Today, I migrated all my domains to the new server. While at it, I set up a mirror of my blog repository at http://git.plenz.com/blog/. You could view the pure markdown files there, or see how I messed around with Jekyll stuff.
The sync is called from a post-receive hook with the command:
env GIT_SSH=`pwd`/hooks/blogpush git push -f git@git.plenz.com:blog master
... where blogpush is just a little wrapper to make SSH use the
public key that has access to the repository:
#!/bin/sh
ssh -o ControlMaster=no -i /home/feh/blog.git/hooks/fehblog $@