RedHat linux服务器安装elasticsearch且设置公网访问

0. 首先需要安装jdk，因为elasticsearch是Java写的，默认需要Java环境，且安装elasticsearch 7.x需要使用jdk 1.8或更高版本

1. 执行以下命令，创建elasticsearch仓库（计划安装7.x版本的elasticsearch）

cat <<EOF | sudo tee /etc/yum.repos.d/elasticsearch.repo
[elasticsearch-7.x]
name=Elasticsearch repository for 7.x packages
baseurl=https://artifacts.elastic.co/packages/oss-7.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md
EOF

2. 建立elasticsearch仓库之后，需要刷新yum索引

sudo yum clean all
sudo yum makecache

3. 安装elasticsearch

sudo yum -y install elasticsearch-oss

4. 编辑文件： /etc/elasticsearch/jvm.options， 设置内存大小：

默认是：-Xms1g -Xmx1g

可以设置为：-Xms256m -Xmx512m

5. 启动elasticsearch

sudo systemctl enable --now elasticsearch.service 

使用如下命令也可以启动

/etc/init.d/elasticsearch start

6. 检验一下是否启动起来了

[root@localhost ~]# curl http://localhost:9200
{
  "name" : "localhost.localdomain",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "Ybtkma76SSKOmXw89fMnuQ",
  "version" : {
    "number" : "7.3.2",
    "build_flavor" : "oss",
    "build_type" : "rpm",
    "build_hash" : "1c1faf1",
    "build_date" : "2019-09-06T14:40:30.409026Z",
    "build_snapshot" : false,
    "lucene_version" : "8.1.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}
[root@localhost ~]# curl http://127.0.0.1:9200
{
  "name" : "localhost.localdomain",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "Ybtkma76SSKOmXw89fMnuQ",
  "version" : {
    "number" : "7.3.2",
    "build_flavor" : "oss",
    "build_type" : "rpm",
    "build_hash" : "1c1faf1",
    "build_date" : "2019-09-06T14:40:30.409026Z",
    "build_snapshot" : false,
    "lucene_version" : "8.1.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}
[root@localhost ~]#

7. 目前只可以在服务器上使用127.0.0.1与localhost进行访问，如果需要对elasticsearch使用公网访问，还需要将elasticsearch.yum配置添加如下内容：

network.host: 0.0.0.0
http.port: 9200
http.cors.enabled: true
http.cors.allow-origin: "*"
cluster.initial_master_nodes: ["node-1"]

8. 服务器上访问结果：

[root@localhost elasticsearch]# curl http://192.168.1.27:9200/
{
  "name" : "localhost.localdomain",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "Ybtkma76SSKOmXw89fMnuQ",
  "version" : {
    "number" : "7.3.2",
    "build_flavor" : "oss",
    "build_type" : "rpm",
    "build_hash" : "1c1faf1",
    "build_date" : "2019-09-06T14:40:30.409026Z",
    "build_snapshot" : false,
    "lucene_version" : "8.1.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

本地访问结果

C:UsersYFZX-MY-1715>curl http://192.168.1.27:9200
{
  "name" : "localhost.localdomain",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "Ybtkma76SSKOmXw89fMnuQ",
  "version" : {
    "number" : "7.3.2",
    "build_flavor" : "oss",
    "build_type" : "rpm",
    "build_hash" : "1c1faf1",
    "build_date" : "2019-09-06T14:40:30.409026Z",
    "build_snapshot" : false,
    "lucene_version" : "8.1.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

C:UsersYFZX-MY-1715>

 9. 配置过程中，启动elasticsearch怎么着都启动不起来，去看了启动日志（日志文件位置再elasticsearch.yum文件中有描述），报错如下：

[localhost.localdomain] no plugins loaded
[2019-09-19T02:26:21,325][INFO ][o.e.d.DiscoveryModule    ] [localhost.localdomain] using discovery type [zen] and seed hosts providers [settings]
[2019-09-19T02:26:22,172][INFO ][o.e.n.Node               ] [localhost.localdomain] initialized
[2019-09-19T02:26:22,173][INFO ][o.e.n.Node               ] [localhost.localdomain] starting ...
[2019-09-19T02:26:22,508][INFO ][o.e.t.TransportService   ] [localhost.localdomain] publish_address {192.168.1.27:9300}, bound_addresses {[::]:9300}
[2019-09-19T02:26:22,517][INFO ][o.e.b.BootstrapChecks    ] [localhost.localdomain] bound or publishing to a non-loopback address, enforcing bootstrap checks
[2019-09-19T02:26:22,520][ERROR][o.e.b.Bootstrap          ] [localhost.localdomain] node validation exception
[1] bootstrap checks failed
[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
[2019-09-19T02:26:22,549][INFO ][o.e.n.Node               ] [localhost.localdomain] stopping ...
[2019-09-19T02:26:22,596][INFO ][o.e.n.Node               ] [localhost.localdomain] stopped
[2019-09-19T02:26:22,597][INFO ][o.e.n.Node               ] [localhost.localdomain] closing ...
[2019-09-19T02:26:22,618][INFO ][o.e.n.Node               ] [localhost.localdomain] closed

去elasticsearch.yum文件里面添加：

#cluster.initial_master_nodes: ["node-1", "node-2"]
cluster.initial_master_nodes: ["node-1"] 这个的话，这里的node-1是上面一个默认的记得打开就可以了