kubernetes集群部署elasticsearch集群，包含无认证和有认证模式

1、背景：

因公司业务需要，需要在测试、生产kubernetes集群中部署elasticsearch集群，因不同环境要求，需要部署不同模式的elasticsearch集群，

1、测试环境因安全性要求不高，是部署一套默认配置；

2、生产环境因安全性要求，是部署一套带认证配置；

2、开发elasticsearch集群，无认证模式：

在kubernetes集群中部署elasticsearch集群，采用的是，有状态服务组件，就是StatefulSet组件。

1. 开发yaml文件内容如下：

# vim elasticsearch.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: es7-cluster
  namespace: sit
spec:
  serviceName: elasticsearch
  replicas: 3
  selector:
    matchLabels:
      app: elasticsearch
  template:
    metadata:
      labels:
        app: elasticsearch
    spec:
      containers:
      - name: elasticsearch
        image: 192.20.67.250/public/elasticsearch:7.9.3
        resources:
            limits:
              cpu: 1000m
            requests:
              cpu: 100m
        ports:
        - containerPort: 9200
          name: rest
          protocol: TCP
        - containerPort: 9300
          name: inter-node
          protocol: TCP
        volumeMounts:
        - name: data
          mountPath: /usr/share/elasticsearch/data
        env:
          - name: cluster.name
            value: k8s-logs
          - name: node.name
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: discovery.zen.minimum_master_nodes
            value: "2"
          - name: discovery.seed_hosts
            value: "es7-cluster-0.elasticsearch,es7-cluster-1.elasticsearch,es7-cluster-2.elasticsearch"
          - name: cluster.initial_master_nodes
            value: "es7-cluster-0,es7-cluster-1,es7-cluster-2"
          - name: ES_JAVA_OPTS
            value: "-Xms1g -Xmx1g"
      initContainers:
      - name: fix-permissions
        image: 192.20.67.250/public/busybox:latest
        command: ["sh", "-c", "chown -R 1000:1000 /usr/share/elasticsearch/data&