Unable to mount dir in / of host

Expected behavior

When running:
docker run -it -v /builds:/builds centos:7.2.1511 bash

My Mac’s /builds directory should be accessible via the resulting container. /builds has the same ownership and permission of my home directory, which DOES mount.

Actual behavior

/builds is mounted using tmpfs filesystem.

[root@c2e042a3953e /]# df -h
Filesystem Size Used Avail Use% Mounted on
none 60G 747M 56G 2% /
tmpfs 1001M 0 1001M 0% /dev
tmpfs 1001M 0 1001M 0% /sys/fs/cgroup
tmpfs 1001M 175M 826M 18% /builds
/dev/vda2 60G 747M 56G 2% /etc/hosts
shm 64M 0 64M 0% /dev/shm

Steps to reproduce the behavior

Already decribed.


I’m seeing the same. It seems it is only possible to mount directories within the home dir on the host machine. Tried many different permissions/ownership settings.


Currently (Beta 16), Docker for Mac has a fixed set of exported directories which are placed into the bind mount -v namespace. These paths are /Users, /Volumes, /private, and /tmp. To access other paths, during the Beta only, you can prefix the path with /Mac. For example, to mount /builds into a container, use -v /Mac/builds:/builds. See https://docs.docker.com/docker-for-mac/osxfs/#namespaces for more information. Configurable export path support will be released soon.

Thanks for participating in the Docker for Mac Beta!

Great, thanks. Keep up the fantastic work!