I'm rewriting the problem, to put more details.
I set up a jss app in a docker container. It's working fine, even the Experience Editor has already been put to work in this environment.
It turns out that the communication between the jss app container and the CM container is communicating smoothly with the hostname (http://cm). However, when I get it from my browser, it comes with http://cm in the image url, as the GraphQL call is made between the jss app container (nodejs) and the CM container (sitecore). As what comes in the url of the image is http://cm, I can't get it from my computer's browser, because to call the traefic it should be https://cm.maverick-docker.localhost
How to make the sitecore return the images with the public url of the CM, not with the internal url?