Add a volume to Docker, but exclude a sub-folder

Question

Supposed I have a Docker container and a folder on my host /hostFolder. Now if I want to add this folder to the Docker container as a volume, then I can do this either by using ADD in the Dockerfile or mounting it as a volume.

So far, so good.

Now /hostFolder contains a sub-folder, /hostFolder/subFolder.

I want to mount /hostFolder into the Docker container (whether as read-write or read-only does not matter, works both for me), but I do NOT want to have it included /hostFolder/subFolder. I want to exclude this, and I also want the Docker container be able to make changes to this sub-folder, without the consequence of having it changed on the host as well.

Is this possible? If so, how?

Answer 1

Using docker-compose I'm able to use node_modules locally, but ignore it in the docker container using the following syntax in the docker-compose.yml

volumes:    - './angularApp:/opt/app'    - /opt/app/node_modules/ 

So everything in ./angularApp is mapped to /opt/app and then I create another mount volume /opt/app/node_modules/ which is now empty directory - even if in my local machine ./angularApp/node_modules is not empty.

Answer 2

If you want to have subdirectories ignored by docker-compose but persistent, you can do the following in docker-compose.yml:

volumes:   node_modules: services:   server:     volumes:       - .:/app       - node_modules:/app/node_modules 

This will mount your current directory as a shared volume, but mount a persistent docker volume in place of your local node_modules directory. This is similar to the answer by @kernix, but this will allow node_modules to persist between docker-compose up runs, which is likely the desired behavior.