Volumes mounted in a container which are inside a folder which is also a volume mount no longer have their content in the container. See the reproduction steps below for an example.

Steps to reproduce the behavior

Test Project Structure

• inner/
  • inner-file.txt (empty dummy file)
• outer/
  • outer-file.txt (empty dummy file)
• docker-compose.yml (see content)

docker-compose.yml

version: "3.7"
services:
  centos:
    container_name: nested_mount_test
    image: centos
    command: sleep 10m
    volumes:
      - ./outer:/test
      - ./inner:/test/inner

1. In the folder with docker-compose.yml file, run docker-compose up –d
2. Run docker exec -it nested_mount_test /bin/bash
3. Run cd /test and verify that there is a file called outer-file.txt and a folder called inner inside /test
4. Observe the content of /test/inner

Expected behavior

When observing the content of /test/inner, it should container inner-file.txt

Actual behavior

When observing the content of /test/inner, it is empty

Information

In Docker Desktop 2.1.0.4, this works as expected, but after upgrading to Docker Desktop 2.2.0.0, the volume mounted inside another volume has no content.

• Windows Version: Windows 10 Version 1809
• Docker Desktop Version: 2.2.0.0
• Are you running inside a virtualized Windows e.g. on a cloud server or on a mac VM: No