Simple Demo Applications

By Brian

May 4, 2021

When doing a customer demo, I often need a simple app. Generally I am discussing the infrastructure – Elastic Load Balancer, API Gateway, etc – and the application is unimportant. I have found that phpinfo is a great sample application because it shows the headers received by the server. This allows me to see x-forwarded-for headers, etc. On Windows, ASP.NET Tracing provides similar results. Keep in mind that these utilities expose a lot of info about your environment so use them wisely.

Linux

PHP provides a function phpinfo() that will returns a ton of info about the PHP environment. A simple page that includes the following is all you need. For example:

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<?php phpinfo(); ?>

Here is an EC2 user data script that will install Apache and PHP and create the simple page. I have tested this on Amazon Linux 2, but it should work on any Fedora derivative.

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#! /bin/bash
yum install -y httpd php
echo '<?php phpinfo(); ?>' > /var/www/html/index.php
systemctl start httpd
systemctl enable httpd

Docker

The standard PHP image on Docker Hub supports phpinfo. You just need to create a PHP page that calls phpinfo(). My Dockerfile looks like this.

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FROM php:apache
RUN echo '<?php phpinfo(); ?>' > /var/www/html/index.php

The original image includes the entry point and exposes Apache in port 80. Therefore, you you can build and run locally like this.

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docker build . -t phpinfo
docker run -d -p 8080:80 phpinfo 

Windows

ASP.NET (Legacy .NET Framework) provides a similar option. You simply add Trace="true" to the page directive. For example:

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<%@ Page Title="" Language="C#" Trace="true"%>

Here is an EC2 user data script that will install IIS and create a simple page with tracing. I have tested this on Windows 2019, but it should work on any Windows version.

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<powershell>
Install-WindowsFeature -Name Web-Server -IncludeAllSubFeature
Add-Content 'c:\inetpub\wwwroot\default.aspx' '<%@ Page Title="" Language="C#" Trace="true"%>'
Remove-Item 'c:\inetpub\wwwroot\iisstart.htm'
</powershell>