This post explains how to install or upgrade to PHP 7.2 on Ubuntu. It is assumed PHP 5.x is running on an Ubuntu 14.04 machine in case of upgrade.

Note: This new version brings with it a number of new features and a few incompatibilities that should be tested for before switching PHP versions in production environments.

Read Also: Installing Linux, Apache, MySQL, PHP (LAMP) Stack on Ubuntu 14.04

Steps:

1. Add a PPA for PHP 7.2 Packages

sudo add-apt-repository ppa:ondrej/php

2. update the local package cache

sudo apt-get update
sudo apt-get upgrade

Apache

3. For Apache, install the new packages: (To configuring PHP-FPM With Nginx, go to step 6)

sudo apt-get install php7.2

If you are using MySQL, make sure to re-add the updated PHP MySQL bindings:

sudo apt-get install php7.2-mysql

If you want to install all common packages, you can run following command

sudo apt-get install php7.2-cli php7.2-common libapache2-mod-php7.2 php7.2 php7.2-mysql php7.2-fpm

You might need to install mbstring package also:

sudo apt-get install php7.2-mbstring

4. To update web-server configuration:

Apache with php-fpm:

a2disconf php5-fpm
a2enconf php7.2

Apache with mod_php:

sudo a2dismod php5
sudo a2enmod php7.2

5. Restart Apache

sudo service apache2 restart

Nginx

6. If you are using Nginx as the web server and PHP-FPM to execute PHP code, install the new PHP-FPM package and its dependencies:

sudo apt-get install php7.2-fpm

If you are using MySQL, make sure to re-add the updated PHP MySQL bindings:

sudo apt-get install php7.2-mysql

7. Now you need to update fastcgi_pass configuration to point new version file. Open the default site configuration file

sudo nano /etc/nginx/sites-enabled/default

In the file, go to Server > location ~ \.php$ > fastcgi_pass. Probably it would look like below:

fastcgi_pass unix:/var/run/php/php5-fpm.sock;

change the above with new version:

fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;

Similarly, you can do the same with your any other virtual sites defined in /etc/nginx/sites-enabled.

8. Restart Nginx

sudo service nginx restart

9. Before upgrading, if you want to do it from scratch means want to uninstall the existing nginx and install a fresh version.

To uninstall:

sudo apt-get purge nginx nginx-common nginx-full

To install:

sudo apt-get update
sudo apt-get install nginx

Clean up

Run phpinfo(), php --info or php -v to verify PHP 7.2 setup.

If all is well, you can clean up old versions:

sudo apt purge php5*  

Now you have working PHP 7.2 environment.

Enjoy PHP !!