[harveynick]

I think this is what you're looking for: https://github.com/TryGhost/Ghost-CLI

I've only used it for a local install when playing with my site theme, but it worked great (albeit quite picky about the versions of the dependencies).

[bluehatbrit]

When they launched ghost cli with ghost 1.0 I moved over to it a few days after it had launched (small blog, not much readership). It was really easy to move over to it, and updating ghost is a single command. I update it every time there's a feature I want or once every few months. It's not without its issues, but they're being actively worked on and it's improving each time I update the cli as well. I'd recommend it to anyone self hosting a single instance blog.