1. 进入容器内部
    2. docker exec -it elasticsearch /bin/bash
    4. 在线下载并安装
    5. ./bin/elasticsearch-plugin  install https://github.com/medcl/elasticsearch-analysis-ik/releases/download/v7.12.1/elasticsearch-analysis-ik-7.12.1.zip
    6. #退出
    7. exit
    8. #重启容器
    9. docker restart elasticsearch