How to forward a file to a container inside a container?

Question

Docker

Colleagues, help to understand!
The question appeared while running gitlab-runner in a container. When I started to figure it out, the problem turned out to be in docker itself. The bottom line is this:
I launch a docker container, forward /var/run/docker.sock into it (this is necessary for docker to work inside the container with gitlab-runner) and a file from the /123 directory (the directory will be /456 inside the container). Next, inside the container, I launch another one (for example, nginx:latest), into which I also transfer the file from the /456 directory (the directory will be /789 inside the nginx container). In the last nginx container, a directory with the name of the file appears instead of a file.
What could be the problem?

Answer 1

https://docs.docker.com/storage/volumes/ https: //dotsandbrackets.com/persistent-data-docker
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