Kubernetes的Resource和Dashboard(十三)

童話述說我的結局發表於2022-01-28

一、Resource和Dashboard

1.1、Resource

因為K8S的最小操作單元是Pod，所以這裡主要討論的是Pod的資源

官網：https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/

 

 在K8S的叢集中，Node節點的資源資訊會上報給APIServer，可以通過下面兩個屬性設定cpu和記憶體大小

  • requests
  • limits

配置檔案案例如下

 apiVersion: v1
 kind: Pod
 metadata:
 name: frontend
 spec:
 containers:
   - name: db
  image: mysql
  env:
     - name: MYSQL_ROOT_PASSWORD
    value: "password"
  resources:
    requests:
      memory: "64Mi"     # 表示64M需要記憶體
      cpu: "250m"        # 表示需要0.25核的CPU
    limits:
      memory: "128Mi"    
      cpu: "500m"
   - name: wp
  image: wordpress
  resources:
    requests:
      memory: "64Mi"
      cpu: "250m"
    limits:
      memory: "128Mi"
      cpu: "500m"

1.2、Dashboard

官網：https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/

Dashboard這玩意在前面文章中我畫過一個圖，也在每個功能模組介紹中也說明過，這玩意其實就是一個圖形化監控介面，下面是官網的說明

 

 (1)根據yaml檔案建立資源dashboard.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    # Allows editing resource and makes sure it is created first.
    addonmanager.kubernetes.io/mode: EnsureExists
  name: kubernetes-dashboard-settings
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
  name: kubernetes-dashboard
  namespace: kube-system
---
apiVersion: apps/v1
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: ''
        seccomp.security.alpha.kubernetes.io/pod: 'docker/default'
    spec:
      priorityClassName: system-cluster-critical
      containers:
      - name: kubernetes-dashboard
        image: registry.cn-hangzhou.aliyuncs.com/ghy/kubernetes-dashboard-amd64:v1.8.3
        resources:
          limits:
            cpu: 100m
            memory: 300Mi
          requests:
            cpu: 50m
            memory: 100Mi
        ports:
        - containerPort: 8443
          protocol: TCP
        args:
          # PLATFORM-SPECIFIC ARGS HERE
          - --auto-generate-certificates
        volumeMounts:
        - name: kubernetes-dashboard-certs
          mountPath: /certs
        - name: tmp-volume
          mountPath: /tmp
        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
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
  name: kubernetes-dashboard-minimal
  namespace: kube-system
rules:
  # 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: RoleBinding
metadata:
  name: kubernetes-dashboard-minimal
  namespace: kube-system
  labels:
    k8s-app: kubernetes-dashboard
    addonmanager.kubernetes.io/mode: Reconcile
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard-minimal
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system
---
apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    # Allows editing resource and makes sure it is created first.
    addonmanager.kubernetes.io/mode: EnsureExists
  name: kubernetes-dashboard-certs
  namespace: kube-system
type: Opaque
---
apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
    # Allows editing resource and makes sure it is created first.
    addonmanager.kubernetes.io/mode: EnsureExists
  name: kubernetes-dashboard-key-holder
  namespace: kube-system
type: Opaque
---
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:
  selector:
    k8s-app: kubernetes-dashboard
  ports:
  - port: 443
    targetPort: 8443
    nodePort: 30018
  type: NodePort

 (2)執行指令碼

kubectl apply -f dashboard.yaml

（3）檢視資源

kubectl get pods -n kube-system
kubectl get pods -n kube-system -o wide
kubectl get svc -n kube-system
kubectl get deploy kubernetes-dashboard -n kube-system

（4）使用火狐瀏覽器訪問

https://ip:30018/

 (5)生成登入需要的token

建立service account

kubectl create sa dashboard-admin -n kube-system

建立角色繫結關係

kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin

檢視dashboard-admin的secret名字

ADMIN_SECRET=$(kubectl get secrets -n kube-system | grep dashboard-admin | awk '{print $1}')
echo ADMIN_SECRET

列印secret的token

kubectl describe secret -n kube-system ${ADMIN_SECRET} | grep -E '^token' | awk '{print $2}'

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