all
    </Directory>
    ServerName billing.example.com
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/whmcs
 
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
 
    # PHP Limits
    php_value upload_max_filesize 100M
    php_value post_max_size 100M
 
    # SSL Configuration
    SSLEngine on
    SSLCertificateFile /etc/letsencrypt/live/billing.example.com/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/billing.example.com/privkey.pem
 
    # Headers
    Header always set X-Content-Type-Options "nosniff"
    Header always set X-XSS-Protection "1; mode=block"
    Header always set X-Robots-Tag "none"
    Header always set Content-Security-Policy "frame-ancestors 'self'"
    Header always set X-Frame-Options "DENY"
    Header always set Referrer-Policy "same-origin"
    Header always set Permissions-Policy "accelerometer=(), camera=(), fullscreen=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), usb=()"
</VirtualHost>

Link Config

Enable your new Apache website configuration and required modules:

ln -s /etc/apache2/sites-available/whmcs.conf /etc/apache2/sites-enabled/whmcs.conf

Install PHP

apt-add-repository universe
apt -y install libapache2-mod-php8.1 php8.1 php8.1-{common,cli,gd,mysql,mbstring,bcmath,xml,fpm,curl,zip,bcmath,gmp,intl,mbstring,soap}

Install IonCube

wget https://downloads.ioncube.com/loader_downloads/ioncube_loaders_lin_x86-64.tar.gz
tar -xzvf ioncube_loaders_lin_x86-64.tar.gz
 
cp ioncube/ioncube_loader_lin_8.1.so /usr/lib/php/20210902/

Add IonCube Extension to CLI PHP.ini:

/etc/php/8.1/cli/php.ini

zend_extension = "/usr/lib/php/20210902/ioncube_loader_lin_8.1.so"

Add IonCube Extension to Apache PHP.ini:

/etc/php/8.1/apache2/php.ini

zend_extension = "/usr/lib/php/20210902/ioncube_loader_lin_8.1.so"

Check if IonCube was successfully installed:

php -v

Enable Required Modules

a2enmod rewrite
a2enmod headers
a2enmod ssl
# List Modules
apachectl -M

Restart Apache and PHP

systemctl restart apache2
systemctl restart php8.1-fpm

Install MariaDB

curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash
apt install mariadb-server

Enter MySQL Shell

mysql

Create Database

CREATE DATABASE whmcs;
CREATE USER 'whmcsuser'@'127.0.0.1' IDENTIFIED BY 'somePasswordHere';
GRANT ALL PRIVILEGES ON whmcs.* TO 'whmcsuser'@'127.0.0.1';

Strict Privileges

If you wish to have strict database privileges instead, only allow the following:

When installing WHMCS, updating WHMCS, activating modules, or deactivating modules, the following privileges are required:

ALTER
CREATE
DROP
INDEX

For day-to-day use, only the following database privileges are required:

DELETE
INSERT
SELECT
UPDATE
LOCK TABLES

Setting File Permissions

chown -R www-data:www-data /var/www/whmcs

Create Cron Schedule

(crontab -l ; echo "*/5 * * * * /usr/bin/php -q /var/www/crons/cron.php")| crontab -

Begin Setup

Visit your domain and click “Click here to begin…”
Read and either agree or disagree with the WHMCS EULA
Fix any errors, most commonly are simple file permission errors
Input your database login credentials
Input your license and create an administrator user

Setup Bungeecord Identity Providers