Elasticsearch 入门系列一：安装 elasticsearch

运行下面的命令，拉取 Elasticsearch 镜像并启动容器：

# 创建一个 network，将被用于 Elasticsearch 和 Kibana 之间的通信
$ docker network create elastic

# 拉取 Elasticsearch 镜像，这里的版本 `version`，我们选取：`8.9.0`
$ docker pull docker.elastic.co/elasticsearch/elasticsearch:8.9.0

# 启动 docker elasticsearch 镜像
$ docker run --name elasticsearch --net elastic -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" -t docker.elastic.co/elasticsearch/elasticsearch:8.9.0

以上命令可以用一个 docker-compose 替换：

version: '3'

services:
	elasticsearch:  
	    image: docker.elastic.co/elasticsearch/elasticsearch:8.9.0  
	    container_name: elasticsearch  
	    environment:  
	      # 只在单节点上运行  
	      - discovery.type=single-node  
	    ports:  
	      - "9200:9200"  
	      - "9300:9300"  
	    networks:  
	      - elastic  

networks:  
  elastic:  
    driver: bridge

然后用下面的命令启动容器：

$ docker-compose up

进入ES容器，修改 elasticsearch 用户密码

$ docker exec -it elasticsearch /bin/bash

# 执行命令，按照提示设置密码
$ bin/elasticsearch-reset-password --username elastic -i

WARNING: Owner of file [/usr/share/elasticsearch/config/users] used to be [root], but now is [elasticsearch]
WARNING: Owner of file [/usr/share/elasticsearch/config/users_roles] used to be [root], but now is [elasticsearch]
This tool will reset the password of the [elastic] user.
You will be prompted to enter the password.
Please confirm that you would like to continue [y/N]

验证Elasticsearch是否运行：使用以下命令验证Elasticsearch是否正在Docker容器中运行：

$ curl https://localhost:9200/ --insecure

说明一下，ES 从 8.0 版本开始默认开启 HTTPS，同时是一个自签名证书，因此需要添加 -k 或 --insecure 选项，这将忽略 SSL 证书的验证

请求之后发现服务端响应 401，如下：

curl https://localhost:9200/ --insecure

{"error":{"root_cause":[{"type":"security_exception","reason":"missing authentication credentials for REST request [/]","header":{"WWW-Authenticate":["Basic realm=\"security\" charset=\"UTF-8\"","Bearer realm=\"security\"","ApiKey"]}}],"type":"security_exception","reason":"missing authentication credentials for REST request [/]","header":{"WWW-Authenticate":["Basic realm=\"security\" charset=\"UTF-8\"","Bearer realm=\"security\"","ApiKey"]}},"status":401}%

要使用 curl 发送带有身份验证凭据的请求，可以使用 -u 或 --user 选项。该选项允许指定用户名和密码。当使用该选项时，curl 会自动将凭据发送到服务器。

$ curl -u <username>:<password> https://example.com

需要注意的是，ES 用的是 Basic Authentication，可以将凭据放在 URL 中，而不是使用 -u 选项。以下是使用 URL 指定凭据的命令格式：

$ curl https://<username>:<password>@example.com

比如这里我们用这个命令：

$ curl https://elastic:elastic@localhost:9200/ --insecure

补充一下，也可以用浏览器访问 https://localhost:9200/ 地址，会弹出一个认证弹窗

如果Elasticsearch正在运行，应该能够看到类似于以下内容的输出：

{
  "name" : "50c4f4084c64",
  "cluster_name" : "docker-cluster",
  "cluster_uuid" : "INtSGd02QCWhEvBbafzBjQ",
  "version" : {
    "number" : "8.9.0",
    "build_flavor" : "default",
    "build_type" : "docker",
    "build_hash" : "8aa461beb06aa0417a231c345a1b8c38fb498a0d",
    "build_date" : "2023-07-19T14:43:58.555259655Z",
    "build_snapshot" : false,
    "lucene_version" : "9.7.0",
    "minimum_wire_compatibility_version" : "7.17.0",
    "minimum_index_compatibility_version" : "7.0.0"
  },
  "tagline" : "You Know, for Search"
}