Docker是什么？
Docker是一個虛擬環境容器，可以將你的開發環境、代碼、配置文件等一並打包到這個容器中，並發布和應用到任意平台中。
Homebrew安裝
Homebrew的Cask已經支持Docker for Mac，因此可以方便的使用Homebrew Cask來進行安裝。
➜ ~ brew cask install docker
==> Tapping homebrew/cask
Cloning into '/usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask'...
remote: Enumerating objects: 4197, done.
remote: Counting objects: 100% (4197/4197), done.
remote: Compressing objects: 100% (4178/4178), done.
remote: Total 4197 (delta 26), reused 661 (delta 16), pack-reused 0
Receiving objects: 100% (4197/4197), 1.33 MiB | 931.00 KiB/s, done.
Resolving deltas: 100% (26/26), done.
Tapped 1 command and 4098 casks (4,207 files, 4.2MB).
==> Satisfying dependencies
==> Downloading https://download.docker.com/mac/stable/30215/Docker.dmg
######################################################################## 100.0%
==> Verifying SHA-256 checksum for Cask 'docker'.
==> Installing Cask docker
==> Moving App 'Docker.app' to '/Applications/Docker.app'.
🍺 docker was successfully installed!
安裝完成之后，桌面有一個小鯨魚icon,雙擊就可以啟動docker.
docker簡單驗證
1、基本信息查看
➜ ~ docker --version
Docker version 18.09.1, build 4c52b90
➜ ~ docker-compose --version
docker-compose version 1.23.2, build 1110ad01
➜ ~ docker-machine --version
docker-machine version 0.16.1, build cce350d7
➜ ~ docker info
Containers: 0
Running: 0
2、運行nginx服務器：
docker run -d -p 80:80 --name webserver nginx
3、停止刪除Nginx服務器
➜ ~ docker stop webserver
webserver
➜ ~ docker rm webserver
webserver
4、鏡像下載
docker pull katalonstudio/katalon
5、查看運行的鏡像
docker images