Docker is convenient. You can just download the docker binary and type "docker run postgres" and have a container running Postgres. What's the equivalent for FreeBSD jails?
There is no equivalent of course. I guess people are confused on what jails are. Jails, Solaris Zones, lxc, runC, chroot with namespaces and cgroups are all similar technology that are not solving the same problems as Docker. Docker just uses containers underneath to address specific package management problems. Projects that try to do the same are actually just package managers, like nix and guix.
First command installs the database, second one populates database files, this one starts the database, last command is optional and it creates a database for your user name.
Docker is a turn key solution to three different problems (build, package, run). A lot of people know of alternatives that cover only the run part and then they wonder why their particular solution didn't become as popular.
