Map running container port to the Host
We recently ran to a situation that we have a running container (MySQL) but we liked to access it from internet and this container didn't have any port mapping between host and container.
We spawn up the container with docker compose
One solution for this situation is to stop the container, remove it and execute docker run with
-p <hostPort>:<containerPort> but we didn't want to create new container.
Second solution is using
iptables to do the port mapping.
In the following example, you see how we achieved routing calls to the
host:3306 to the
You should run this on the host machine.
sudo iptables -t nat -A DOCKER -p tcp --dport 3306 -j DNAT --to-destination MysqlContainerIP:3306 sudo iptables -t nat -A POSTROUTING -j MASQUERADE -p tcp --source MysqlContainerIP --destination MysqlContainerIP --dport 3306 sudo iptables -A DOCKER -j ACCEPT -p tcp --destination MysqlContainerIP --dport 3306