CODEWITHSUNDEEP
dockerlinux-device-driverubuntu-18.04ubuntu-20.04usbserial
Pyy
Pyy

Reputation: 367

How to install linux-modules-extra?

When I run sudo apt install linux-modules-extra-$(uname -r) in a Docker container based on a Ubuntu 20.04 on a single board computer running Ubuntu 18.04, I get the following errors:

E: Unable to locate package linux-modules-extra-4.15.0-143-generic
E: Couldn't find any package by glob 'linux-modules-extra-4.15.0-143-generic'
E: Couldn't find any package by regex 'linux-modules-extra-4.15.0-143-generic'

To me, this makes me wonder whether it is even possible to install linux-modules-extra-4.15.0-143-generic in Ubuntu 20.04? Maybe it is only compatible with Ubuntu 18.04?

Could anyone clarify this for me please?

Upvotes: 2

Views: 16804

Answers (1)

David Maze
David Maze

Reputation: 159352

In general, if you're building a kernel module, it has to match exactly the kernel that's running on the host system. If you're using a native Debian or Ubuntu system (without Docker), there's a system where kernel modules can be rebuilt or reinstalled when the host kernel is updated. See for example the Debian wiki KernelDKMS page.

In contrast, a Docker image is generally supposed to be portable across hosts. If you upgrade the host's kernel, or if you run a FROM ubuntu:18.04 image on an Ubuntu 20.04 host, the image isn't really supposed to be aware of this.

In your particular case, you can't get the kernel headers you need, because they're not part of the Ubuntu 18.04 distribution. For this particular case it might be possible to get the headers from the later version of Ubuntu, but it might not be possible in the general case; maybe because the system is actually running plain Debian or RHEL and the kernel build is different, maybe because the operator built their own kernel.

Since a Linux kernel module is so specific to the host it runs on, and since it can bypass any and all security concerns, it's not appropriate to try to install one in a container. Do it directly on the host instead.

Upvotes: 5

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