Installing Kernel Modules that require Kernel Headers


To compile any kernel modules, you will need to download the kernel headers. The kernel headers are available in the form of a system service. Since the kernel headers are a system service, they need to be enabled using the ros service command.

Installing Kernel Headers

The following commands can be used to install kernel headers for usage by containers in Docker or System Docker.

Docker

$ sudo ros service enable kernel-headers
$ sudo ros service up kernel-headers

System Docker

$ sudo ros service enable kernel-headers-system-docker
$ sudo ros service up kernel-headers-system-docker

The ros service commands will install the kernel headers in /lib/modules/$(uname -r)/build. Based on which service you install, the kernel headers will be available to containers, in Docker or System Docker, by bind mounting specific volumes. For any containers that compile a kernel module, the Docker command will need to bind mount in /usr/src and /lib/modules.

Note: Since both commands install kernel headers in the same location, the only reason for different services is due to the fact that the storage places for System Docker and Docker are different. Either one or both kernel headers can be installed in the same RancherOS services.

Example of Launching Containers to use Kernel Headers

# Run a container in Docker and bind mount specific directories
$ docker run -it -v /usr/src:/usr/src -v /lib/modules:/lib/modules ubuntu:15.10
# Run a container in System Docker and bind mount specific directories
$ sudo system-docker run -it -v /usr/src:/usr/src -v /lib/modules:/lib/modules ubuntu:15.10