安装ElasticSearch

拉取镜像，选择版本为6.5.0

$ docker pull elasticsearch:6.5.0

查看镜像

$ docker images

启动一个容器

$ docker run --name elasticsearch -d -e ES_JAVA_OPTS="-Xms512m -Xmx512m" -p 9200:9200 -p 9300:9300 elasticsearch:6.5.0
42d639a089348b393b0cc912141ef357b6565996c5c4863e363f8729da229d7d

然后访问 GET localhost:9200 ，发现未启动成功，查看日志

$ docker logs -f 42d6
[2018-12-05T06:07:06,546][INFO ][o.e.b.BootstrapChecks    ] [IHubvTB] bound or publishing to a non-loopback address, enforcing bootstrap checks
ERROR: [1] bootstrap checks failed
[1]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[2018-12-05T06:07:06,630][INFO ][o.e.n.Node               ] [IHubvTB] stopping ...
[2018-12-05T06:07:06,939][INFO ][o.e.n.Node               ] [IHubvTB] stopped
[2018-12-05T06:07:06,939][INFO ][o.e.n.Node               ] [IHubvTB] closing ...
[2018-12-05T06:07:06,973][INFO ][o.e.n.Node               ] [IHubvTB] closed

这里提示：vm.max_map_count [65530] is too low, increase to at least [262144]，说max_map_count的值太小了，需要设大到262144

查看max_map_count的值

$ cat /proc/sys/vm/max_map_count
65530

*(仅临时设置) 重新设置max_map_count的值

$ sysctl -w vm.max_map_count=262144
vm.max_map_count = 262144

再次启动容器

$ docker start 42d6

*(永久设置) 重新设置max_map_count的值

$ cat /proc/sys/vm/max_map_count
$ vim /etc/sysctl.conf

添加一行：

vm.max_map_count=262144

更新配置

$ sysctl -p
$ cat /proc/sys/vm/max_map_count

再次访问 GET localhost:9200

{
    "name": "IHubvTB",
    "cluster_name": "docker-cluster",
    "cluster_uuid": "edN3o1PkTAKF5C4N-Uw7tQ",
    "version": {
        "number": "6.5.0",
        "build_flavor": "default",
        "build_type": "tar",
        "build_hash": "816e6f6",
        "build_date": "2018-11-09T18:58:36.352602Z",
        "build_snapshot": false,
        "lucene_version": "7.5.0",
        "minimum_wire_compatibility_version": "5.6.0",
        "minimum_index_compatibility_version": "5.0.0"
    },
    "tagline": "You Know, for Search"
}

安装成功。

head插件安装

5.x版本head插件安装说明

1.x版本和2.x版本，可以直接使用plugin命令来安装head插件

5.x以上版本，无法通过plugin命令来安装。

https://github.com/mobz/elasticsearch-head 文档说明：

插件不支持，需要借助node来跑一个服务

Running as a plugin of Elasticsearch (deprecated)
for Elasticsearch 5.x: site plugins are not supported. Run as a standalone server
for Elasticsearch 2.x: sudo elasticsearch/bin/plugin install mobz/elasticsearch-head
for Elasticsearch 1.x: sudo elasticsearch/bin/plugin -install mobz/elasticsearch-head/1.x
for Elasticsearch 0.x: sudo elasticsearch/bin/plugin -install mobz/elasticsearch-head/0.9
open http://localhost:9200/_plugin/head/

Running with built in server
git clone git://github.com/mobz/elasticsearch-head.git
cd elasticsearch-head
npm install
npm run start
open http://localhost:9100/
This will start a local webserver running on port 9100 serving elasticsearch-head

或者安装google插件

Running as a Chrome extension
Install ElasticSearch Head from the Chrome Web Store.
Click the extension icon in the toolbar of your web browser.

但是还有一种安装方式，就是通过docker安装，访问地址是http://localhost:9100/

Running with docker
for Elasticsearch 5.x: docker run -p 9100:9100 mobz/elasticsearch-head:5
for Elasticsearch 2.x: docker run -p 9100:9100 mobz/elasticsearch-head:2
for Elasticsearch 1.x: docker run -p 9100:9100 mobz/elasticsearch-head:1
for fans of alpine there is mobz/elasticsearch-head:5-alpine
open http://localhost:9100/

使用docker安装head插件

拉取镜像（这里选择国内镜像源）

$ docker pull mobz/elasticsearch-head

启动容器

$ docker run -d -p 9100:9100 --name elasticsearch-head elasticsearch-head

然后浏览器访问 localhost:9200

出现这个界面，说明head插件安装成功。

但是发现健康值为：未连接？

打开浏览器调试，发现报错信息：

Access to XMLHttpRequest at 'http://localhost:9200/' from origin 'http://localhost:9100' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

这里也就是跨域错误

https://github.com/mobz/elasticsearch-head 文档中也有说明：

Enable CORS in elasticsearch
When not running as a plugin of elasticsearch (which is not even possible from version 5) you must enable CORS in elasticsearch otherwise your browser will rejects requests which appear insecure.

In elasticsearch configuration;

add http.cors.enabled: true
you must also set http.cors.allow-origin because no origin allowed by default. http.cors.allow-origin: "*" is valid value, however it’s considered as a security risk as your cluster is open to cross origin from anywhere.

ElasticSearch跨域设置

进入elasticsearch容器

$ docker exec -it 42d639a08934 /bin/bash

找到配置文件的目录

$ /usr/share/elasticsearch/config
$ ls
elasticsearch.keystore  ingest-geoip  log4j2.properties  roles.yml  users_roles
elasticsearch.yml       jvm.options   role_mapping.yml   users

修改elasticsearch.yml，需要安装vim（参考 https://my.oschina.net/yimingkeji/blog/2978974）

如果提示apt-get不存在，使用yum安装vim

$ yum install -y vim

安装后编辑elasticsearch.yml

$ vim elasticsearch.yml
# ----添加内容----
# head插件设置
http.cors.enabled: true
http.cors.allow-origin: "*"

重启容器

$ docker restart 42d639a08934

再次访问插件

安装完成。