The advantage is not that huge if you compare to the author's previous setup, which was based on Ansible. Unless you like to run a different OS per virtual mach

The advantage is not that huge if you compare to the author's previous setup, which was based on Ansible. Unless you like to run a different OS per virtual machine, moving your websites to a new machine (or add a new machine to the bunch) is as easy as with Docker, and you can test your setup locally too (though you will need a VM running on your computer). The biggest advantage of Docker in my opinion is that it makes it much easier to make conflicting software coexist on the same machine (for example two websites requiring two different versions of node.js or php). Also it is nice that you can build the image once and then deploy it many times. Ansible's equivalent is of rebuilding the image every time you want to deploy it. Also I find it a bit easier to accomplish what I want with a Dockerfile than with an Ansible script and if you make some mistakes it is easier to rebuild an image than "cleanup" a VM instance. So, Docker smooths many edges compared to Ansible, but I wouldn't consider that a _huge_ advantage, expecially in the context of a personal infrastructure.