November 10, 2019 / Other tutorialsThe Apache HTTP Server, an open-source web server developed by the Apache Software Foundation. The Apache server is used to host web content. It responds to requests for content from web browsers, such as Internet Explorer and Firefox. The Apache HTTP Server ('httpd') was launched in 1995 and it has been the most popular web server on the Internet since April 1996. It has celebrated its 25th birthday as a project in February 2020. The Apache HTTP Server is a project of The Apache Software Foundation. Apache httpd 2.4.46 Released 2020-08-07 ¶. Apache is a popular open-source, cross-platform web server that is, by the numbers, the most popular web server in existence. It’s actively maintained by the Apache Software Foundation. Some high-profile companies using Apache include Cisco, IBM, Salesforce, General Electric, Adobe, VMware, Xerox, LinkedIn, Facebook, Hewlett-Packard, AT&T.
Most of the internet is based on web server software. Basically, a web server retrieves content from local storage and delivers it to the client. In this article, we will show some web server examples.
Apache Web Server
Apache is currently the most used web server in the world. Founded in 1996, it’s now maintained by the Apache Foundation. It’s freeware, and compatible with Linux, Windows, FreeBSD, Mac and several other platforms.
Copahost uses Apache on almost all of its web hosting servers.
IIS
Also one of the most popular web server examples. IIS belongs to Microsoft. IIS stands for Microsoft Internet Information Services. It comes with the Windows Server operating system. It’s configurable through a graphical interface.
NGINX
It’s one of the most popular web server software. NGINX was developed by Igor Sysoev in 2002. Also, it is not a standalone web server example. NGINX is a different example because it works as a proxy server, together with another web server application like Apache.
It was developed to handle hundreds of concurrent connections, delivering better performance. Meant to be a load-balanced web server for heavy applications. Also, it claims to be responsible for 66% of the busiest sites.
Apache Tomcat
Tomcat is a free web server, specialized in Java Servlets. In other words, it’s a Java container. Apache Tomcat was initially developed by Sun Microsystems, and then it was transferred to the Apache Software Foundation in 1999. By the way, Tomcat usually works under port 8080 and supports PHP, ASP.net, Perl, Python, etc.
Lighthttpd
Lighthttpd was initially developed in 2003. Basically, it’s not a very common web server software example for public web sites on the internet. It has a big advantage: as the name says, it’s the lighter HTTP server available. It uses a very low memory, CPU and disk space.
Internet routers, web cameras, and other small hardware use Lighthttpd as their web server.
Conclusion about web server examples
There are many web servers available. Basically, IIS is one of the few paid software. Web server prices may vary. Apache is the most used web server, and it’s the one preferred by Copahost to host its customers. Large web sites with too much traffic generally use NGINX.
Apache Tomcat had more market in the past, as Java Containers are not very used nowadays. And Lighthttpd is a great software to be used as a local web server, or for small web hosting projects.
In this tutorial we install Apache web server in Raspberry Pi to control the LED from a webpage that can be accessed from anywhere over the internet. This is a basic tutorial with minimum features and it can be further modified to use this method in IoT based home automation, remote control automation, robotics etc.
Here we control an LED, connected to Raspberry Pi by using Apache web server. For this we create an html/php web page which has two buttons - one for turning on the LED and second for turning off the LED.
Components Required
- Raspberry pi board (With Raspbian operating system)
- LED
- 250 ohm resistor
- Jumper Wires
A SSH client (Putty) is used to connect the Raspberry pi using Laptop or computer. For this the raspberry pi needs be connected to network via LAN or Wi-Fi. If you have a separate monitor for your raspberry pi, then it's better to connect raspberry pi with monitor and you don’t have to use any SSH client.
Controlling LED using Raspberry Pi Webserver
Step 1 Connections
The connections in this project are quite simple - positive pin of LED is connected to GPIO 27 pin and the negative to a 270 ohm resistor, the other side of which is connected to GND pin.
Step 2: Installing WiringPi Library
WiringPi is a PIN based GPIO access library written in C for the BCM2835, BCM2836 and BCM2837 SoC devices used in all Raspberry Pi versions. It’s released under the GNU LGPLv3 license and is usable from C, C++ and RTB (BASIC) as well as many other languages with suitable wrappers.
1. First we will update our Pi with latest versions of Raspbian using the command:
2. Now we will install git by using this command:
3. Now obtain WiringPi using git by this command:
4. Then install WiringPi library using:
Step 3: Installing a Web Server
Apache is a very popular webserver, designed to create web servers that have the ability to host one or more HTTP-based websites. Apache Web Server can be enhanced by manipulating the code base or adding multiple extensions/add-ons. In our project we are using an HTTP server and it's PHP extension.
To Install Apache web server we will use following commands:
First, update the available packages :
Now, install the apache2 package by using this command command in terminal:
To test the web server whether it is working or not, go to your browser and type the Pi’s IP address in the tab. To find the Pi's IP address, type ifconfig at the command line.
By default, Apache puts a test HTML file in the web folder. This default web page is served when you browse to http://192.168.1.31 (whatever the Pi's IP address is) from another computer on the network.
Browse to the default web page either on the Pi or from another computer on the network and you will see the following:
This means Apache web server is working.
Now we will see how to Change the default web page with your own HTML page
This default web page is just an HTML file on the filesystem. It is located at var/www/html/index.html.
Navigate to this directory in a terminal window and have a look at what's inside:
This shows that by default there is one file in /var/www/html/ called index.html and it is owned by the root user . To edit the file, you need to change its ownership to your own username. Change the owner of the file using:
Python Apache Web Server Example
You can now try editing this file and then refresh the browser to see the web page change.
PHP Installation in Raspberry pi
Now if we want to use PHP code along with HTML then we have to further install the PHP extension in Raspberry pi. Using PHP code we can create shell commands to control the LED from PHP script.
Apache Web Server Example Software
To allow Apache server to edit PHP files, we will install the latest version of PHP and the PHP module for Apache. Use the following command in terminal to install these:
Now remove the default index.html file:
And create the your own index.php file:
Apache Web Server History
Now enter the below code in index.php to test the PHP installation.
Save it by pressing CTRL + X and the ‘y’ and enter. Now refresh the webpage in your browser you will see a long page with lots of information about PHP. This shows that the PHP extension is installed properly. If you have any problem to the pages or if the pages do not appear try reinstalling apache server and its PHP extension.
Step 5: Start Coding for controlling GPIO pin using this Raspberry Pi Webserver
Now delete the previous code in index.php (<?php phpinfo(); ?>) file and insert below PHP code to control GPIO pins inside body of HTML code.
Below is the complete code for creating two buttons to turn on and off the LED connected to Raspberry Pi.
In above code there is a PHP script which checks which button is pressed by using below code and then turns on and off the LED accordingly.
Here we have used shell_exec() command in php code, this command is used to run the shell command from the PHP script. Learn more about shell_exec here. If you run the command inside shell_exec directly form the terminal of Raspberry pi, you can directly make GPIO pin 27 low or high. Below are two commands to test the LED directly from terminal.
After completing this, run the code in your browser by typing the IP address of raspberry pi in the browser. You will see 2 buttons - ON, OFF to control your LED by clicking these buttons.