The meeting day voting application (vote often!) that we’ve been mentioning everywhere all week is a new departure for mySociety. In a frantic bid to catch up with the cool kids, it’s our first deployed Ruby on Rails application. This happened because Louise Crow, who kindly volunteered to make it (thanks Louise!), felt like learning Rails. We used to have a policy of using any language, as long as it was open source and began with the letter P (Python/Perl/PHP…). This has now been extended to the letter R!
You can browse the source code in our CVS repository. One interesting thing about Rails applications is that they are structured things, a deployable directory tree. So are mySociety applications.
For example, take a look at PledgeBank’s directory. It’s a mini, well defined filesystem – the ‘web’ directory is the meat of the stuff, but note also ‘web-admin’ for the administrator tools. Include files are tucked away in ‘perllib’ and ‘phplib’, while script files nestle under ‘bin’. We keep configuration files (analogous to the Windows Registry, or /etc on Unix) under ‘conf’. Database schema files live in ‘db’.
And a rails application is much the same. But much much much more detailed. Some of those are extra directories which we also have, but only when we deploy, not in CVS (for example, log files). All in all they are surprisingly similar structures, which shows we’re either both on the right lines, or both on the wrong false trail.
Like making Frankenstein’s monster, poor Louise and I had to graft these two beasts together just to deploy this small application. For example, we have a standard configuration file format which we read from Perl, Python and PHP. The deploy system does useful things with it like check all entries are present, and generate the file for any sandbox from a template. To get round this, there’s an evil script, possibly the first time PHP has been used to make YAML. (And please don’t look at the thing that makes symlinks.)
We could have extended Rails to be able to read its configuration from our file format, but that would be a lot more work. And we could have discovered how to hack its log file system to write to the mySociety log file directory. But everything is so coupled, it doesn’t ever seem worth it. Any Rails apps we deploy will just have to be an even more confusing mass of directories, application trees inside application trees.