We recently moved from dedicated to cloud servers, so we have a Chef recipe that we run using a knife command to target all web servers in parallel. The recipe

We recently moved from dedicated to cloud servers, so we have a Chef recipe that we run using a knife command to target all web servers in parallel. The recipe looks at each of our git repos, finds ones that have been updated on the appropriate production branch, reclones them, then symlinks them into place, replacing the existing symlink to the old version. As a bonus, the deployment recipe also makes sure all permissions and symlinks are correct. It works pretty well so far; we'll almost certainly be looking at ways to make it easier as it's currently a rather lengthy knife command.