docker容器的DNS

一 容器默认使用宿主机的DNS

1.1 查看宿主机DNS

~# systemd-resolve --status|grep -A1 -i "DNS Server"
  Current DNS Server: 202.106.0.20
         DNS Servers: 202.106.0.20

1.2 查看容器的DNS

~# docker run -it --rm alpine cat /etc/resolv.conf
nameserver 202.106.0.20

二 命令行指定DNS

~# docker run -it --rm --dns 8.8.8.8 --dns 114.114.114.114  alpine cat /etc/resolv.conf
nameserver 8.8.8.8
nameserver 114.114.114.114

三 在daemon.json指定DNS

3.1 修改daemon.json

~# cat /etc/docker/daemon.json 
{
  "dns":["114.114.114.114","8.8.8.8"] 
}

3.2 重启docker服务

~# systemctl restart docker

3.3 验证容器DNS

~# docker run -it --rm   alpine cat /etc/resolv.conf
nameserver 114.114.114.114
nameserver 8.8.8.8