I've been working on CLI that builds and pushes a bunch of docker images at once.
By default, it searches recursively in your current directory for directories containing a Dockerfile
It uses buildkit, the new docker backend for "docker build", which means that it dedupes multistage build steps across the images, and builds very fast.
For example, you can define an environment with a registry, then "sanic build -t mytag –push" to build and push everything in parallel.
It's open source! https://github.com/distributed-containers-inc/sanic