# Assignment - Device Plugin
###### tags: `Assignment`, `Device Plugin`

## Outline

You should read the [Nvidia Device Plugin](https://github.com/NVIDIA/k8s-device-plugin) & trace code

:::info
Version: nvidia/k8s-device-plugin:v0.7.0-rc.7-ubuntu16.04
:::

## Problem Description

目標： 將目前node上的gpu個數虛擬成兩倍
假設現在`nvidia.com/gpu = 2`，請透過修改source code的方式將其變為`nvidia.com/gpu = 4`

確認正常運行

$  kubectl logs -n kube-system ${POD_NAME}


並且請使用你修改好的device plugin測試

$ kubectl apply -f pod2.yml

apiVersion: v1
kind: Pod
metadata:
  name: pod1
spec:
  restartPolicy: OnFailure
  containers:
  - image: nvidia/cuda
    name: pod1-ctr
    command: ["sleep"]
    args: ["100000"]

    resources:
      limits:
        nvidia.com/gpu: 1
---
apiVersion: v1
kind: Pod
metadata:
  name: pod2
spec:
  restartPolicy: OnFailure
  containers:
  - image: nvidia/cuda
    name: pod1-ctr
    command: ["sleep"]
    args: ["100000"]

    resources:
      limits:
        nvidia.com/gpu: 1
---
apiVersion: v1
kind: Pod
metadata:
  name: pod3
spec:
  restartPolicy: OnFailure
  containers:
  - image: nvidia/cuda
    name: pod1-ctr
    command: ["sleep"]
    args: ["100000"]

    resources:
      limits:
        nvidia.com/gpu: 1
---
apiVersion: v1
kind: Pod
metadata:
  name: pod4
spec:
  restartPolicy: OnFailure
  containers:
  - image: nvidia/cuda
    name: pod1-ctr
    command: ["sleep"]
    args: ["100000"]

    resources:
      limits:
        nvidia.com/gpu: 1


$ kubectl apply -f pod2.yaml

apiVersion: v1
kind: Pod
metadata:
  name: podtwo
spec:
  restartPolicy: OnFailure
  containers:
  - image: nvidia/cuda
    name: pod1-ctr
    command: ["sleep"]
    args: ["100000"]

    resources:
      limits:
        nvidia.com/gpu: 2


## Reference
+ Device Manager Proposal
https://github.com/kubernetes/community/blob/master/contributors/design-proposals/resource-management/device-plugin.md
+ Kubernetes如何通過Device Plugins来使用NVIDIA GPU
https://my.oschina.net/jxcdwangtao/blog/1793656
+ NVIDIA/k8s-device-plugin源碼分析
https://www.twblogs.net/a/5c03de34bd9eee728baac89b