Introduction

Apache is a popular Linux-based web server application. It is part of the LAMP stack (Linux, Apache, MySQL, PHP) that powers much of the internet.

This guide will show you how to install Apache on CentOS 8.

Prerequisites

• A system running CentOS 8 Linux
• Access to a terminal window / command line (Ctrl–Alt–F2)
• A user account with sudo or root privileges

Installing Apache Web Server on CentOS 8

Step 1: Update Software Repository

Open a terminal window, and update the repository package lists by entering the following:

sudo yum update

Step 2: Install Apache

Now you can install Apache with the command:

sudo yum –y install httpd

Step 3: Start and Manage Apache Web Server

Apache is a service that runs in the background.

Start the Apache service by entering the following:

sudo systemctl start httpd

The system doesn’t return an output if the command is run properly.

To configure Apache to run on startup:

sudo systemctl enable httpd

To check the status of the Apache service:

sudo systemctl status httpd

To reload Apache (reloads configuration files to apply changes):

sudo systemctl reload httpd

To restart the entire Apache service:

sudo systemctl restart httpd

To stop Apache:

sudo systemctl stop httpd

To disable Apache at system startup:

sudo systemctl disable httpd

Step 4: Test Apache Web Server

Your Apache software’s job is to serve web pages over a network. Your new Apache installation has a default test page, but you can also create a custom test page.

Check the Default Apache Test Page

In a terminal window, find your system’s IP address with the following:

hostname -I | awk '{print $1}'

If you’re familiar with the ip addr show or ifconfig commands, you can use those instead.

Open a web browser and type in the IP address displayed in the output. The system should show the Apache HTTP Server Test Page, as seen in the image below:

If your system doesn’t have a graphical interface, use the curl command:

curl [your_system's_IP_address]:80

Optional: Create an HTML File to Test

If, for some reason, you need or have a custom HTML page you want to use as a test page, do the following:

In a terminal window, create a new HTML index file:

echo My Apache Web Server on CentOS 8 > /var/www/html/index.html

Edit the file to your liking and save it.

Now you can follow the steps in the previous section (check your IP address and browse to it in a web browser or use the curl command).

Your Apache server is working correctly if it displays the specified custom page.

Step 5: Adjust Firewall for Apache

The firewall on your system blocks traffic on different ports. Each port has a number, and different kinds of traffic use different ports. For your web server, you’ll need to allow HTTP and HTTPS traffic on ports 80 and 443 (respectively).

In a terminal, enter the following:

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

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

Restart firewalld:

sudo firewall-cmd --reload

Double-check to make sure your firewall is correctly configured:

sudo firewall-cmd --list-all | grep services

You should see http and https in the list of allowed services.

Apache also offers ModSecurity, a plug-in module that works as a firewall. You can install and configure ModSecurity as an additional safety layer, which helps you monitor traffic and respond to any irregularities.

Apache Files and Directories

Apache is controlled by applying directives in configuration files:

• /etc/httpd/conf/httpd.conf – Main Apache config file
• /etc/httpd/ – Location for all config files
• /etc/httpd/conf.d/ – All config files in this directory are included in the main confog file
• /etc/httpd/conf.modules.d/ – Location for Apache module config files

Diligently check Apache log files to monitor your web server:

• /var/log/httpd/ – Location of Apache log files
• /var/log/httpd/access_log – Shows a log of systems that accessed the server
• /var/log/httpd/error_log – Shows a list of any errors Apache encounters

Designate a directory to store the files for your website. Use the configuration files to point to the directory you choose. Some typical locations include:

• /home/username/my_website
• /var/www/my_website
• /var/www/html/my_website
• /opt/my_website

Conclusion

You should now have a working Apache web server on your CentOS system. Next, you may be interested in installing a full LAMP stack.

sudo dnf install httpd

sudo systemctl start httpd
sudo systemctl enable httpd

sudo systemctl status httpd

● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2020-08-17 11:45:17 UTC; 1min 10s ago
     Docs: man:httpd.service(8)
 Main PID: 809 (httpd)
    Tasks: 213 (limit: 4704)
   Memory: 33.3M
   CGroup: /system.slice/httpd.service
           ├─809 /usr/sbin/httpd -DFOREGROUND
           ├─810 /usr/sbin/httpd -DFOREGROUND
           ├─811 /usr/sbin/httpd -DFOREGROUND
           ├─812 /usr/sbin/httpd -DFOREGROUND
           └─813 /usr/sbin/httpd -DFOREGROUND

Aug 17 11:45:17 centos8 systemd[1]: Starting The Apache HTTP Server...
Aug 17 11:45:17 centos8 systemd[1]: Started The Apache HTTP Server.

sudo firewall-cmd --add-service=http --permanent
sudo firewall-cmd --reload

sudo firewall-cmd --list-all

public (active)
  target: default
  icmp-block-inversion: no
  interfaces: ens3
  sources:
  services: dhcpv6-client http ssh
  ports:
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules: