Running sites on different versions of PHP on the same server

This quick guide explains the steps needed to be able to run different versions of PHP on the same server (different virtual hosts or even different folders within the same site).

Prepare

If the ‘add-apt-repository’ command is missing, you need to install the package “software-properties-common” first:

apt install -y software-properties-common

Add the ondrej/php repository to your system:

add-apt-repository ppa:ondrej/php

apt update, upgrade:

apt update
apt upgrade

Install Apache fastCGI module:

apt install -y libapache2-mod-fcgid

For each version of PHP

As of 1 Jan 2021, PHP versions 7.4 (php7.4) and 8.0 (php8.0) are those with active support and updates. PHP version 7.3 (php7.3) will continue to receive critical updates until 1 Jan 2022. See Supported PHP Versions.

Install required packages

apt install -y php7.4 php7.4-fpm php7.4-mysql libapache2-mod-php7.4

Install other wanted modules for the same PHP version, for example these commonly used:

apt install -y php7.4-curl php7.4-gd php7.4-imagick php7.4-intl php7.4-mbstring php7.4-readline php7.4-json

Start the php-fpm service:

systemctl start php7.4-fpm

Check that the service is running:

systemctl status php7.4-fpm

For each version, also any custom configuration in php.ini has to be duplicated. In Ubuntu the php.ini files are located in the subfolders of /etc/php/x.x/ (one subfolder for each run environment, “apache2”, “cgi”, “cli”, “fpm”).

Set new default PHP version used by Apache

To set the default PHP version to use when not overridden by SetHandler below, use the commands a2dismod and a2enmod.
Set default to PHP 8.0

a2dismod php7.4
a2enmod php8.0
systemctl restart apache2

Set default to PHP 7.4

a2dismod php8.0
a2enmod php7.4
systemctl restart apache2

Configuring PHP version for virtual host or subfolder

Activate necessary Apache modules and restart Apache:

a2enmod actions fcgid alias proxy_fcgi
systemctl restart apache2

Use FilesMatch directive to set the PHP version:
FilesMatch is valid in both the virtualhost configuration and inside a Directory section.
To set PHP version globally for a virtual host, use it outside a Directory section.
The default PHP version can be set using ‘a2enmod php8.0’ (or any other version)

<FilesMatch \.php$>
  SetHandler "proxy:unix:/run/php/php7.4-fpm.sock|fcgi://localhost"
</FilesMatch>

Check the configuration for errors:

apachectl configtest

If result is “Syntax OK”, restart Apache:

systemctl restart apache2

Overriding PHP version using .htaccess

For this to work, “AllowOverride FileInfo” must be present for the directory (or above) in which the .htaccess file will be used to set the PHP version.
For the default virtual host, the DocumentRoot is set to /var/www/html, so to allow PHP version to be set by .htaccess at that level or below, the following must be present in the vhost configuration:

  <Directory /var/www/html>
    AllowOverride FileInfo
  </Directory>

When this has been set, FilesMatch and SetHandler (as described above) can be used within the .htaccess file. The .htaccess method have higher priority than what is set for the virtualhost, or the subfolder within the DocumentRoot of the virtual host.

Testing

Create a file named ‘i.php’ in the locations with the different PHP versions (can be different virtualhosts or folders)

<?php
phpversion();
?>

Access these locations on the virtualhosts or their directory locations to verify that they are using different PHP versions.

References

Most useful resource for this guide
How To Run Multiple PHP Versions on One Server Using Apache and PHP-FPM on Ubuntu 18.04 (DigitalOcean Community)

Javascript

https://stackoverflow.com/questions/43958335/select-folder-instead-of-single-file-input
https://stackoverflow.com/questions/14425007/get-metadata-of-local-mp3-file-using-html5-filesystem-api
https://stackoverflow.com/questions/3544898/what-does-a-colon-mean-within-an-html-id-attribute
https://stackoverflow.com/questions/441018/replacing-spaces-with-underscores-in-javascript
https://stackoverflow.com/questions/42526032/how-to-find-if-element-with-specific-id-exists-or-not/42526074
https://stackoverflow.com/questions/4250364/how-to-trim-a-file-extension-from-a-string-in-javascript
https://stackoverflow.com/questions/19331606/onclick-add-image-to-div
https://www.google.se/search?q=select+local+file+play+with+html5&oq=select+local+file+play+with+html5
Detect if HTML5 video is playing or paused and show or hide a Div accordingly
https://stackoverflow.com/questions/31307146/javascript-button-stop-all-audio-on-page
https://stackoverflow.com/questions/3623110/get-an-elements-id
https://www.google.com/search?q=javascript+store+data+inside+a+div&ie=utf-8&oe=utf-8&client=firefox-b
https://stackoverflow.com/questions/5785833/how-to-change-link-hrefs-via-javascript
Using files from web applications

HTML & CSS

Responsive IFRAMEs — The Right Way (CSS Only)!
How to Auto-resize an Image to Fit into a DIV Container using CSS

Everything You Need to Know About HTML’s ‘pre’ Element

CSS selector last row from main table
https://stackoverflow.com/questions/16010791/css-selector-last-row-from-main-table

Google search – “html5 canvas layers transparency”
https://www.google.se/search?q=html5+canvas+layers+transparency

Tutorial: How To Style the HTML 5 Audio Player
https://serversideup.net/style-the-html-5-audio-element/

Play local video file with HTML5
https://jsfiddle.net/dsbonev/cCCZ2/

Use Fetch as Google for websites
https://support.google.com/webmasters/answer/6066468?hl=en

hreview-examples
http://microformats.org/wiki/hreview-examples

PDF from every page of website
https://mpdf.github.io/real-life-examples/pdf-from-every-page-of-website.html

Google: php add protection to existing pdf
https://www.google.se/search?q=php+add+protection+to+existing+pdf

Custom colored Bootstrap button
https://codepen.io/anon/pen/RdBqbY
http://blog.koalite.com/bbg/

Styling checkboxes
https://stackoverflow.com/questions/49355676/trying-to-change-color-of-custom-checkbox-label-when-checked-css-only

Text
Background
Border (darken background 10%)
Active (darken background 7.5%)

SSL certificate / VPN

SSL

Let’s Encrypt
https://letsencrypt.org/docs/
https://letsencrypt.org/getting-started/
https://weblog.west-wind.com/posts/2016/Feb/22/Using-Lets-Encrypt-with-IIS-on-Windows
How To Secure Apache with Let’s Encrypt on Ubuntu 20.04
Configuring Let’s Encrypt SSL Cert for Apache on Ubuntu 18.04
Let’s Debug

SSL for free
https://www.sslforfree.com/

RapidSSL
https://www.rapidssl.com/

Certbot
https://certbot.eff.org/

https on subdomain
https://se.godaddy.com/community/Managing-Domains/https-on-subdomain/td-p/30668

SSL Server Test
How to disable outdated versions of SSL/TLS in Apache

VPN

https://support.ivacy.com/kb/how-to-configure-pptp-on-your-linksys-router/