Build containers inside one network instead of using --link

Hi,

I recently run into an issue when running build using gitlab runner with docker images. I want to test my web app (one container) with selenium (second container). The problem is that the selenium container is a service and it does not know the IP of the main (web) container.

The solution is very simple - create a network

docker network create CI_BUILD_ID

And then run a simple command for each container:

docker network connect CI_BUILD_ID CONTAINER_ID

It can be also achieved by adding a network and then adding --net=NETWORK_ID to docker run commands.

After all build containers are in the same network - they can see each other.