安裝Scheduler-plugins v1.18

安裝Scheduler-plugins v1.18

創建 Kubernetes 集羣

Kubernetes 版本必須 >= v1.18.0 ，檢查 Kubernetes 版本 kubectl version --short

安裝版本 v0.18.9 並使用 Coscheduling

本節將會說明如何用 scheduler-plugins 鏡像替換默認調度器。 由於新映像是在默認調度器之上構建的，因此會保留原生 Kubernetes 調度功能。同時可以獲得許多額外的開箱即用功能（由此 repo 中的插件實現），例如 coscheduling。

1. 登陸到 Master 節點

   • 如果你的集羣使用 kind 創建

     sudo docker exec -it $(sudo docker ps | grep control-plane | awk '{print $1}') bash
     

   • Mac Docker Desktop

     docker run -it --rm --privileged --pid=host justincormack/nsenter1
     

2. 備份 kube-scheduler.yaml

   cp /etc/kubernetes/manifests/kube-scheduler.yaml /etc/kubernetes/kube-scheduler.yaml
   

3. 創建 /etc/kubernetes/coscheduling-config.yaml

   apiVersion: kubescheduler.config.k8s.io/v1alpha2
   kind: KubeSchedulerConfiguration
   leaderElection:
     # (Optional) Change true to false if you are not running a HA control-plane.
     leaderElect: true
   clientConnection:
     kubeconfig: /etc/kubernetes/scheduler.conf
   profiles:
   - schedulerName: default-scheduler
     plugins:
       queueSort:
         enabled:
         - name: Coscheduling
         disabled:
          - name: "*"
       preFilter:
         enabled:
         - name: Coscheduling
       permit:
         enabled:
         - name: Coscheduling
       unreserve:
         enabled:
         - name: Coscheduling
   

4. 修改 /etc/kubernetes/manifests/kube-scheduler.yaml 使用 Coscheduling 運行調度器插件

   主要修改內容如下所示：

   • 通過參數 --config 傳入 scheduler-config 文件
   • 刪除重複的（已在配置文件中定義） CLI 參數（例如，--leader-elect）
   • 用 scheduler-plugin 鏡像替換默認調度器鏡像
   • 在調度器啓動時掛載 scheduler-config 文件

   --- /etc/kubernetes/kube-scheduler.yaml 2021-02-04 01:27:42.392508733 +0000
   +++ /etc/kubernetes/manifests/kube-scheduler.yaml       2021-02-04 04:26:04.459171135 +0000
   @@ -13,11 +13,12 @@
        - kube-scheduler
        - --authentication-kubeconfig=/etc/kubernetes/scheduler.conf
        - --authorization-kubeconfig=/etc/kubernetes/scheduler.conf
   +    - --config=/etc/kubernetes/coscheduling-config.yaml
        - --bind-address=127.0.0.1
        - --kubeconfig=/etc/kubernetes/scheduler.conf
        - --leader-elect=true
        - --port=0
   -    image: k8s.gcr.io/kube-scheduler:v1.19.1
   +    image: k8s.gcr.io/scheduler-plugins/kube-scheduler:v0.18.9
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 8
   @@ -47,6 +48,9 @@
        - mountPath: /etc/kubernetes/scheduler.conf
          name: kubeconfig
          readOnly: true
   +    - mountPath: /etc/kubernetes/coscheduling-config.yaml
   +      name: coscheduling-config
   +      readOnly: true
      hostNetwork: true
      priorityClassName: system-node-critical
      volumes:
   @@ -54,4 +58,8 @@
          path: /etc/kubernetes/scheduler.conf
          type: FileOrCreate
        name: kubeconfig
   +  - hostPath:
   +      path: /etc/kubernetes/coscheduling-config.yaml
   +      type: File
   +    name: coscheduling-config
    status: {}
   

5. 驗證 kube-scheduler pod 是否正常運行，確認 image 是否爲 k8s.gcr.io/scheduler-plugins/kube-scheduler:v0.18.9

   $ kubectl get pod -n kube-system | grep kube-scheduler
   kube-scheduler-xqcluster-control-plane            1/1     Running   0          3m27s
   
   $ kubectl get pods -l component=kube-scheduler -n kube-system -o=jsonpath="{.items[0].spec.containers[0].image}"
   k8s.gcr.io/scheduler-plugins/kube-scheduler:v0.18.9
   

卸載 Scheduler-plugins

1. 刪除測試時創建的資源
2. 恢復 kube-scheduler.yaml 刪除 coscheduling-config.yaml
3. 檢測默認調度器狀態