Recently we put a disaster preparedness kit that acted as a Drupal website on a usb thumb drive for the American Institute of Architects’ Communities by Design Initiative. This meant getting the entire Apache+php+MySQL stack running from the usb drive and essentially acting as a web server on a stick. Installing a web server is almost never as simple of a task as you’d expect no matter how often you do it, especially when it needs to be set it up on the fly from any computer. 

There are several platforms that thankfully provide fully contained web server environments that make this process much easier. Among us Mac developers MAMP is very popular, and on the Windows side platforms like XAMMP and the Uniform Server work well. For this project we started from XAMMP, and it got us fairly close right out of the box. However, there were some drawbacks – it was big, and it assumed some things we didn’t like. So we made some performance tweaks, most importantly enabling and configuring a php cache, to speed things up. We also created some additional nice features like custom start up scripts and icons. With this, the server was set up for Windows users.

Here is a screencast showing how it runs off the stick. I’ll explain how we did it here to hopefully save other developers some time below.

Next we needed to set it up for Macs. We didn’t want to sacrifice any functionality on the Windows side when we set up the stick for Macs, since most users would access the kit from Windows. This is always a little tricky. We weren’t interested in providing two completely separate applications. We wanted the same information to be available for everyone, no matter if they used Windows or a Mac, and this means sharing the database and user files between both operating systems.

So we started with the MAMP package to get the kit working on Macs, and similarly to what we did with XAMMP, we stripped and reworked it to behave nicely on a usb stick. The MAMP package is hard coded to run from a very specific location on a Mac, and that location isn’t a usb disk. We needed to touch every configuration file and all of the MySQL and Apache start and stop scripts to make it work from the stick. Additionally there were some extra niceties in the MAMP package that we just removed, as we didn’t need them and they just took up space. One unexpected issue we came across was formatting the stick. Windows disk formats (FAT16 & FAT32) don’t work the same way as Mac and Unix disk formats, and very importantly they don’t have the notion of “sockets.” A socket is how two Unix programs talk to each other, and in our Apache+PHP+MySQLstack it’s how MySQL communicates with php. Without this link, Drupal can’t run.

So this could have been a show stopper for Mac compatibility, but we couldn’t have that. We discussed several possible solutions and eventually settled on adding an HFS+ partition to the USB sticks. This partition is totally invisible to Windows users and provides a place for MySQL to put its “socket.” And by sharing the FAT16 part of the drive, we’re able to share all the application files – both Drupal’s php files and the MySQL databases. This means that if you make an update on a PC, that same update will show up on a Mac. The only downside with this solution is that Mac users will see an empty disk on their desktop. We decided we could live with that for now.

Also, we found two shortcuts for the Mac version that are worth mentioning. For the PC version we’ve included Firefox Portable, as we’d really hate for anybody to have to use IE when there are alternatives. But on the Mac we let people just use their default browser (IE 5 really isn’t a threat anymore, and the site looks great in Safari) so didn’t need to include one on the stick. Secondly, on the PC we included a light PDF viewer called Sumatra because Adobe tends to take forever to load. The Mac operating system comes with a nice light PDF viewer so we didn’t need to include this in the Mac version.

In a few days, Earnest will write about some of the research that went into this decision and how our initial plan to use Resin didn’t work out once it was on the stick.