# Isolated CPUs Device Plugin for Kubernetes

## About

This code implements a Kubernetes device plugin.  The plugin detects all CPUs
specified via "isolcpus=X" in the kernel boot args, and exports them to
Kubernetes as custom devices using the deviceplugin API.

It makes heavy use of the Intel device plugin manager from github.com/intel/intel-device-plugins-for-kubernetes
and credit is due to them for making a useful helper.  A good example of how
to use that framework can be found at
https://github.com/intel/intel-device-plugins-for-kubernetes/blob/master/cmd/gpu_plugin/gpu_plugin.go



## Implementation Notes

There are currently problems with using go modules for the deviceplugin API...it
leads to an "go: error loading module requirements" error when running "go build".
Accordingly, it was necessary to copy a number of files from external packages.
As part of this work I also updated the deviceplugin API files to the latest
versions to pick up in-development upstream changes.


The "intel/intel-device-plugins-for-kubernetes" subdirectory corresponds to
"github.com/intel/intel-device-plugins-for-kubernetes".

The "kubernetes" subdirectory corresponds to "k8s.io/kubernetes"

In an ideal world, these two subdirectories would not be needed, and instead we
would simply include the following imports in isolcpu.go:

	"github.com/intel/intel-device-plugins-for-kubernetes/pkg/debug"
	dpapi "github.com/intel/intel-device-plugins-for-kubernetes/pkg/deviceplugin"
	pluginapi "k8s.io/kubernetes/pkg/kubelet/apis/deviceplugin/v1beta1"
	"k8s.io/kubernetes/pkg/kubelet/cm/cpuset"

This would also require updating the Intel package to pick up the latest
deviceplugin API so that the topology field is properly represented.

## Build Notes
In order to avoid the need for a network connection to download dependencies
at build time, I've chosen to include all the dependencies in the "vendor"
directory.  This is auto-generated by running "go mod vendor".  The binary
is then built with "go build -mod=vendor".