Apache

• How to Install LAMP Stack on Ubuntu 20.04 Server
• How to Install LAMP Stack on CentOS 8/RHEL 8
• How to Install LAMP Stack on Debian 10 Buster Server

How to Install LAMP Stack on Ubuntu 20.04 Server

This tutorial is going to show you how to install LAMP stack on Ubuntu 20.04 LTS. A software stack is a set of software tools bundled together. LAMP stands for Linux, Apache, MariaDB/MySQL and PHP, all of which are open source and free to use. It is the most common software stack that powers dynamic websites and web applications. Linux is the operating system; Apache is the web server; MariaDB/MySQL is the database server and PHP is the server-side scripting language responsible for generating dynamic web pages.

Prerequisites

To follow this tutorial, you need an Ubuntu 20.04 OS running on your local computer or on a remote server.

If you are looking for a VPS (Virtual Private Server), then you can register an account at DigitalOcean via this special link to get $50 free credit. (For new users only). If you are already a DigitalOcean user, then you can register an account on Vultr via this special link to get $50 free credit (for new users only).

And if you need to set up LAMP stack with a domain name, I recommend buying domain names from NameCheap because the price is low and they give whois privacy protection free for life.

Step 1: Update Software Packages

Before we install the LAMP stack, it’s a good idea to update repository and software packages. Run the following commands on your Ubuntu 20.04 OS.

sudo apt update

sudo apt upgrade

Step 2: Install Apache Web Server

Enter the following command to install Apache Web server. The apache2-utils package will install some useful utilities like Apache HTTP server benchmarking tool (ab).

sudo apt install -y apache2 apache2-utils

After it’s installed, Apache should be automatically started. Check its status with systemctl.

systemctl status apache2

Sample output:

● apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2020-04-11 11:31:31 CST; 2s ago
       Docs: https://httpd.apache.org/docs/2.4/
    Process: 53003 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
   Main PID: 53011 (apache2)
      Tasks: 55 (limit: 19072)
     Memory: 6.4M
     CGroup: /system.slice/apache2.service
             ├─53011 /usr/sbin/apache2 -k start
             ├─53012 /usr/sbin/apache2 -k start
             └─53013 /usr/sbin/apache2 -k start

Hint: If the above command doesn’t quit immediately, you can press Q key to gain back control of the terminal.

If it’s not running, use systemctl to start it.

sudo systemctl start apache2

It’s also a good idea to enable Apache to automatically start at system boot time.

sudo systemctl enable apache2

Check Apache version:

apache2 -v

Output:

Server version: Apache/2.4.41 (Ubuntu)
Server built:   2020-03-05T18:51:00

Now type in the public IP address of your Ubuntu 20.04 server in the browser address bar. You should see the “It works!” Web page, which means Apache Web server is running properly. If you are installing LAMP on your local Ubuntu 20.04 computer, then type 127.0.0.1 or localhost in the browser address bar.

If the connection is refused or failed to complete, there might be a firewall preventing incoming requests to TCP port 80. If you are using iptables firewall, then you need to run the following command to open TCP port 80.

sudo iptables -I INPUT -p tcp --dport 80 -j ACCEPT

If you are using UFW firewall, then run this command to open TCP port 80.

sudo ufw allow http

Now we need to set www-data (Apache user) as the owner of document root (otherwise known as web root). By default it’s owned by the root user.

sudo chown www-data:www-data /var/www/html/ -R

By default, Apache uses the system hostname as its global ServerName. If the system hostname can’t be resolved in DNS, then you will probably see the following error after running sudo apache2ctl -t command.

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message

To solve this problem, we can set a global ServerName in Apache. Use the Nano command-line text editor to create a new configuration file.

sudo nano /etc/apache2/conf-available/servername.conf

Add the following line in this file.

ServerName localhost

Save and close the file. To save a file in Nano text editor, press Ctrl+O, then press Enter to confirm. To exit, press Ctrl+X. Then enable this config file.

sudo a2enconf servername.conf

Reload Apache for the change to take effect.

sudo systemctl reload apache2

Now if you run the sudo apache2ctl -t command again, you won’t see the above error message.

Step 3: Install MariaDB Database Server

MariaDB is a drop-in replacement for MySQL. It is developed by former members of MySQL team who are concerned that Oracle might turn MySQL into a closed-source product. Enter the following command to install MariaDB on Ubuntu 20.04.

sudo apt install mariadb-server mariadb-client

After it’s installed, MariaDB server should be automatically started. Use systemctl to check its status.

systemctl status mariadb

Output:

● mariadb.service - MariaDB 10.3.22 database server
     Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2020-04-10 14:19:16 UTC; 18s ago
       Docs: man:mysqld(8)
             https://mariadb.com/kb/en/library/systemd/
   Main PID: 9161 (mysqld)
     Status: "Taking your SQL requests now..."
      Tasks: 31 (limit: 9451)
     Memory: 64.7M
     CGroup: /system.slice/mariadb.service
             └─9161 /usr/sbin/mysqld

If it’s not running, start it with this command:

sudo systemctl start mariadb

To enable MariaDB to automatically start at boot time, run

sudo systemctl enable mariadb

Now run the post-installation security script.

sudo mysql_secure_installation

When it asks you to enter MariaDB root password, press Enter key as the root password isn’t set yet. Then enter y to set the root password for MariaDB server.

Next, you can press Enter to answer all remaining questions, which will remove anonymous user, disable remote root login and remove test database. This step is a basic requirement for MariaDB database security. (Notice that Y is capitalized, which means it is the default answer. )

By default, the MariaDB package on Ubuntu uses unix_socket to authenticate user login, which basically means you can use username and password of the OS to log into MariaDB console. So you can run the following command to login without providing MariaDB root password.

sudo mariadb -u root

To exit, run

exit;

Check MariaDB server version information.

mariadb --version

As you can see, we have installed MariaDB 10.3.22.

mariadb  Ver 15.1 Distrib 10.3.22-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

Step 4: Install PHP7.4

At the the time of this writing, PHP7.4 is the latest stable version of PHP and has a minor performance edge over PHP7.3. Enter the following command to install PHP7.4 and some common PHP modules.

sudo apt install php7.4 libapache2-mod-php7.4 php7.4-mysql php-common php7.4-cli php7.4-common php7.4-json php7.4-opcache php7.4-readline

Enable the Apache php7.4 module then restart Apache Web server.

sudo a2enmod php7.4

sudo systemctl restart apache2

Check PHP version information.

php --version

Output:

PHP 7.4.3 (cli) (built: Mar 26 2020 20:24:23) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.3, Copyright (c), by Zend Technologies

To test PHP scripts with Apache server, we need to create a info.php file in the document root directory.

sudo nano /var/www/html/info.php

Paste the following PHP code into the file.

<?php phpinfo(); ?>

To save a file in Nano text editor, press Ctrl+O, then press Enter to confirm. To exit, press Ctrl+X.  Now in the browser address bar, enter server-ip-address/info.php. Replace server-ip-address with your actual IP. If you follow this tutorial on your local computer, then type 127.0.0.1/info.php or localhost/info.php.

You should see your server’s PHP information. This means PHP scripts can run properly with Apache web server.

How to Run PHP-FPM with Apache

There are basically two ways to run PHP code with Apache web server:

• Apache PHP module
• PHP-FPM.

In the above steps, the Apache PHP7.4 module is used to handle PHP code, which is usually fine. But in some cases, you need to run PHP code with PHP-FPM instead. Here’s how.

Disable the Apache PHP7.4 module.

sudo a2dismod php7.4

Install PHP-FPM.

sudo apt install php7.4-fpm

Enable proxy_fcgi and setenvif module.

sudo a2enmod proxy_fcgi setenvif

Enable the /etc/apache2/conf-available/php7.4-fpm.conf configuration file.

sudo a2enconf php7.4-fpm

Restart Apache for the changes to take effect.

sudo systemctl restart apache2

Now if you refresh the info.php page in your browser, you will find that Server API is changed from Apache 2.0 Handler to FPM/FastCGI, which means Apache web server will pass PHP requests to PHP-FPM.

Congrats! You have successfully installed LAMP stack (Apache, MariaDB and PHP7.4) on Ubuntu 20.04. For your server’s security, you should delete info.php file now to prevent prying eyes.

sudo rm /var/www/html/info.php

How to Install LAMP Stack on CentOS 8/RHEL 8

This tutorial is going to show you how to install LAMP stack on CentOS 8 and RHEL 8.

What’s LAMP Stack?

A software stack is a set of software tools bundled together. LAMP stands for Linux, Apache, MariaDB/MySQL and PHP, all of which are open source. It is the most common software stack that powers dynamic websites and web applications. Linux is the operating system; Apache is the web server; MariaDB/MySQL is the database server and PHP is the server-side scripting language responsible for generating dynamic web pages.

Prerequisites

You can download and install RHEL 8 by following the tutorial below.

If you are looking for a VPS (Virtual Private Server), then you can register an account at Vultr via my referral link to get $50 free credit for use over 30 days.

This tutorial uses root account to manage administration tasks. To switch to root, run the following command and enter root password.

su -

Step 1: Update Software Packages

Before we install the LAMP stack, it’s a good idea to run the following command to update repository and software packages.

dnf update

Step 2: Install Apache Web Server on CentOS 8/RHEL 8

Enter the following command to install Apache Web server. The httpd-tools package will install some useful utilities like Apache HTTP server benchmarking tool (ab).

dnf install httpd httpd-tools

After it’s installed, we can start Apache with this command:

systemctl start httpd

Enable Apache to auto start at system boot time by running the following command.

systemctl enable httpd

Now check its status.

systemctl status httpd

Output:

● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2019-10-12 06:43:15 UTC; 14s ago
     Docs: man:httpd.service(8)
 Main PID: 14515 (httpd)
   Status: "Running, listening on: port 80"
    Tasks: 213 (limit: 5092)
   Memory: 24.8M
   CGroup: /system.slice/httpd.service
           ├─14515 /usr/sbin/httpd -DFOREGROUND
           ├─14516 /usr/sbin/httpd -DFOREGROUND
           ├─14517 /usr/sbin/httpd -DFOREGROUND
           ├─14518 /usr/sbin/httpd -DFOREGROUND
           └─14519 /usr/sbin/httpd -DFOREGROUND

“Enabled” indicates that auto start at boot time is enabled and we can see that Apache is running.

Hint: If the above command doesn’t immediately quit after running. You need to press “q” to make it quit.

Check Apache version.

httpd -v

Output:

Server version: Apache/2.4.37 (centos)
Server built: Oct 7 2019 21:42:02

To test if Apache web server is running properly, we can create an index.html file under the default document root (/var/www/html/) with the following command.

echo "Welcome to this site!" > /var/www/html/index.html

If you are installing LAMP on your local CentOS 8/RHEL 8 computer, then type 127.0.0.1 or localhost in the browser address bar. You should see the welcome message, which means Apache Web server is running properly.

By default, CentOS 8/RHEL 8 forbids public access to port 80. To allow other computers to access the web page, we need to open port 80 in firewalld, the dynamic firewall manager on RHEL/CentOS. Run the following command to open port 80.

firewall-cmd --permanent --zone=public --add-service=http

If you want to enable HTTPS on Apache later, then you also need to open port 443.

firewall-cmd --permanent --zone=public --add-service=https

The --permanent option will make this firewall rule persistent across system reboots. Next, reload the firewall daemon for the change to take effect.

systemctl reload firewalld

Now the Apache web page is accessible publicly.

We need to make user apache as the owner of web directory. By default it’s owned by the root user.

chown apache:apache /var/www/html -R

By default, Apache uses the system hostname as its global ServerName. If the system hostname can’t be resolved in DNS, then you will probably see the following error after running sudo apachectl configtest command.

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message

To solve this problem, we can set a global ServerName in Apache. Install the Nano command-line text editor and use it to create a new configuration file.

sudo dnf install nano

sudo nano /etc/httpd/conf.d/servername.conf

Add the following line in this file.

ServerName localhost

Save and close the file. To save a file in Nano text editor, press Ctrl+O, then press Enter to confirm. To exit, press Ctrl+X. Reload Apache for the change to take effect.

sudo systemctl reload httpd

Now if you run the sudo apachectl configtest command again, you won’t see the above error message.

Step 3: Install MariaDB Database Server on CentOS 8/RHEL 8

MariaDB is a drop-in replacement for MySQL. It is developed by former members of MySQL team who are concerned that Oracle might turn MySQL into a closed-source product. Enter the following command to install MariaDB on CentOS 8/RHEL 8.

dnf install mariadb-server mariadb -y

After it’s installed, we need to start it.

systemctl start mariadb

Enable auto start at system boot time.

systemctl enable mariadb

Check status:

systemctl status mariadb

output:

● mariadb.service - MariaDB 10.3 database server
   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2019-10-12 09:02:53 UTC; 33s ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
 Main PID: 18608 (mysqld)
   Status: "Taking your SQL requests now..."
    Tasks: 30 (limit: 5092)
   Memory: 77.0M
   CGroup: /system.slice/mariadb.service
           └─18608 /usr/libexec/mysqld --basedir=/usr

“Enabled” indicates that auto start at boot time is enabled and we can see that MariaDB server is running. Now we need to run the security script.

mysql_secure_installation

When it asks you to enter MariaDB root password, press Enter key as the root password isn’t set yet. Then enter y to set the root password for MariaDB server.

Next, you can press Enter to answer all remaining questions, which will remove anonymous user, disable remote root login and remove test database. This step is a basic requirement for MariaDB database security. (Note that the letter Y is capitalized, which means it’s the default answer.)

Now you can run the following command and enter MariaDB root password to log into MariaDB shell.

mysql -u root -p

To exit, run

exit;

Step 4: Install PHP on CentOS 8/RHEL 8

Install PHP and some common modules using the following command.

dnf install php php-fpm php-mysqlnd php-opcache php-gd php-xml php-mbstring -y

Apache web server on CentOS 8/RHEL 8 by default uses PHP-FPM instead of mod_php to run PHP code, so in the above command we also installed php-fpm. After it’s installed, we need to start it.

systemctl start php-fpm

Enable auto start at system boot time.

systemctl enable php-fpm

Check status:

systemctl status php-fpm

output:

● php-fpm.service - The PHP FastCGI Process Manager
   Loaded: loaded (/usr/lib/systemd/system/php-fpm.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2019-10-12 09:54:37 UTC; 3s ago
 Main PID: 19755 (php-fpm)
   Status: "Ready to handle connections"
    Tasks: 6 (limit: 5092)
   Memory: 24.5M
   CGroup: /system.slice/php-fpm.service
           ├─19755 php-fpm: master process (/etc/php-fpm.conf)
           ├─19757 php-fpm: pool www
           ├─19758 php-fpm: pool www
           ├─19759 php-fpm: pool www
           ├─19760 php-fpm: pool www
           └─19761 php-fpm: pool www

“Enabled” indicates that auto start at boot time is enabled and we can see that PHP-FPM is running. The php-fpm package installs a php.conf file in /etc/httpd/conf.d/ directory, so we need to restart Apache web server, in order to run PHP code.

systemctl restart httpd

We also need to run the following command to tell SELinux to allow Apache to execute PHP code via PHP-FPM.

setsebool -P httpd_execmem 1

Step 5: Test PHP

To test PHP-FPM with Apache Web server, we need to create a info.php file in the document root directory.

nano /var/www/html/info.php

Paste the following PHP code into the file.

<?php phpinfo(); ?>

Save and close the file. If you installed LAMP stack on a local CentOS 8/RHEL 8 server, type in 127.0.0.1/info.php or localhost/info.php in the browser address bar. You should see your server’s PHP information. This means PHP scripts can run properly with Apache web server.

If RHEL 8/CentOS is running on a remote server, then enter server-ip-address/info.php in browser address bar. Replace sever-ip-address with your actual IP address.

If the browser fails to display the PHP info but prompt you to download the info.php file, simply restart Apache and PHP-FPM.

sudo systemctl restart httpd php-fpm

Then you should be able to see the PHP info in the web browser.

Apache Automatic Restart

If for any reason your Apache process is killed, you need to run the following command to restart it.

sudo systemctl restart httpd

Instead of manually typing this command, we can make Apache automatically restart by editing the httpd.service systemd service unit. To override the default systemd service configuration, we create a separate directory.

sudo mkdir -p /etc/systemd/system/httpd.service.d/

Then create a file under this directory.

sudo nano /etc/systemd/system/httpd.service.d/restart.conf

Add the following lines in the file, which will make Apache automatically restart 5 seconds after a failure is detected.

[Service]
Restart=always
RestartSec=5s

Save and close the file. Then reload systemd.

sudo systemctl daemon-reload

To check if this would work, kill Apache with:

sudo pkill httpd

Then check Apache status. You will find Apache automatically restarted.

systemctl status httpd

Allow Apache to Make Outgoing Network Connections

By default, SELinux forbids Apache to make outgoing network connections. If Apache needs to make requests to an outside network service, then run the following command to allow this action.

setsebool -P httpd_can_network_connect on

How to Install LAMP Stack on Debian 10 Buster Server

This tutorial is going to show you how to install Apache, MariaDB and PHP7.3 (LAMP stack) on Debian 10 Buster. A software stack is a set of software tools bundled together. LAMP stands for Linux, Apache, MariaDB/MySQL and PHP, all of which are open source and free to use. It is the most common software stack that powers dynamic websites and web applications. Linux is the operating system; Apache is the web server; MariaDB/MySQL is the database server and PHP is the server-side scripting language responsible for generating dynamic web pages.

All of the four components are free and open-source. However, since MySQL is now owned by Oracle and there’s a chance that Oracle turns it to a closed-source product, we will choose MariaDB instead of MySQL.

Prerequisites of Installing LAMP Stack on Debian 10 Buster

To follow this tutorial, you need a Debian 10 OS running on your local computer or on a remote server.

If you are looking for a VPS (Virtual Private Server), then you can register an account at Vultr via this special link to get $50 free credit (for new users only). And if you need to set up LAMP stack with a domain name, I recommend buying domain names from NameCheap because the price is low and they give whois privacy protection for free.

Please note that you need to have root privilege when installing software on Debian. You can add sudo at the beginning of a command, or use su - command to switch to root user.

Step 1: Update Software Packages

Before we install the LAMP stack, it’s a good idea to update repository and software packages. Run the following command on your Debian 10 OS.

sudo apt update

sudo apt upgrade

Step 2: Install Apache Web Server on Debian 10

Enter the following command to install Apache Web server. The apache2-utils package will install some useful utilities, such as the Apache HTTP server benchmarking tool ab and the user authentication management tool htpasswd.

sudo apt install apache2 apache2-utils

After it’s installed, Apache should be automatically started. Check its status with systemctl.

systemctl status apache2

Sample output:

● apache2.service - The Apache HTTP Server
   Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2019-07-11 13:30:35 UTC; 4min 31s ago
     Docs: https://httpd.apache.org/docs/2.4/
  Process: 17962 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
 Main PID: 17966 (apache2)
    Tasks: 55 (limit: 545)
   Memory: 4.8M
   CGroup: /system.slice/apache2.service
           ├─17966 /usr/sbin/apache2 -k start
           ├─17967 /usr/sbin/apache2 -k start
           └─17968 /usr/sbin/apache2 -k start

If it’s not running, use systemctl to start it.

sudo systemctl start apache2

It’s also a good idea to enable Apache to automatically start at boot time.

sudo systemctl enable apache2

Check Apache version:

sudo apache2 -v

Output:

Server version: Apache/2.4.38 (Debian)
Server built:   2019-04-07T18:15:40

Now type in the public IP address of your Debian 10 server in the browser address bar. You should see “It works!” Web page, which means Apache Web server is running properly. If you are installing LAMP on your local Debian 10 computer, then you should type 127.0.0.1 or localhost in the browser address bar.

If the connection is refused or failed to complete, there might be a firewall preventing incoming requests to TCP port 80. If you are using iptables firewall, then you need to run the following command to open TCP port 80.

sudo iptables -I INPUT -p tcp --dport 80 -j ACCEPT

If you are using UFW firewall, then run this command to open TCP port 80.

sudo ufw allow http

Now we need to set www-data (Apache user) as the owner of document root (otherwise known as web root). By default it’s owned by the root user.

sudo chown www-data:www-data /var/www/html/ -R

By default, Apache uses the system hostname as its global ServerName. If the system hostname can’t be resolved in DNS, then you will probably see the following error after running sudo apache2ctl -t command.

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1. Set the 'ServerName' directive globally to suppress this message

To solve this problem, we can set a global ServerName in Apache. Use the Nano command-line text editor to create a new configuration file.

sudo nano /etc/apache2/conf-available/servername.conf

Add the following line in this file.

ServerName localhost

Save and close the file. To save a file in Nano text editor, press Ctrl+O, then press Enter to confirm. To exit, press Ctrl+X. Then enable this config file.

sudo a2enconf servername.conf

Reload Apache for the change to take effect.

sudo systemctl reload apache2

Now if you run the sudo apache2ctl -t command again, you won’t see the above error message.

Step 3: Install MariaDB Database Server on Debian 10

MariaDB is a drop-in replacement for MySQL. Enter the following command to install it on Debian 10.

sudo apt install mariadb-server mariadb-client

After it’s installed, MariaDB server should be automatically stared. Use systemctl to check its status.

systemctl status mariadb

Output:

● mariadb.service - MariaDB 10.3.15 database server
   Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2019-07-11 13:57:03 UTC; 16s ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
 Main PID: 18566 (mysqld)
   Status: "Taking your SQL requests now..."
    Tasks: 31 (limit: 545)
   Memory: 73.9M
   CGroup: /system.slice/mariadb.service
           └─18566 /usr/sbin/mysqld

If it’s not running, start it with this command:

sudo systemctl start mariadb

To enable MariaDB to automatically start at boot time, run

sudo systemctl enable mariadb

Now run the post installation security script.

sudo mysql_secure_installation

When it asks you to enter MariaDB root password, press Enter key as the root password isn’t set yet. Then enter y to set the root password for MariaDB server.

Next, you can just press Enter to answer all remaining questions. This will remove anonymous user, disable remote root login and remove test database. This step is a basic requirement for MariaDB database security. (Note that the letter Y is capitalized, which means it’s the default answer.)

By default, the MaraiDB package on Debian uses unix_socket to authenticate user login, which basically means you can use username and password of the OS to log into MariaDB console. So you can run the following command to login without providing MariaDB root password.

sudo mariadb -u root

or

sudo mysql -u root

To exit, run

exit;

Check MariaDB server version information.

mariadb --version

Output:

mariadb Ver 15.1 Distrib 10.3.15-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

Step 4: Install PHP7.3 on Debian 10

At the the time of this writing, PHP7.3 is the latest stable version of PHP and has minor performance improvement over previous versions. Enter the following command to install PHP7.3 from Debian 10 repository.

sudo apt install php7.3 libapache2-mod-php7.3 php7.3-mysql php-common php7.3-cli php7.3-common php7.3-json php7.3-opcache php7.3-readline

Enable the Apache php7.3 module then restart Apache Web server.

sudo a2enmod php7.3

sudo systemctl restart apache2

Check PHP version information.

php --version

Output:

PHP 7.3.4-2 (cli) (built: Apr 13 2019 19:05:48) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.3.4, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.3.4-2, Copyright (c) 1999-2018, by Zend Technologies

To test PHP scripts with Apache server, we need to create a info.php file in the Web root directory with a command line text editor, such as Nano.

sudo nano /var/www/html/info.php

Paste the following PHP code into the file.

<?php phpinfo(); ?>

Save and close the file. (To save a file in Nano text editor, press Ctrl+O, then press Enter to confirm. To exit, press Ctrl+X.)

Now in the browser address bar, enter server-ip-address/info.php. Replace sever-ip-address with your actual IP. If you follow this tutorial on your local computer, then type 127.0.0.1/info.php or localhost/info.php.

You should see your server’s PHP information. This means PHP scripts can run properly with Apache web server. You can find that Zend OPcache is enabled.

How to Run PHP-FPM with Apache

There are basically two ways to run PHP code with Apache web server:

• Apache PHP module
• PHP-FPM.

In the above steps, the PHP7.3 module is used to handle PHP code, which is usually fine. But in some cases, you need to run PHP code with PHP-FPM instead. Here’s how.

Disable the Apache PHP7.3 module.

sudo a2dismod php7.3

Install PHP-FPM.

sudo apt install php7.3-fpm

Enable proxy_fcgi and setenvif module.

sudo a2enmod proxy_fcgi setenvif

Enable the /etc/apache2/conf-available/php7.3-fpm.conf configuration file.

sudo a2enconf php7.3-fpm

Restart Apache for the changes to take effect.

sudo systemctl restart apache2

Now if you refresh the info.php page in your browser, you will find that Server API is changed to FPM/FastCGI, which means Apache web server will run PHP code with PHP-FPM.