Kubernetes集群中部署dashboard

部署 dashboard 插件

下载k8s后的解压缩目录结构：kubernetes/cluster/addons/dashboard

使用的文件：

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

• 新加了 dashboard-rbac.yaml 文件，定义 dashboard 使用的 RoleBinding。

由于 kube-apiserver 启用了 RBAC 授权，而官方源码目录的 dashboard-controller.yaml 没有定义授权的 ServiceAccount，所以后续访问 kube-apiserver 的 API 时会被拒绝.

解决办法是：定义一个名为 dashboard 的 ServiceAccount，然后将它和 Cluster Role view 绑定。参考下面修改的文件。

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

• 指定端口类型为 NodePort，这样外界可以通过地址 nodeIP:nodePort 访问 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

• 使用名为 dashboard 的自定义 ServiceAccount；

执行所有定义文件

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

检查执行结果

查看分配的 NodePort

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

• NodePort 30312映射到 dashboard pod 80端口；

检查 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

访问dashboard

1. kubernetes-dashboard 服务暴露了 NodePort，可以使用 http://NodeIP:nodePort 地址访问 dashboard；
2. 通过 kube-apiserver 访问 dashboard；
3. 通过 kubectl proxy 访问 dashboard：

通过 kubectl proxy访问dashboard

启动代理

$ 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 选项，否则浏览器访问 dashboard 页面时提示 “Unauthorized”；

浏览器访问 URL：http://10.501.101.41:8086/ui
自动跳转到：http://10.501.101.41:8086/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard/#/workload?namespace=default

通过 kube-apiserver 访问dashboard

获取集群服务地址列表

$ 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

由于 kube-apiserver 开启了 RBAC 授权，而浏览器访问 kube-apiserver 的时候使用的是匿名证书，所以访问安全端口会导致授权失败。这里需要使用非安全端口访问 kube-apiserver：

浏览器访问 URL：http://10.501.101.41:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard

由于缺少 Heapster 插件，当前 dashboard 不能展示 Pod、Nodes 的 CPU、内存等 metric 图形；

欢迎订阅微信公众号