K8S資源管理總結及dashboard創建

K8S資源管理總結及dashboard創建

K8S核心資源管理方法：

• 陳述式管理：基於眾多kubectl命令
• 聲明式管理：基於k8s資源配置清單
• GUI式管理：基於K8S儀表盤（dashboard）

K8S四種核心的附件

CNI網絡插件：如果集群足夠小，其實不需要網絡插件，只需要改iptables規則，增加幾條路由就可以了。

在恰當的時候，用恰當的技術，解決恰當的問題。

• CNI網絡插件

  • flannel（在100台機器的規模內）
  • 三種常用工作模式
    • NAT
    • VxLAN
  • 優化SNAT規則（集群內容器通信，能獲取到具體的容器IP，而不是宿主機IP）

• K8S的服務發現

  • 集群網絡：clusterIP
  • Service資源：Service Name
  • CoreDNS軟件：實現了Service Name和Cluster IP的自動關聯

• K8S的服務暴露

  • Ingress資源：專用於暴露7層應用到K8S集群外的一種核心資源（http/https）
  • ingress controller：一個簡化版的nginx（調度流量）+go腳本（動態識別yaml）
  • Traefik軟件：實現了ingress控制器的一個軟件

• GUI圖形化管理插件

開始安裝dashboard

在運維主機上hdss7-200

[root@hdss7-200 k8s-yaml]# docker pull k8scn/kubernetes-dashboard-amd64:v1.8.3
[root@hdss7-200 k8s-yaml]# docker images | grep dashboard
k8scn/kubernetes-dashboard-amd64   v1.8.3     fcac9aa03fd6     2 years ago         102MB
[root@hdss7-200 k8s-yaml]# docker tag fcac9aa03fd6 harbor.od.com/public/dashboard.od.com:v1.8.3
[root@hdss7-200 k8s-yaml]# docker push !$

rbac.yaml

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

dp.yaml

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: ''
    spec:
      priorityClassName: system-cluster-critical
      containers:
      - name: kubernetes-dashboard
        image: harbor.od.com/public/dashboard: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: tmp-volume
          mountPath: /tmp
        livenessProbe:
          httpGet:
            scheme: HTTPS
            path: /
            port: 8443
          initialDelaySeconds: 30
          timeoutSeconds: 30
      volumes:
      - name: tmp-volume
        emptyDir: {}
      serviceAccountName: kubernetes-dashboard-admin
      tolerations:
      - key: "CriticalAddonsOnly"
        operator: "Exists"

          - --auto-generate-certificates
          # 自動生成證書
          livenessProbe:
          # 容器存活性探針
          # 容器就緒性探針
          # 目標是判定容器在K8S容器編排環境下是否正常啟動，或者運行的過程中是否有異常退出
          # 就緒性探針
          # 容器被拉起來之后，先用就緒性探針去探測它，直到它滿足我的要求，我認定它為就緒狀態，就是running狀態
            port: 8443
            # 監聽8443是否存在，存在則說明容器是正常狀態

svc.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:
  selector:
    k8s-app: kubernetes-dashboard
  ports:
  - port: 443
    targetPort: 8443

ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: kubernetes-dashboard
  namespace: kube-system
  annotations:
    kubernetes.io/ingress.class: traefik
spec:
  rules:
  - host: dashboard.od.com
    http:
      paths:
      - backend:
          serviceName: kubernetes-dashboard
          servicePort: 443

創建資源

[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/rbac.yaml
serviceaccount/kubernetes-dashboard-admin created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-admin created

[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/dp.yaml
deployment.apps/kubernetes-dashboard created

[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/svc.yaml
service/kubernetes-dashboard created

[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/ingress.yaml
ingress.extensions/kubernetes-dashboard created

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