host.docker.internal



+300
Edit:

If you are using Docker-for-mac or Docker-for-Windows 18.03+, just connect to your
mysql service using the host host.docker.internal 
(instead of the 127.0.0.1 in your connection string).

If you are using Docker-for-Linux 20.10.0+, you can also
use the host host.docker.internal if you started your Docker container with 
the --add-host host.docker.internal:host-gateway option.

Otherwise, read below