Apache 2.4 with mod_lua

Moonrise

Article from ADMIN 09/2012

By Tim Schürmann

Lua is a small, lean, and fast scripting language – ideal for working with web servers. Version 2.4 of the Apache web server is the first to offer a matching module that has a few quirks – and pitfalls, if you dig more deeply.

The Lua scripting language was developed in 1993 at the University of Rio de Janeiro and was placed under the MIT license as of version 5 [1]. The interpreter, which weighs in at just a few kilobytes, is seriously fast and can use a C interface to dock with other programs. This has made Lua very popular in the gaming industry in particular. But Lua has slowly made inroads into more serious applications, such as Adobe's Lightroom or Wireshark. Lua itself is an imperative and functional language, with rudimentary support for object-oriented programming. The syntax uses a minimum of keywords, which – on the downside – makes Lua programs more cryptic than their PHP counterparts.

Damp Squib

Thanks to all these properties, Lua would seem to be an obvious choice of scripting language for web servers. Thus, it is no surprise that modules for Apache have been presented at various phases of the language's history. The ambitious Kepler project took this one step further [2], introducing a number of self-developed tools, libraries, and standards that aimed to give developers the ability to produce complete web applications simply in Lua. One of the results was Xavante [3], a web server written in Lua. The Kepler project has been dormant since 2010; the many Apache modules never made the cut for the official Apache package and thus quickly disappeared from sight – with one exception.

In 2006, Brian McCallister started work on a module with the slightly wacky name of mod_wombat. It welds the Lua interpreter onto the Apache web server, which lets the server launch and execute Lua scripts – very much in the style of mod_php and mod_perl. Although development was slow over the years, McCallister's

...

Use Express-Checkout link below to read the full article (PDF).