Intro

Docker container to automatically mount linux devices (mass storage devices attached via usb) to subfolders in a specified parent folder, bound as a volume. Intended for use on a DIY NAS running Rockstor, which is missing this capability but probably works universally.

Functionality

• Initially unmounts all devices that had a subdir in the volume that is bound to /usb
• Automatically mounts devices with filesystem of type {'ntfs', 'exfat', 'xfs', 'vfat', 'ext4', 'ext3', 'ext2', 'fat32', 'fat16'}
• Mounted folder becomes a subdirectory of the parent (see volume) named after its partition-name

Example

If the container runs with e.g. -v "/mnt/external/devices:/usb:rshared", the devices connected to the host via usb would mount under mnt/external/devices. E.g. a usb stick with 4 GB with a partition formatted to exFat would ususally pop up as /dev/sdX, in this example /dev/sdb. The device tree of lsblk would look like this:

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sdb           8:64   0 931.5G  0 disk
└─sdb1        8:65   0    16M  0 part

The container would recognize the new sdX device (here sdb) and mount its partition(s) under /mnt/external/devices/sdb1 and so on, if more than one partition exists, resulting in

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sde           8:64   0 931.5G  0 disk
└─sdb1        8:66   0 931.5G  0 part /mnt/external/devices/sdb1

The partition is now mounted as a folder and can be accessed using shell, UI, FTP, SMB, whatever.

Docker

docker run \
    -d \
    --privileged \
    -e POLLING_INTERVAL=5 \
    -v /dev:/dev \
    -v /parent_folder:/usb:rshared \
    --name doganm95-linux-device-automount \
    ghcr.io/doganm95/linux-device-automount:latest

• Replace /parent_folder with your folder path
• Replace POLLING_INTERVAL with the time in seconds the detection loop should wait between each iteration
• Don't touch /dev:/dev, this is necessary to let the container access the host devices