部署 dashboard 外掛

下載k8s後的解壓縮目錄結構：kubernetes/cluster/addons/dashboard

使用的檔案：

$ ls *.yaml
dashboard-controller.yaml  dashboard-rbac.yaml  dashboard-service.yaml

• 新加了 dashboard-rbac.yaml 檔案，定義 dashboard 使用的 RoleBinding。

由於 kube-apiserver 啟用了 RBAC 授權，而官方原始碼目錄的 dashboard-controller.yaml 沒有定義授權的 ServiceAccount，所以後續訪問 kube-apiserver

解決辦法是：定義一個名為 dashboard 的 ServiceAccount，然後將它和 Cluster Role view 繫結。參考下面修改的檔案。

dashboard-controller.yaml

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ''
    spec:
      serviceAccountName: dashboard
      containers:
      - name: kubernetes-dashboard
        image: cokabug/kubernetes-dashboard-amd64:v1.6.0
        resources:
          limits:
            cpu: 100m
            memory: 50Mi
          requests:
            cpu: 100m
            memory: 50Mi
        ports:
        - containerPort: 9090
        livenessProbe:
          httpGet:
            path: /
            port: 9090
          initialDelaySeconds: 30
          timeoutSeconds: 30
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"
 

dashboard-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    kubernetes.io/cluster-service: "true"
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  type: NodePort 
  selector:
    k8s-app: kubernetes-dashboard
  ports:
  - port: 80
    targetPort: 9090
 

dashboard-rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard
  namespace: kube-system

---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1alpha1
metadata:
  name: dashboard
subjects:
  - kind: ServiceAccount
    name: dashboard
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

配置dashboard-service

$ diff dashboard-service.yaml.orig dashboard-service.yaml
10a11
>   type: NodePort

• 指定埠型別為 NodePort，這樣外界可以通過地址 nodeIP:nodePort 訪問 dashboard；

配置dashboard-controller

20a21
>       serviceAccountName: dashboard
23c24
<         image: gcr.io/google_containers/kubernetes-dashboard-amd64:v1.6.0
---
>         image: cokabug/kubernetes-dashboard-amd64:v1.6.0

• 使用名為 dashboard 的自定義 ServiceAccount；

執行所有定義檔案

$ pwd
/home/app/kubernetes/cluster/addons/dashboard
$ ls *.yaml
dashboard-controller.yaml  dashboard-rbac.yaml  dashboard-service.yaml
$ kubectl create -f  .
$

檢查執行結果

檢視分配的 NodePort

$ kubectl get services kubernetes-dashboard -n kube-system
NAME                   CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes-dashboard   10.254.224.130   <nodes>       80:30312/TCP   25s

• NodePort 30312對映到 dashboard pod 80埠；

檢查 controller

$ kubectl get deployment kubernetes-dashboard  -n kube-system
NAME                   DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
kubernetes-dashboard   1         1         1            1           3m
$ kubectl get pods  -n kube-system | grep dashboard
kubernetes-dashboard-1339745653-pmn6z   1/1       Running   0          4m

訪問dashboard

1. kubernetes-dashboard 服務暴露了 NodePort，可以使用 http://NodeIP:nodePort 地址訪問 dashboard；
2. 通過 kube-apiserver 訪問 dashboard；
3. 通過 kubectl proxy 訪問 dashboard：

通過 kubectl proxy訪問dashboard

啟動代理

$ kubectl proxy --address='10.501.101.41' --port=8086 --accept-hosts='^*$'
Starting to serve on 10.501.101.41:8086

• 需要指定 --accept-hosts 選項，否則瀏覽器訪問 dashboard 頁面時提示 “Unauthorized”；

瀏覽器訪問 URL：http://10.501.101.41:8086/ui
自動跳轉到：http://10.501.101.41:8086/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard/#/workload?namespace=default

通過 kube-apiserver 訪問dashboard

獲取叢集服務地址列表

$ kubectl cluster-info
Kubernetes master is running at https://10.501.101.41:6443
KubeDNS is running at https://10.501.101.41:6443/api/v1/proxy/namespaces/kube-system/services/kube-dns
kubernetes-dashboard is running at https://10.501.101.41:6443/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

由於 kube-apiserver 開啟了 RBAC 授權，而瀏覽器訪問 kube-apiserver 的時候使用的是匿名證書，所以訪問安全埠會導致授權失敗。這裡需要使用非安全埠訪問 kube-apiserver：

瀏覽器訪問 URL：http://10.501.101.41:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

由於缺少 Heapster 外掛，當前 dashboard 不能展示 Pod、Nodes 的 CPU、記憶體等 metric 圖形；

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