Kubernetes部署ElasticSearch集群

ElasticSearch跟MySQL类似，都需要使用StatefulSet去部署这类有状态服务

es配置中常见的参数：

• cluster.name：集群名称，确保同一集群中的节点此配置名称相同
• node.name：节点名称，表示集群中节点名称
• network.host：es监听的IP地址
• discovery.seed_hosts：节点发现地址，配置成域名（域名下解析到多个IP地址），那么es将处理所有发现的IP地址
• cluster.initial_master_nodes：集群内所有的node.name

部署NFS storageclass

参考文章：https://1335402049.github.io/2020/09/16/Kubernetes%E4%B8%AD%E4%BD%BF%E7%94%A8NFS%E7%9A%84StorageClass/

创建namespace

apiVersion: v1
kind: Namespace
metadata:
  name: log-system
  labels:
    name: log-system

创建configmap

apiVersion: v1
kind: ConfigMap
metadata:
  name: es
  namespace: log-system
data:
  elasticsearch.yml: |
    cluster.name: "es-cluster"
    node.name: "${POD_NAME}"
    network.host: 0.0.0.0
    discovery.seed_hosts: "elasticsearch-discovery"
    cluster.initial_master_nodes: "es-0,es-1,es-2"
    http.cors.enabled: "true"
    http.cors.allow-origin: "*"

创建statefulset

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: es
  namespace: log-system
spec:
  replicas: 3
  selector:
    matchLabels:
      app: es
  serviceName: es
  volumeClaimTemplates:
    - metadata:
        name: es-data
        annotations:
          volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"
      spec:
        accessModes:
          - ReadWriteMany
        resources:
          requests:
            storage: 5Gi
  template:
    metadata:
      labels:
        app: es
    spec:
      initContainers:
        - name: increase-vm-max-map
          image: busybox
          imagePullPolicy: IfNotPresent
          command:
            - sysctl
            - -w
            - vm.max_map_count=262144
          securityContext:
            privileged: true
        - name: increase-fd-ulimit
          image: busybox
          imagePullPolicy: IfNotPresent
          command:
            - sh
            - -c
            - ulimit -n 65536
          securityContext:
            privileged: true
      containers:
        - name: elasticsearch
          image: elasticsearch:7.2.0
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 9200
              name: es-cli
            - containerPort: 9300
              name: es-iner
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
          volumeMounts:
            - mountPath: /usr/share/elasticsearch/data
              name: es-data
            - mountPath: /usr/share/elasticsearch/config/elasticsearch.yml
              name: es-config
              subPath: elasticsearch.yml
      volumes:
        - name: es-config
          configMap:
            name: es

创建service

apiVersion: v1
kind: Service
metadata:
  name: es-out
  namespace: log-system
spec:
  type: NodePort
  selector:
    app: es
  ports:
    - port: 9200
      targetPort: 9200
---
apiVersion: v1
kind: Service
metadata:
  name: elasticsearch-discovery
  namespace: log-system
spec:
  clusterIP: None
  ports:
    - port: 9300
      targetPort: 9300
  selector:
    app: es

查看集群状态

查看pod,svc情况

kubectl get pods,svc -n log-system

使用curl访问es-out svc的9200端口，查看集群健康状态

curl http://10.1.213.20:9200/_cat/health?v