Implement file sharing

[cfergeau]

We need a way to share files/directories with the crc VM. The first use case would be for the podman preset, to implement podman-remote -v localdir:remotedir. There are several options:

• virtiofs
• sshfs

[cfergeau]

The way podman does it is by mounting (on a mac) /Users/teuf to /Users/teuf inside its VM using 9p. Then podman-remote -v /Users/teuf/localdir:remotedir can be used successfully.

I've added virtiofs support to vfkit in https://github.com/cfergeau/vfkit/tree/virtiofs , though this depends on an unmerged PR in Code-Hex/vz

This is then used by https://github.com/cfergeau/crc/commits/macos-vf (various paths/tags are hardcoded at the moment).

With these changes, I can start a VM using the podman bundle, and /Users/teuf is mounted to the same path in the VM. /Users/teuf in the VM is owned by core.core even if the host/VM UIDs are different. However, podman -v /Users/teuf/localdir:remotedir fails:

# ls /foo/
ls: cannot open directory '/foo/': Permission denied

This happens both with rootless and rootful podman.

EDIT: After running setenforce 0 in the VM, this works fine!!

macOS ~ % mkdir podman-test
macOS ~ % touch podman-test/hello-world
macOS ~ % ~/.crc/bin/oc/podman run -v /Users/teuf/podman-test:/foo -it --rm docker.io/redhat/ubi8

[root@e43226ed1836 /]# ls /foo/
hello-world
[root@e43226ed1836 /]# touch /foo/hello-from-container
[root@e43226ed1836 /]# exit

macOS ~ % ls ~/podman-test 
hello-from-container	hello-world

EDIT2: adding context="system_u:object_r:container_file_t:s0" to the virtiofs mount options allow to use this even with selinux set to enforcing mode.

[cfergeau]

podman-machine has a trick to access /Users/teuf. Through 9p, /Users/teuf is owned by a user with the same uid as I have on my mac. When podman-machine creates its VM, its ignition file creates a core user with the same uid as the one teuf has locally on the mac. This eases some of the permissions/ownership issues that might occur.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[anjannath]

closing this more updates in the epic