usb-modules

A docker image to build and install the usbip kernel module (and friends). Some standard kernels (looking at you, Azure kernel) do not include USB kernel modules. While, yes, you can install the generic mainline kernel... there's downsides to that...

Currently, this repo provides the following modules:

• ghcr.io/silvenga-docker/usb-modules/usbip:
  • usbip-core
  • vhci-hcd
• ghcr.io/silvenga-docker/usb-modules/serial:
  • usbserial
  • usb-serial-simple
  • ftdi_sio

Setup

docker run -it --rm \
    -v /usr/src:/usr/src:ro \
    -v /lib/modules:/lib/modules:ro \
    --privileged \
    ghcr.io/silvenga-docker/usb-modules/usbip:master

The following paths must be mounted from the host (to build against the correct symbols).

Host Path	Container Path	Access	Why?
/lib/modules	/lib/modules	Read-only	To build modules, the original kernel build parameters are needed. This includes symbols so that built-module can use kernel functions. In the future (hopefully) this will also allow the container to noop if the module is already loaded, or was included with the distribution.
/usr/src	/usr/src	Read-only	The modules directory actually symlinks to /usr/src.
	/build	Read/Write	To allow the usage of read-only containers the well-known /build directory is used. Consider this cache space, the contents are ignored after restarts.

Note that --privileged must be set to allow the container to install the kernel module.

Theory

The idea behind this docker image is to provide K8s environments the ability to access USB devices exposed using usbipd to a cluster. My theoretical plan is to:

• On container image start, build the module based on the mounted kernel source.
• modprobe the built module.
• On capturing a term signal, unload the module.

Might also be a good idea to allow kernel modules to be mounted, so the container could load existing modules if included.