maintaining Drupal sites using version control

Subversion is a great tool, we made the switch to using it a few years ago and wonder how we survived previously.

I listened to the Lullabot podcast as well for reference and it describes our basic process as well. I happen to develop on a Windows platform (sigh), and use XAMPP (www.apachefriends.org/en/xampp.html for apache, mysql, php) and Tortoise SVN (http://tortoisesvn.tigris.org/ a nice GUI interface on SVN).

This helps us keep our house in order and is extremely useful. One other tool we've added to the mix is sitecopy (www.lyra.org/sitecopy/) and a little script that helps us deploy the most recent, stable version of our code. Sitecopy itself is a bit dated, but works fine - you could swap it for a number of other tools (like rsync, for example).

The basic process, however, is that we keep a development server with our combined updates and when we feel that the code is ready for deployment, we run an update command (a small shell script) which uses sitecopy to push the files to the staging server as well as to add a subversion deployment flag (saying that version so-and-so of the files was pushed to the stage server on thus-and-such-date-and-time). If all tests well on the stage, we repeat the command, but this time to the live server. If we ever have problems, we can roll back to the previously released code (using subversion) and push that.

In this way, we use the benefits of subversion to manage our development process as well as the code that gets deployed to the live site.

So - yes - SVN is great, and any version control at all is a wonderful improvement from none.

Drew Gorton
_{Gorton Studios}

SVN (or other revision control systems) are really useful for maintaining sets of files and data similar to a filesystem. It's easy to do rapid deployment of your work across many locations with it, and it's also useful to keep track of what you've been doing (and rolling back to a better version, should you need that). here's another developer talking about how he uses SVN for web site maintenance.

However, with projects like drupal, where much of the configuration and deployment is done via a web interface, it's much more difficult to get a smooth rollout. For example: consider adding a new module. You can add the module to a local working directory (on a development web server), and test it to make sure it works. Then (after committing it to your SVN repository) you can roll it out to a staging server to make sure that you've got the deployment technique right. If that works, you roll it out to your live server.

But at each step along the way, after deploying the files via SVN, there are a series of additional steps that need to be taken, usually via the web interface. You have to enable the module, then you have to choose how to configure its access permissions, etc.

I haven't found a way yet to get a revision control system to easily handle these sorts of db changes, which means that these steps have to be done by hand at each step of the deployment process. This is both tedious and error-prone. And even worse, there's no clean way to roll back the db changes necessarily, should you make a mistake or later decide that you made a bad decision.

If drupal had a clean way to script interactions with its UI, it would be another matter: you could just write the things you wanted to do into a script, and after the svn update (which you've already tested elsewhere), run the script.

If someone knows of a project to create such a scriptable interaction, i'd be curious to hear about it. It would make public deployments much less nerve-wracking.