Consider providing a CDI spec file for USB-based cameras (Docker/containers) #115
Description
tl;dr: it would be greatly appreciated if Zivid could make a CDI (Container Device Interface) spec available for USB-based Zivid cameras to facilitate passing them through to containers.
original: for a project in which we use a Zivid One Plus M, we're trying to host the ROS driver (and required/related Zivid SDK) in a Docker container.
The camera is a USB device and actually enumerates quite a few devices, all of which seem to have to be available for the driver/SDK to work correctly (if we understand things correctly). The typical approach with Docker would be to pass device nodes to containers using --device (or sometimes as bind-mounts of actual device nodes).
As it's not completely clear which devices belong to the Zivid camera, we're currently passing /dev itself to the container. While this works, it's not very nice, as it pokes a big hole in the isolation typically offered by containers. It's also not always possible, either due to security concerns or other logistical barriers.
The container community has come up with a specification (CDI, the Container Device Interface) which allows to succinctly describe what resources would need to be made available to a container in order to "mount a device" and be able to use it from within that container. As a good example, NVIDIA supports CDI for its various GPUs and accelerators as they are/can be quite complex devices to properly expose to a container.
One of the main motivators for the creation of CDI seems to describe the characteristics of USB-based Zivid cameras well (emphasis mine):
On Linux, enabling a container to be device aware used to be as simple as exposing a device node in that container. However, as devices and software grows more complex, vendors want to perform more operations, such as:
- Exposing a device to a container can require exposing more than one device node, mounting files from the runtime namespace, or hiding procfs entries.
- [..]
Instead of reverse-engineering all the required devices and resources ourselves, I'm wondering whether Zivid would consider providing a CDI spec for their USB-based devices. It should make use of these devices in containers (not just Docker, but also Podman fi) quite a bit more straightforward.
If that would not be possible, some guidance on which devices are enumerated after connection of a Zivid One Plus M to a Linux-based OS would be appreciated. The community could then potentially come up with a CDI spec itself.