The Apache HTTP Server, colloquially called Apache, is the world's most widely used web server software. Originally based on the NCSA HTTPd server, development of Apache began in early 1995 after work on the NCSA code stalled. Apache played a key role in the initial growth of the World Wide Web, quickly overtaking NCSA HTTPd as the dominant HTTP server, and has remained the most popular HTTP server since April 1996. In 2009, it became the first web server software to serve more than 100 million websites.1

References

• Documentation: Apache HTTP Server

Installation

• How to install Apache, PHP 7.2 and MySQL on CentOS 7.4 (LAMP)
• Install Apache2, MariaDB, and PHP 7.1 (LAMP) on Ubuntu 16.04 LTS Server
• Ubuntu 18.04 (LTS) LAMP server tutorial with Apache, PHP 7.2, and MySQL

Virtual Host

The term Virtual Host refers to the practice of running more than one web site (such as company1.example.com and company2.example.com) on a single machine. Virtual hosts can be "IP-based", meaning that you have a different IP address for every web site, or "name-based", meaning that you have multiple names running on each IP address. The fact that they are running on the same physical server is not apparent to the end user.2

<VirtualHost *:80>
    ServerAdmin webmaster@dummy-host.example.com
    DocumentRoot "\var\www\mydomain"
    ServerName mydomain.dev
    ServerAlias www.mydomain.dev
    ErrorLog "logs/dummy-host.mydomain.dev-error.log"
    CustomLog "logs/dummy-host.mydomain.dev-access.log" common
</VirtualHost>

<VirtualHost *:80>
    ServerAdmin webmaster@dummy-host.example.com
    DocumentRoot "/var/www/mydomain"
    ServerName mydomain.dev
    ServerAlias www.mydomain.dev
    <Directory /var/www/mydomain>
       Options Indexes FollowSymLinks MultiViews
       AllowOverride All
       Require all granted
    </Directory>
    ErrorLog "logs/dummy-host.mydomain.dev-error.log"
    CustomLog "logs/dummy-host.mydomain.dev-access.log" common
</VirtualHost>

Upgrade Apache 2.2 to Apache 2.4

• https://httpd.apache.org/docs/2.4/upgrading.htmlUpgrading to 2.4 from 2.2
• Updating Virtual Host Settings from Apache 2.2 to Apache 2.4
• How To Migrate your Apache Configuration from 2.2 to 2.4 Syntax.

Configure Apache to use the Signed SSL/TLS Certificates

The Apache HTTP Server module mod_ssl provides an interface to the OpenSSL library, which provides Strong Encryption using the Secure Sockets Layer and Transport Layer Security protocols.3

• Apache SSL/TLS Encryption
• SSL/TLS Strong Encryption: An Introduction

<VirtualHost 12.34.56.78:443>
     SSLEngine On
     SSLCertificateFile /etc/apache2/ssl/www.mydomain.com.crt
     SSLCertificateKeyFile /etc/apache2/ssl/www.mydomain.com.key
     SSLCACertificateFile /etc/apache2/ssl/verisign.cer

     ServerAdmin info@mydomain.com
     ServerName www.mydomain.com
     DocumentRoot /srv/www/mydomain.com/public_html/
     ErrorLog /srv/www/mydomain.com/logs/error.log
     CustomLog /srv/www/mydomain.com/logs/access.log combined
</VirtualHost>