docker 中在容器中安装crontab

1. 安装
   

   apt-get install cron

   apt-get update

2.  启动
   

   service cron status
   service cron start 

3. crontab -e
   如果出现下面的报错：
   no crontab for root - using an empty one
/usr/bin/sensible-editor: 25: /usr/bin/sensible-editor: editor: not found
/usr/bin/sensible-editor: 28: /usr/bin/sensible-editor: nano: not found
/usr/bin/sensible-editor: 31: /usr/bin/sensible-editor: nano-tiny: not found
/usr/bin/sensible-editor: 34: /usr/bin/sensible-editor: vi: not found
Couldn't find an editor!
Set the $EDITOR environment variable to your desired editor.
crontab: "/usr/bin/sensible-editor" exited with status 1
   则先安装vim
   

   apt-get install vim -y