dksnap
(https://github.com/kelda/dksnap) automates the process of running pg_dumpall
and loading the dump via /docker-entrypoint-initdb.d
.
It shows you a list of running containers, and you pick which one you want to backup. The resulting artifact is a regular Docker image, so you can then docker run
it, or share it by pushing it to a Docker registry.
(disclaimer: I'm a maintainer on the project)