Working on docker can be time and disk consuming process. I discovered this feature recently, I feel like its really underrated.
DOCKER_HOST flag will use your remote machine where docker is installed as the default host.
I stored the above flag in my shell profile (zsh) and whenever I want to push some code, I update my docker-compose file and simply run respective build and start command and everything is pushed to my remote host automatically and securely using ssh, and without running a single container on my local machine. There's no need for me to have complex github actions and heroku setups etc. It just works!
Its been a real life saver for me, hope someone out there will find it useful as-well.