singlenode-es

• 数据存储采用 hostpath 方式

• Pod 多节点反亲和性调度，单节点失效

• Node 调度， 只运行在指定的节点上

[root@master test]# cat singlenode-es-statefulset.yaml 
#外部web访问服务
apiVersion: v1
kind: Service
metadata:
  labels:
    app: elasticsearch
  name: elasticsearch-node
spec:
  type: NodePort
  ports:
    - name: http
      port: 9200
      targetPort: 9200
      nodePort: 30920
    - name: transport
      port: 9300
      targetPort: 9300
      nodePort: 30930
  selector:
    app: elasticsearch
---
# 内部访问服务
apiVersion: v1
kind: Service
metadata:
  name: elasticsearch-headless
  labels:
    app: elasticsearch
spec:
  type: ClusterIP
  clusterIP: None
  ports:
    - name: http
      port: 9200
      targetPort: 9200
    - name: transport
      port: 9300
      targetPort: 9300
  selector:
    app: elasticsearch
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: elasticsearch
  labels:
    app: elasticsearch
spec:
  serviceName: elasticsearch-headless
  replicas: 1
  selector:
    matchLabels:
      app: elasticsearch
  template:
    metadata:
      labels:
        app: elasticsearch
    spec:
      # 节点打上中间件标签并污染：kubectl taint nodes <node-name> middleware=true:NoSchedule
      #tolerations:
      #  - key: "middleware"
      #    operator: "Equal"
      #    value: "true"
      #    effect: "NoSchedule"
      
      # 当多节点生效：不允许同一个pod调度到同一个节点
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            - labelSelector:
                matchExpressions:
                  - key: "app"
                    operator: In
                    values:
                      - middleware
              topologyKey: "kubernetes.io/hostname"
      #securityContext:
      #  fsGroup: 1000
      initContainers:
        - name: init-singlenode-es
          image: busybox
          command: ['sh', '-c', 'chmod -R 777 /data/k8s/elasticsearch']
          volumeMounts:
            - name: elasticsearch-data
              mountPath: /data/k8s/elasticsearch/data
      containers:
        - name: elasticsearch
          image: elasticsearch:7.8.0
          imagePullPolicy: IfNotPresent
          resources:
            limits:
              memory: "2Gi"
              cpu: "1"
          env:
            - name: TZ
              value: America/Sao_Paulo # 巴西: America/Sao_Paulo; 上海：Asia/Shanghai
            - name: cluster.name
              value: elasticsearch
            - name: discovery.type
              value: single-node
            - name: http.max_content_length
              value: 1gb
          ports:
            - containerPort: 9200
              name: http
            - containerPort: 9300
              name: transport
          volumeMounts:
            - name: elasticsearch-data
              mountPath: /usr/share/elasticsearch/data
            - name: elasticsearch-plugins
              mountPath: /usr/share/elasticsearch/plugins
      volumes:
        - name: elasticsearch-data
          hostPath:
            path: /data/k8s/elasticsearch/data
        - name: elasticsearch-plugins
          hostPath:
            path: /data/k8s/elasticsearch/plugins