Configuring Apache Server in CentOS 7

Apache HTTP Server, commonly referred to as Apache, is one of the most popular web servers in the world. It is open-source, robust, and highly customizable, making it a preferred choice for hosting websites and web applications. In this guide, we will explore the step-by-step process to configure Apache on CentOS 7. By the end of this article, you will have a fully functional Apache server running on your CentOS 7 system.

Prerequisites

Before we start, ensure you have the following:

• A CentOS 7 server with root or sudo access.
• A basic understanding of command-line operations.
• An active internet connection to download packages.

Step 1: Update Your System

It is always a good practice to update your system before installing any software. This ensures you have the latest security patches and bug fixes.

This command will synchronize your system with the latest repositories.

Step 2: Install Apache HTTP Server

Apache is available in CentOS’s default YUM repositories, which makes installation straightforward.

1. To install Apache, run:

   bash

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   sudo yum install httpd -y

2. Once the installation is complete, verify the Apache version:

   bash

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   httpd -v

   You should see output indicating the version of Apache installed, e.g., Apache/2.4.6.

Step 3: Start and Enable Apache Service

After installation, you need to start the Apache service and enable it to start automatically on boot.

1. Start the Apache service:

   bash

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   sudo systemctl start httpd

2. Verify that Apache is running:

   bash

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   sudo systemctl status httpd

   The output should indicate that the service is active and running.

3. Enable Apache to start on boot:

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   sudo systemctl enable httpd

Step 4: Configure Firewall to Allow HTTP and HTTPS Traffic

By default, CentOS 7 uses firewalld to manage firewall rules. You need to allow HTTP and HTTPS traffic to access your web server.

1. Check the current firewall state:

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   sudo firewall-cmd --state

   If it’s running, proceed to configure it.

2. Allow HTTP service:

   bash

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

3. Allow HTTPS service (if SSL is required):

   bash

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

4. Reload the firewall to apply changes:

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   sudo firewall-cmd --reload

Step 5: Test Apache Installation

To confirm Apache is working, you can open a web browser and visit your server's IP address. For example:

If Apache is installed and running, you should see the default CentOS 7 Apache test page.

Step 6: Configure Virtual Hosts

Virtual hosts allow you to host multiple websites on a single server. This is useful for shared hosting environments.

1. Create a Directory for Your Website Let’s assume your domain is example.com. Create a directory to store your website’s files:

   bash

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   sudo mkdir -p /var/www/example.com

2. Set Permissions Assign ownership of the directory to the Apache user:

   bash

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   sudo chown -R apache:apache /var/www/example.com

   Set the correct permissions:

   bash

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   sudo chmod -R 755 /var/www/example.com

3. Create a Virtual Host Configuration File Create a configuration file for your site:

   bash

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   sudo nano /etc/httpd/conf.d/example.com.conf

   Add the following content to the file:

   apache

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   <VirtualHost *:80> ServerAdmin admin@example.com DocumentRoot /var/www/example.com ServerName example.com ServerAlias www.example.com <Directory /var/www/example.com> Options Indexes FollowSymLinks AllowOverride All Require all granted </Directory> ErrorLog /var/log/httpd/example.com-error.log CustomLog /var/log/httpd/example.com-access.log combined </VirtualHost>

4. Test Apache Configuration Verify that the configuration file is correct:

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   sudo apachectl configtest

   If the syntax is correct, you’ll see Syntax OK.

5. Restart Apache Apply the changes by restarting Apache:

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   sudo systemctl restart httpd

Step 7: Configure SELinux (If Enabled)

Security-Enhanced Linux (SELinux) might block Apache from accessing your website’s directory. To avoid this, configure the appropriate SELinux rules.

1. Verify SELinux status:

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   sestatus

2. If SELinux is enforcing, update the file context:

   bash

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   sudo semanage fcontext -a -t httpd_sys_content_t "/var/www/example.com(/.*)?" sudo restorecon -R /var/www/example.com

Step 8: Enable .htaccess (Optional)

The .htaccess file is used for per-directory configuration, such as enabling URL rewriting. To use .htaccess, ensure AllowOverride All is set in your virtual host configuration.

1. Edit your virtual host file:

   bash

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   sudo nano /etc/httpd/conf.d/example.com.conf

2. Confirm the AllowOverride All directive is set:

   apache

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   <Directory /var/www/example.com> AllowOverride All </Directory>

3. Restart Apache:

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   sudo systemctl restart httpd

Step 9: Configure SSL for Secure Connections (Optional)

For HTTPS support, you need an SSL certificate. Let’s configure a free SSL certificate from Let’s Encrypt using Certbot.

1. Install Certbot:

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   sudo yum install epel-release -y sudo yum install certbot python-certbot-apache -y

2. Obtain an SSL certificate:

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   sudo certbot --apache -d example.com -d www.example.com

3. Follow the prompts to configure SSL automatically.

4. Verify SSL configuration by visiting:

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   https://example.com

5. Set up automatic certificate renewal:

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   sudo crontab -e

   Add the following line to renew certificates automatically:

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   0 0 * * * certbot renew --quiet

Step 10: Monitor and Manage Apache

Logs

Monitor Apache logs for errors and access information:

• Error log: /var/log/httpd/error_log
• Access log: /var/log/httpd/access_log

Status

Check Apache status:

Restart/Stop/Start

• Restart:
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  sudo systemctl restart httpd
• Stop:
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  sudo systemctl stop httpd
• Start:
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  sudo systemctl start httpd

Conclusion

You have successfully configured an Apache web server on CentOS 7. This guide covered the installation, basic configuration, virtual hosts, SSL setup, and firewall adjustments. With this setup, you are ready to host websites or web applications. For advanced configurations, refer to the official Apache documentation and experiment with modules and performance tuning.