Docker vs. Shared windows folders

Question

I'm trying to access a remotely shared folder from within a docker container on Docker for Windows.

While inside the container running dir \target\share produces "The network path was not found.". The target can be pinged from inside the container and from the host system the share is accessible.

The image used is microsoft/dotnet-framework:4.7.2-sdk and I'm running it with just the -it option for testing.

What am I missing to get this to work?

user_4227687 · Answer

The SMB protocol works with hosts in the same LAN. A docker container, by default, has a virtual network interface behind a NAT, so the container is no longer in the same LAN. This is why you can ping the target, but you can't access the shared folder.

The easier solution is to add the option --network host to the docker run command. In this way the container has access to the same network interfaces as the host and no virtual interface is created.

user_3086836 · Answer

You can use docker volumes to mount a folder/network share in the container

Create docker volume on the host:

$ docker volume create --driver local \
    --opt type=nfs \
    --opt o=addr=192.168.1.1,rw \
    --opt device=:/path/to/dir \
    foo

Mount the volume on container:

$ docker run -d \
  --name devtest \
  --mount source=foo,target=/app \
  nginx:latest

More examples here

Docker vs. Shared windows folders

2 Answers