How to Install Magento 1 on CentOS 6

(Added later.) This post is for Magento 1 on CentOS 6. Magento 1 reached end of life on 30 June 2020 and CentOS 6 on 30 November 2020; neither receives security updates. These steps do not apply to Magento 2 / Adobe Commerce.

Here is my simple way to install Magento on CentOS 6.

Before you start

(Added later.)

Run the commands as root or with sudo.
You need a working Apache (httpd), PHP and MySQL setup on the server, and a MySQL database and user for Magento. The original post does not cover these.
Check the system requirements for the exact Magento 1 version you are installing, especially the supported PHP version.

Steps

Download Magento with wget.

Added note: the original just said “wget magento” without a download address, and the original link is not known. The general pattern is to download the archive into your web directory and unpack it:
Terminal window
```
cd /var/www/html
wget <URL of the Magento 1 archive>
tar -xzf <archive name>.tar.gz
```
Replace the placeholders with the real address and file name of the Magento 1 release you are installing. Because Magento 1 is end of life, I am not giving a download link here.
Edit /etc/httpd/conf/httpd.conf.
Terminal window
```
vi /etc/httpd/conf/httpd.conf
```
Added note: the original does not say what to change. Magento 1 relies on its .htaccess file for URL rewrites and security rules, so the usual change is to allow overrides for the Magento directory, for example:
```
<Directory "/var/www/html">
    AllowOverride All
</Directory>
```
Use the directory where you unpacked Magento. Then check the configuration and restart Apache:
Terminal window
```
httpd -t
service httpd restart
```
Install the extra packages and PHP extensions you might need.

Magento 1 needs the PHP mcrypt extension, which is not in the standard CentOS 6 repositories. I installed these packages from the EPEL repository:
1. PHP extension mcrypt: epel.mirror.freedomvoice.com/6/i386/php-mcrypt-5.3.3-1.el6.i686.rpm
2. libmcrypt-devel: http://epel.mirror.freedomvoice.com/6/i386/libmcrypt-devel-2.5.8-9.el6.i686.rpm
3. libmcrypt: http://epel.mirror.freedomvoice.com/6/i386/libmcrypt-2.5.8-9.el6.i686.rpm
Added notes:
- These links point to a third-party EPEL mirror and are for 32-bit (i386/i686) systems only. On a 64-bit server you need the x86_64 packages. The links may no longer work.
- A cleaner way is to enable the EPEL repository and let yum fetch the right packages and their dependencies for your architecture:
  Terminal window
```
yum install php-mcrypt
```
  libmcrypt is installed automatically as a dependency. libmcrypt-devel is only needed if you are compiling software against libmcrypt.
- Restart Apache afterwards so PHP loads the new extension, then check it is loaded:
  Terminal window
```
service httpd restart
php -m | grep mcrypt
```
(Added later.) Run the Magento installer. Open your site in a browser; Magento 1 shows a web-based installation wizard that asks for the database details and creates the admin account.

Notes for today

Do not use this on a live shop. Magento 1 and CentOS 6 are both end of life. For a new shop, use Magento 2 (Magento Open Source / Adobe Commerce) on a supported system and follow its own installation documentation.
CentOS replacements: Rocky Linux and AlmaLinux are the common free replacements; Debian and Ubuntu are alternatives.
Commands on newer systems: service httpd restart became systemctl restart httpd, and yum became dnf (yum still works as an alias).
mcrypt: the mcrypt extension was removed from PHP’s core in PHP 7.2 because the underlying library is no longer maintained. Newer software uses OpenSSL or Sodium instead.
EPEL for CentOS 6 has been moved to the Fedora archive, so normal mirrors no longer carry these packages.