Issues with Docker Daemon when user namespace is enabled

[lawliet89]

When the Docker daemon has user namespace enabled, the following will fail

• Reading/writing to bind mount volumes
• --privileged flag

The fix is as simple as adding --userns=host to the docker command. BUT this will break on older Docker client versions that do not support this. I can probably fix this easily, but I am not sure how I should proceed.

EDIT: I suggest this: Use a lazy_static or something similar to do a docker engine version check. (docker version --format '{{.Server.APIVersion}}') Then if the semver is newer than 1.24, we automatically add the flag --userns=host.