I have a Mysql server running on the host using default port 3306. I Want to run a MySQL docker container using network host but with a different port.
My configuration is defined in a docker-compose file. After building the image and tried running the container, it starts and shutdown with port conflict notice.
Is there a way to dynamically change the container port before starting up? I don’t want to use the network bridge.
Answer
If using host networking is a hard requirement, then nothing in Docker space will be able to control or limit what ports the service does or doesn’t use. You need to change a service-specific configuration file, environment variable, or command-line argument to make it listen somewhere else.
Particularly for servers that listen on a single TCP port (like most database and HTTP-based servers) the default Docker bridge/NAT setup should work fine; alternate setups like host networking and macvlan are unnecessary. If you’re willing to use the standard setup, this is trivial:
version: '3'
services:
mysql:
image: mysql
ports: ['9999:3306'] # listen on host port 9999 instead