How to Install Apache on Linux Servers | Complete Tutorial

Installing Apache on Linux servers at IOFLOOD is a fundamental step in setting up a robust web server environment. Apache, also known as Apache HTTP Server, is one of the most widely used web servers globally, known for its stability, security, and versatility. This guide aims to provide a concise yet comprehensive tutorial for our customers and fellow developers on installing Apache on their dedicated Linux cloud servers to create reliable web hosting solutions.

In this guide, we will walk you through the process of installing Apache on Linux. We will provide instructions for both APT (Debian and Ubuntu) and YUM-based distributions (CentOS and AlmaLinux), delve into compiling Apache from source, installing a specific version, and finally, how to use the Apache server and ensure it’s installed correctly.

So, let’s get started and begin installing Apache on your Linux system!

TL;DR: How Do I Install Apache on Linux?

You can install Apache on Ubuntu by running the command sudo apt-get install apache2. For CentOS and similar OSs, use the command sudo yum install httpd.

# For Ubuntu and Debian based systems
sudo apt-get update
sudo apt-get install apache2

# For CentOS and similar systems
sudo yum update
sudo yum install httpd

# Output:
# 'apache2/httpd is already the newest version (2.4.29-1ubuntu4.14).'
# '0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.'

This is just a basic way to install Apache on Linux, but there’s much more to learn about installing and using Apache. Continue reading for more detailed information and advanced usage scenarios.

Getting Started with Apache on Linux

Apache, also known as the Apache HTTP Server, is a free and open-source cross-platform web server. It’s renowned for its reliability, robustness, and rich feature set. Apache plays a crucial role in serving a significant portion of all web traffic worldwide. It’s used to host anything from personal blogs to high traffic websites.

Now, let’s explore how to install Apache on Linux. We’ll cover the installation process using two popular package managers: APT (used in Debian-based distributions) and YUM (used in Red Hat-based distributions).

Installing Apache with APT

If you’re using a Debian-based distribution like Ubuntu, you’ll use the APT package manager to install Apache. Here’s how you can do it:

# Update your package lists
sudo apt-get update

# Install Apache2 package
sudo apt-get install apache2 -y

# Output:
# 'apache2 is already the newest version (2.4.29-1ubuntu4.14).'
# '0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.'

In this example, we first update the package lists for upgrades and new package installations. Next, we install Apache using the sudo apt-get install apache2 -y command. The -y option automatically confirms the installation, saving you an extra step.

Installing Apache with YUM

If you’re using a Red Hat-based distribution like CentOS, you’ll use the YUM package manager. Here’s the command sequence:

# Update your system
sudo yum update -y

# Install Apache
sudo yum install httpd -y

# Output:
# 'Package httpd-2.4.6-93.el7.centos.x86_64 already installed and latest version'
# 'Nothing to do'

In this case, we first update the system with sudo yum update -y. Next, we install Apache using sudo yum install httpd -y. The package name for Apache in Red Hat-based distributions is ‘httpd’.

Installing Apache from Source

Sometimes you might need to install Apache from source. This could be due to the need for a specific version not available in your distribution’s repositories, or you might want to customize the build parameters. Here’s how you can do it:

# Download Apache source code
wget http://apache.mirrors.ionfish.org//httpd/httpd-2.4.46.tar.gz

# Extract the tarball
tar xzf httpd-2.4.46.tar.gz

# Navigate into the extracted directory
cd httpd-2.4.46/

# Configure the source
./configure --prefix=/usr/local/apache2

# Compile the source code
make

# Install Apache
sudo make install

In this example, we first download the Apache source code using wget. Next, we extract the tarball using tar xzf. We then navigate into the extracted directory and configure the source to be installed in /usr/local/apache2. Finally, we compile the source code using make and install it using sudo make install.

Installing Specific Versions

From Source

If you need to install a specific version of Apache, you can do so by downloading the appropriate source tarball. For example, to install version 2.4.46, you would replace httpd-2.4.46.tar.gz in the previous example with the tarball for your desired version.

Using Package Managers

APT

On Debian-based distributions, you can install a specific version of a package using the apt-get install package=version syntax. However, only versions available in your configured repositories can be installed this way.

YUM

On Red Hat-based distributions, you can use the yum install package-version syntax to install a specific version of a package. As with APT, only versions available in your configured repositories can be installed this way.

Version Comparison

Different versions of Apache have different features and compatibilities. For instance, version 2.4 introduced many changes, such as improved performance and reduced memory usage. Here’s a brief comparison:

Basic Apache Usage and Verification

Using Apache

Once Apache is installed, you can start it with the following command:

sudo apachectl start

Verifying Installation

To verify that Apache is installed and running, you can use the curl command to fetch the default Apache page:

curl localhost

# Output:
# '<html><body><h1>It works!</h1></body></html>'

This command sends a request to your own machine, which should be served by Apache, returning the default ‘It works!’ page.

Exploring Alternative Web Servers

While Apache is a powerful and popular web server, it’s not the only option available. Another widely used web server is Nginx. It’s renowned for its high performance, stability, rich feature set, simple configuration, and low resource consumption.

Installing Nginx on Linux

Much like Apache, you can install Nginx using the package manager of your Linux distribution. Here’s how to do it:

# For Ubuntu and Debian based systems
sudo apt-get update
sudo apt-get install nginx -y

# For CentOS and similar systems
sudo yum update -y
sudo yum install nginx -y

# Output:
# 'nginx is already the newest version (1.14.0-0ubuntu1.7).'
# '0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.'

In this example, we first update the system. Next, we install Nginx using the sudo apt-get install nginx -y or sudo yum install nginx -y command, depending on our Linux distribution.

Nginx vs Apache

Both Apache and Nginx have their own strengths and weaknesses. While Apache’s .htaccess allows for powerful directory-level configuration, it can lead to a performance hit. On the other hand, Nginx’s event-driven architecture can handle a large number of simultaneous connections with minimal memory usage.

Here’s a brief comparison:

Making the Choice

Choosing between Apache and Nginx depends on your specific needs. If you need .htaccess and prefer a simpler configuration, Apache might be the way to go. However, if you’re expecting high traffic and need to conserve resources, Nginx might be a better choice.

Troubleshooting Installations: Apache

While installing Apache on Linux is generally straightforward, you may encounter some issues. Here’s a discussion of common problems and their solutions.

Apache Service Doesn’t Start

Sometimes, you may find that the Apache service doesn’t start after installation. This could be due to a variety of reasons, such as port 80 (the default HTTP port) being occupied by another service.

To troubleshoot, you can check the status of the Apache service:

# For Debian-based distributions
sudo service apache2 status

# For CentOS and similar systems
sudo service httpd status

# Output:
# 'apache2.service - The Apache HTTP Server'
# 'Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)'
# 'Active: active (running) since Tue 2022-01-25 11:43:47 UTC; 1 day 4h ago'

If the service isn’t running, you can try to start it manually and check for any error messages.

Configuration Errors

Configuration errors can also prevent Apache from starting. These errors usually result from syntax errors in your configuration files.

You can check your Apache configuration for syntax errors with the following command:

# For Debian-based distributions
sudo apachectl configtest

# For CentOS and similar systems
sudo httpd -t

# Output:
# 'Syntax OK'

If there’s a syntax error, the command will output an error message pointing to the location of the problem.

Permission Issues

Permission issues can also lead to problems when running Apache, especially if you’re trying to serve files from a directory that Apache doesn’t have access to.

To fix this, you can change the permissions of the directory with the chmod command:

sudo chmod -R 755 /path/to/your/directory

# Output:
# No output if the command is successful

In this example, we’re giving read and execute permissions to the user and the group, and only the owner can write to the directory.

Remember, troubleshooting is a process of elimination. Keep patient, and methodically work through any issues, and you’ll have your Apache server up and running in no time.

Understanding Web Servers

Before we delve further into Apache’s role in web hosting, it’s essential to understand what a web server is and why it’s so crucial.

A web server is a system that processes incoming network requests over HTTP (HyperText Transfer Protocol) and several other related protocols. The primary job of a web server is to display website content to users. Whenever you’re browsing the web, your browser is constantly sending requests to web servers, which in turn deliver the website’s pages to your device.

The Role of Apache in Web Hosting

Apache is one of the most widely used web servers in the world. It’s an open-source software, which means it’s free to use and continuously improved by a community of developers. Apache serves as the delivery man of the internet, fetching the right web pages for each user’s requests.

# Example of a request to an Apache server

curl -I http://example.com

# Output:
# HTTP/1.1 200 OK
# Date: Wed, 26 Jan 2022 13:58:24 GMT
# Server: Apache/2.4.46 (Ubuntu)
# Last-Modified: Mon, 24 Jan 2022 13:58:24 GMT
# Content-Type: text/html

In the example above, we use the curl command to send a request to example.com. The -I option tells curl to only fetch the headers. From the response headers, we can see that the server is running Apache 2.4.46 on Ubuntu.

Apache’s role in web hosting is critical. It’s responsible for serving static content (like HTML pages, images, and stylesheets) and can also serve dynamic content through various modules and integrations with other software. Apache’s modularity, robustness, and rich feature set have made it a favorite among many web developers and system administrators.

The Relevance of Apache

Apache continues to be a reliable choice for web development and hosting. Its flexibility, robustness, and active community make it a viable choice for many developers and system administrators. Whether you’re hosting a small personal blog or a high-traffic commercial site, Apache has the tools and features to meet your needs.

Diving Deeper: SSL Certificates and .htaccess Files

Once you have your Apache server up and running, there are many more topics to explore. Two of these are SSL certificates and .htaccess files.

SSL certificates are used to secure communications between the server and the client. They are essential for protecting sensitive information and are a must for any site dealing with personal or financial data.

# Example: Enabling SSL module in Apache
sudo a2enmod ssl

# Output:
# 'Enabling module ssl.'
# 'See /usr/share/doc/apache2/README.Debian.gz on how to configure SSL and create self-signed certificates.'
# 'To activate the new configuration, you need to run: systemctl restart apache2'

In this example, we enable the SSL module in Apache using the sudo a2enmod ssl command. This is the first step in setting up SSL on your Apache server.

.htaccess files are a powerful feature of Apache that allow you to configure settings on a per-directory basis. This can be useful for setting up redirects, rewriting URLs, and controlling access to your site.

# Example: Creating a .htaccess file
echo 'RewriteEngine On' > .htaccess

# Output:
# No output if the command is successful

In this example, we create a .htaccess file and enable the rewrite engine. This is a common use of .htaccess files and is the first step in setting up URL rewriting.

Further Resources for Apache Mastery

Learning to install and configure Apache is just the beginning. To help you continue your journey, here are some resources that provide more in-depth information:

• The Apache HTTP Server Project: The official website of the Apache HTTP Server Project. It’s a treasure trove of information, with extensive documentation and user forums.

• Apache Server Admin for Beginners: A Udemy course that covers Apache administration in depth. While it’s not free, it often goes on sale.

• DigitalOcean’s Apache Tutorials: A series of tutorials from DigitalOcean that cover Apache and related topics.

Recap: Install Apache Web Server

In this comprehensive guide, we’ve ventured through the process of installing Apache on Linux, a powerful and widely-used web server. We’ve not only covered the basics but also delved into advanced topics, providing you with a robust understanding of Apache and its installation on Linux.

We began with the basics, demonstrating how to install Apache on Linux using popular package managers like APT and YUM. We then delved into more advanced topics, such as installing Apache from source and installing specific versions, providing you with the flexibility to tailor Apache to your specific needs.

Along the journey, we tackled common challenges you might encounter when installing Apache on Linux, such as service start-up issues, configuration errors, and permission issues, providing you with solutions for each problem.

We also explored alternative approaches to setting up a web server on Linux, introducing you to Nginx, a high-performance web server that could be a viable alternative depending on your specific needs. Here’s a quick comparison of these web servers:

Whether you’re just starting out with Apache or looking to deepen your understanding, we hope this guide has provided you with a deeper insight into installing Apache on Linux and its alternatives.

With its robustness and rich feature set, Apache continues to be a reliable choice for web hosting. Now, you’re well-equipped to install Apache on your Linux system and start serving web pages to your users. Happy hosting!