Deploying a cobalt site from a git hook

Since I've not have written a blog article in ages, and also not upgrades the static site generator I use, cobalt, I thought I'd hit kill birds with a one-and-a-half stones by documenting my rather minimalist setup and deploying a new version of cobalt. The following parts are involved:

• A bare git repository on my VPS that I can push to via SSH.
• A git post-update git hook in the repository, which is responsible for rendering the repository contents via cobalt.

The post-update hook just calls out to a script that does the actual work, providing it with the "stage directory" and the symlink that is set to the rendered output. The idea here switch the symlink between a "left" and "right" directory, and only switch when the rendering succeeded. This means a push to the git repository will only go live when rendering was successful, adding a bit of a safety net.

Here is the hook itself, where the "left" and "right" directory will be created under /srv/www/example.org/deploy/stage and the symlink pointing to one of those written to /srv/www/example.org/deploy/htdocs. You'll want to point your webserver to that symlink.

#!/bin/sh

PATH="$HOME/bin:/usr/local/bin:/usr/bin:/bin"
export PATH

exec cobalt-git-deploy /srv/www/example.org/deploy/stage /srv/www/example.org/deploy/htdocs

The cobalt-git-deploy script (download) is specific to cobalt, but should be adaptable, with minimal changes, to any other static site generator.