Dashboard

Dashboard是基於Web的Kubernetes使用者介面。我們可以使用Dashboard將容器化應用程式部署到Kubernetes叢集，對容器化應用程式進行故障排除，並管理叢集本身及其伴隨資源。還可以使用Dashboard來概述群集上執行的應用程式，以及建立或修改單個Kubernetes資源（例如部署，作業，守護程序等）。例如，我們可以使用部署嚮導擴充套件部署，啟動滾動更新，重新啟動Pod或部署新應用程式。Dashboard還提供有關群集中Kubernetes資源狀態以及可能發生的任何錯誤的資訊

我們先獲取kubernetes官方的Dashboard的yaml檔案

wget https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/recommended/kubernetes-dashboard.yaml
 

建立pod

kubectl create -f kubernetes-dashboard.yaml

訪問 website

kubectl cluster-info
//可以看到這樣的資訊,我們需要訪問得到的網址。
Kubernetes master is running at https://10.20.2.224:6443
KubeDns is running at https://10.20.2.224:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

可以使用apiserver訪問以及proxy訪問，apiserver訪問會出現 “code” 403 錯誤，因為我們物理機的瀏覽器使用匿名證書，沒有可用的證書去訪問 Dashboard，而apiserver使用了TLS認證，所以導致無法訪問。官方推薦了方法，但是因為我的叢集是使用 kubeadm 安裝的所以適用，下面網站，感興趣的朋友可以去看看。

網站：https://github.com/kubernetes/dashboard/wiki/Accessing-Dashboard---1.7.X-and-above 

所以我們使用proxy方式訪問：

kubectl proxy --address=10.20.2.224 --disable-filter=true

這時候訪問可以得到：

所以我們使用proxy方式訪問：提供了兩種方式進行認證兩種方式，也可以選著直接跳過認證，跳過認證會有很多的 system 的警告!可以確定我們沒有認證。使用 token 認證的話需要執行：

kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')
 

獲取 token 但是！因為我們是使用預設的 yaml 檔案建立的 pod 所以，我們並沒有 admin 許可權，所以就算獲取了也不會有太大用，大家也可以選擇建立 admin 使用者，下面我提供的是另一種方法。我們更改 RoleBinding的許可權：

vim kubernetes-dashboard.yaml

更改為：

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
roleRef:
   apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

最後執行下面命令，更新 pod，然後訪問

kubectl replace -f kubernetes-dashboard.yaml

可以看到：

下面是全部的 kubernetes-dashboard.yaml 檔案：

# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# ------------------- Dashboard Secret ------------------- #

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque

---
# ------------------- Dashboard Service Account ------------------- #

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Role & Role Binding ------------------- #

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
rules:
  # Allow Dashboard to create 'kubernetes-dashboard-key-holder' secret.
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["create"]
  # Allow Dashboard to create 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["create"]
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
- apiGroups: [""]
  resources: ["secrets"]
  resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs"]
  verbs: ["get", "update", "delete"]
  # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["kubernetes-dashboard-settings"]
  verbs: ["get", "update"]
  # Allow Dashboard to get metrics from heapster.
- apiGroups: [""]
  resources: ["services"]
  resourceNames: ["heapster"]
  verbs: ["proxy"]
- apiGroups: [""]
  resources: ["services/proxy"]
  resourceNames: ["heapster", "http:heapster:", "https:heapster:"]
  verbs: ["get"]

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system

---
# ------------------- Dashboard Deployment ------------------- #

kind: Deployment
apiVersion: apps/v1beta2
metadata:
  labels:
      k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
      matchLabels:
        k8s-app: kubernetes-dashboard
   template:
      metadata:
        labels:
          k8s-app: kubernetes-dashboard
spec:
  containers:
  - name: kubernetes-dashboard
    image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.0
    ports:
    - containerPort: 8443
      protocol: TCP
    args:
      - --auto-generate-certificates
      # Uncomment the following line to manually specify Kubernetes API server Host
      # If not specified, Dashboard will attempt to auto discover the API server and connect
      # to it. Uncomment only if the default does not work.
      # - --apiserver-host=http://my-address:port
    volumeMounts:
    - name: kubernetes-dashboard-certs
      mountPath: /certs
      # Create on-disk volume to store exec logs
    - mountPath: /tmp
      name: tmp-volume
    livenessProbe:
      httpGet:
        scheme: HTTPS
        path: /
        port: 8443
      initialDelaySeconds: 30
      timeoutSeconds: 30
  volumes:
  - name: kubernetes-dashboard-certs
    secret:
      secretName: kubernetes-dashboard-certs
  - name: tmp-volume
    emptyDir: {}
  serviceAccountName: kubernetes-dashboard
  # Comment the following tolerations if Dashboard must not be deployed on master
  tolerations:
  - key: node-role.kubernetes.io/master
    effect: NoSchedule

---
# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
      k8s-app: kubernetes-dashboard