Fall 2016, CS-160 Handout: How to install and configure the Apache web server on Linux Mint

How to install and configure the Apache web server on Linux Mint
CS-160: Software Engineering
Instructor: Rob Bruce
Fall 2016

OBJECTIVE: to install and configure Apache web server with the Common Gateway Interface (CGI) on Linux Mint.

Launch a terminal window (also known as a command line prompt or shell).

Step 1 of 15: In terminal window, log in as root

In your terminal window type the following at the command prompt: su
You will be prompted to enter the root password. Enter that password.
Your terminal window should now display a "#" (hash mark) prompt. This indicates you are logged in as root!

Step 2 of 15: update software library cache

First we need to update our cache of software libraries that are available to install or update.
In your terminal window type the following at the command prompt (you should be root): apt-get update

Step 3 of 15: install Apache

Now that we've updated our cache, the next step is to install the Apache web server.
In your terminal window type the following at the command prompt (you should be root): apt-get install apache2

Step 4 of 15: Enable PHP in Apache.

In your terminal window type the following at the command prompt (you should be root): apt-get install php7.0 libapache2-mod-php7.0

Step 5 of 15: Enable the Common Gateway Interface (CGI) in Apache.

In your terminal window type the following at the command prompt (you should be root): a2enmod cgi

Step 6 of 15: Restart the Apache server.

In your terminal window type the following at the command prompt (you should be root): service apache2 restart

Step 7 of 15: Verify that the Apache web server is running.

Point your browser to the following URL at http://localhost
Your browser should display a page that looks like this:

Step 8 of 15: Create a test PHP program.

Select then copy (<ctrl><c> is hotkey for copy in Linux) the following text:

<?php phpinfo(); ?>

Step 9 of 15: Paste the PHP program into the Apache web directory

In your terminal window type the following at the command prompt (you should be root): cat > /var/www/html/test.php
In your terminal window (you should be root) press <ctrl><shift><v> to paste the previously selected text
In your terminal window (you should be root) press <ctrl><d>. Press <ctrl><d> again.
You should now have a program saved in /var/www/html/test.php

Step 10 of 15: Change owner and group permissions for PHP program

For security reasons, no PHP programs should be owned by root or have group editing privileges as root.
In your terminal window (you should be root) enter the following text: chown www-data:www-data /var/www/html/test.php
In your terminal window (you should be root) enter the following text: chmod 755 /var/www/html/test.php

Step 11 of 15: Verify that the Apache web server will execute PHP program encoded web content

Point your browser to the following URL at http://localhost/test.php
Your browser should display a page that looks similar to this:

Step 12 of 15: Create a test CGI program in Python.

Note: All cgi-bin applications (interactive web page content generated dynamically) are located on your computer at the following path:
/usr/lib/cgi-bin/
Select then copy (<ctrl><c> is hotkey for copy in Linux) the following text:

#!/usr/bin/python print "Content-type:text/html\r\n\r\n" print '<html>' print '<head>' print '<title>Python program in cgi-bin</title>' print '</head>' print '<body>' print '<h2>This Python program is running from the cgi-bin directory.</h2>' print '</body>' print '</html>'

Step 13 of 15: Paste the Python program into the cgi-bin directory

In your terminal window type the following at the command prompt (you should be root): cat > /usr/lib/cgi-bin/test.cgi
In your terminal window (you should be root) press <ctrl><shift><v> to paste the previously selected text
In your terminal window (you should be root) press <ctrl><d>. Press <ctrl><d> again.
You should now have a program saved in /usr/lib/cgi-bin/test.cgi

Step 14 of 15: Change owner and group permissions

For security reasons, no cgi-bin programs should be owned by root or have group editing privileges as root.
In your terminal window (you should be root) enter the following text: chown www-data:www-data /usr/lib/cgi-bin/test.cgi
In your terminal window (you should be root) enter the following text: chmod 755 /usr/lib/cgi-bin/test.cgi

Step 15 of 15: Test access to your cgi-bin application with your web browser

Point your browser to the following URL at http://localhost/cgi-bin/test.cgi
You should see output like this:
This Python program is running from the cgi-bin directory.

Miscellaneous notes:

All web documents (including PHP encoded web documents) are located on your computer at the following path
/var/www/html
For example, when you type the URL at http://localhost/index.html, Apache is accessing index.html located on your computer at the following path:
/var/www/html/index.html
Alternately, when you type the URL at http://localhost/test.php, Apache is accessing test.php located on your computer at the following path:
/var/www/html/test.php
All cgi-bin applications are located on your computer at the following path:
/usr/lib/cgi-bin/
For example, when you type the URL at http://localhost/cgi-bin/test.cgi, Apache is accessing test.cgi located on your comptuer at the following path:
/usr/lib/cgi-bin/test.cgi
You can create dynamic web and process form data either through the Common Gateway Interface directory (cgi-bin) or through the PHP interpreter enabled in Apache.
You should make sure all static web pages, all PHP web pages, and all cgi-bin programs are owned by www-data with group access for www-data. Lastly, you should make sure all PHP content or cgi-bin content should be set to read and execute only with NO write permissions (i.e. chmod 755).