SocketCAN/vcan support in Ubuntu VM

[appelgriebsch]

Hey, following the discussion here docker/for-mac#4405 I'm looking for a way to use SocketCAN within my colima VM, but it seems the required kernel modules are not available as well....

Can I use a custom-tailored VM instead, or are there any plans to introduce them into the default image?

[abiosoft]

Can I use a custom-tailored VM instead

Not yet, except you build Colima from source. Ability to specify custom images is being considered.

or are there any plans to introduce them into the default image?

No objections actually, I only need the instructions on how to do that.
And feel free to contribute if you have the skillset for that, the Ubuntu image is being customized in this script https://github.com/abiosoft/colima-core/blob/main/scripts/qcow.sh

[abiosoft]

Is it reproducible: Yes. Take an Alpine/Debian/Ubuntu docker image, install can-utils (with a package manager or by compiling from source)

If that's all required, you can simply ssh into the Colima VM and install that.

# install can-utils
colima ssh -- sh -c "sudo apt update && sudo apt install can-utils"

# restart (if required)
colima restart

If that works for you as desired, then I can include the package in the default image going forward.

[appelgriebsch]

Sadly it's not. It requires availability of certain kernel modules (namely vcan) to be able to create virtual vcan network interfaces. Just checked the build script. As it's using the ubuntu-minimal cloud image I can imagine those kernel modules are not configured at all.... which either means: using a different (larger) base image, or compiling certain kernel modules on your own.... (which makes updating to newer images quite complex)

[appelgriebsch]

According to the ticket in docker-for-mac the following minimum set on kernel modules need to be configured

#
# CAN Bus support
#

CONFIG_CAN=m
CONFIG_CAN_RAW=m
CONFIG_CAN_BCM=m
CONFIG_CAN_GW=m

#
# CAN Device Drivers
#
CONFIG_CAN_VCAN=m
CONFIG_CAN_DEV=m