Web technologies for an embedded server

Question

I've recently started a new web development project for an embedded device and wanted to solicit some recommendations for technologies to use. The device will serve HTML pages which include AJAX code to retrieve data from a JSON server. We're tentatively using Cherokee as the web server, though we're not tied to it.

Currently, I'm considering the following technologies:

• Write it all in PHP. I know it's big, slow, and bloated, but I've got about 10MB available for the web interface (a lot for an embedded system), and we won't be seeing a lot of traffic on any of these devices. It does need to seem responsive for the users, however (pages should load in less than a second).

• FastCGI + a C program - We're using an in-memory database, so the C program could interact with the database directly through the API. This would have much better performance than PHP, but development time and reliability is a concern since C isn't very well-suited for web development.

• Lua + Kepler - This seems like a nice middle ground between performance and development time. However, I've never worked with Lua, so I'm not really sure how to implement it in an embedded web project. I'm also uncertain as to how well it integrates with the Cherokee web server.

So any opinions or past experiences with the above stated technologies? Any others I should include in the list?

Thanks, Alex

Answer 1

When I was in this area, I used Lua and a simple FastCGI runner (Luaetta [for I'm sure the latest source would be available if you asked the guy] , though I'm also sure that's not the only one, and there's Kepler of course), spawned by lighttpd.

It performed quite well on an embedded media player, and was used for remotely accessing content and controlling the device. Though I don't maintain it anymore, you can find more about it at http://matthewwild.co.uk/projects/wooble . If you think the source would help just poke me for it, it's currently only available via a package manager but I can fix that given the motivation.

Another (again Lua) project in this area is LuCI. These guys are dedicated to making a web interface for embedded devices (routers specifically), and have produced a nice framework with lots of supporting libraries geared towards that kind of system.

I wouldn't be concerned with not knowing Lua. If you know any language then you can pick up Lua in a day or two, the manual documents the whole language and is quite short.