Linux 安装elasticsearch服务

哈喽，童鞋们， Linux 中安装elasticsearch服务
进入elasticsearch官网下载对应版本的es压缩包
es官网

[2023-07-22T13:20:18,118][ERROR][o.e.b.Elasticsearch      ] [hecs-338293] fatal exception while booting Elasticsearchjava.lang.RuntimeException: can not run elasticsearch as root
	at org.elasticsearch.server@8.8.2/org.elasticsearch.bootstrap.Elasticsearch.initializeNatives(Elasticsearch.java:262)
	at org.elasticsearch.server@8.8.2/org.elasticsearch.bootstrap.Elasticsearch.initPhase2(Elasticsearch.java:161)
	at org.elasticsearch.server@8.8.2/org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:66)

See logs for more details.

ERROR: Elasticsearch did not exit normally - check the logs at /usr/local/elasticsearch-8.8.2/logs/elasticsearch.log

ERROR: Elasticsearch exited unexpectedly

出现这种问题，主要是elasticsearch不让root账户启动，所以需要创建一个非root用户，并切到该非root账户来启动elasticseach服务哦🤔

创建一个用户
```
useradd es-user
```
给该用户设置密码
```
passwd es-user
```
给elasticseach的根目录修改为该账户和用户组
```
chown -R es-user:es-user /usr/local/elasticsearch-8.8.2
```
切换到es-user用户，尝试重新启动elasticsearch服务
```
su es-user
```
```
/usr/local/elasticsearch-8.8.2/bin/elasticsearch
```
如果报错如下：
```
received plaintext http traffic on an https channel, closing connection ...
```
找到/usr/local/elasticsearch-8.8.2/config/目录下面的elasticsearch.yml配置文件，把安全认证开关从原先的true都改成false，实现免密登录访问即可，修改这两处都为false后：

这样之后基本都可以启动成功了！
启动并一直在后台运行（ -d 后台守护执行）
```
/usr/local/elasticsearch-8.8.2/bin/elasticsearch -d
```
浏览器访问http://ip:9200，出现下面的信息就是安装成功了哦