Elasticsearch 7.x外部访问

Elasticsearch单机模式是不允许外部访问的。所以我们需要修改一些配置，将elasticsearch修改为集群模式，比如：cluster.name、node.name、network.host、cluster.initial_master_nodes等参数。

• CentOS 7
• Elasticsearch 7.7.0
• JDK 8

操作说明：

1. 操作系统配置使用root用户进行操作；
2. 我们可以将elasticsearch的9200端口对外开放，也可以通过nginx将端口代理出来，这里我们选择直接关闭防火墙。

具体操作：

1. 关闭防火墙

   # 关闭防火墙
   systemctl stop firewalld
   # 查看防火墙状态
   systemctl status firewalld
   

   ● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
    Docs: man:firewalld(1)
   
   Nov 08 18:16:16 localhost.localdomain systemd[1]: Starting firewalld - 	dynamic firewall daemon...
   Nov 08 18:16:16 localhost.localdomain systemd[1]: Started firewalld - dynamic firewall daemon.
   Nov 08 18:16:17 localhost.localdomain firewalld[7656]: WARNING: 		AllowZoneDrifting is enabled. This is considered an insecure configuration option. It will be removed in>
   Nov 10 22:39:23 localhost.localdomain systemd[1]: Stopping firewalld - dynamic firewall daemon...
   Nov 10 22:39:25 localhost.localdomain systemd[1]: Stopped firewalld - dynamic firewall daemon.
   

Elasticsearch配置使用普通用户权限进行操作；

1. 进入elasticsearch目录，打开config/elasticsearch.yml，对Network模块进行配置，其中192.168.234.129为虚拟机IP：

   # ---------------------------------- Network -----------------------------------
   #
   # Set the bind address to a specific IP (IPv4 or IPv6):
   # 配置为虚拟机IP或者0.0.0.0
   network.host: 192.168.234.129
   #
   # Set a custom port for HTTP:
   #
   http.port: 9200
   #
   # For more information, consult the network module documentation.
   #
   
   

2. 以上配置完成之后保存退出，启动Elasticsearch：

   ./bin/elasticsearch -d
   

3. 启动过程中还会有报错信息，默认的discovery不适合使用，至少需要配置discovery.seed_hosts、discovery.seed_providers和cluster.initial_master_nodes中的一项：

   [1]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured
   

4. 接下来我们继续对config/elasticsearch.yml进行配置：

   # ------------------------------------ Node ------------------------------------
   #
   # Use a descriptive name for the node:
   #
   node.name: node-1
   #
   # Add custom attributes to the node:
   #
   #node.attr.rack: r1
   #
   # --------------------------------- Discovery ----------------------------------
   #
   # Pass an initial list of hosts to perform discovery when this node is started:
   # The default list of hosts is ["127.0.0.1", "[::1]"]
   #
   #discovery.seed_hosts: ["host1", "host2"]
   #
   # Bootstrap the cluster using an initial set of master-eligible nodes:
   #
   cluster.initial_master_nodes: ["node-1"]
   #
   # For more information, consult the discovery and cluster formation module documentation.
   

5. 保存退出，启动Elasticsearch；在本地浏览器地址栏访问http://192.168.234.129:9200/：

   {
   	name: "node-1",
   	cluster_name: "elasticsearch",
   	cluster_uuid: "MZlO8UPyS52AuuCrFwABvQ",
   	version: {
   	number: "7.7.0",
   	build_flavor: "default",
   	build_type: "tar",
   	build_hash: "81a1e9eda8e6183f5237786246f6dced26a10eaf",
   	build_date: "2020-05-12T02:01:37.602180Z",
   	build_snapshot: false,
   	lucene_version: "8.5.1",
   	minimum_wire_compatibility_version: "6.8.0",
   	minimum_index_compatibility_version: "6.0.0-beta1"
   	},
   	tagline: "You Know, for Search"
   }
   

1. Elasticsearch对外访问，需要按照集群的模式进行配置；
2. 配置文件主要是对Node、Network和Discovery三个模块进行配置；
3. Network模块的network.host也可以配置为0.0.0.0；
4. 出现其他错误，可以参考Elasticsearch 7.x安装部署。