一，让systemd-resolved不使用127.0.0.53
systemd-resolved会产出两个运行配置，如下
/run/systemd/resolve/resolv.conf #路径1
/run/systemd/resolve/stub-resolv.conf #路径2/etc/resolv.conf 默认已经软链接到/run/systemd/resolve/stub-resolv.conf（路径2），那么只需将/etc/resolv.conf 软链接到/run/systemd/resolve/resolv.conf（路径1）
而/run/systemd/resolve/* 下的配置文件是由/etc/systemd/resolved.conf 决定的，可以用下边的配置脚本，取消指向127.0.0.53，并关闭127.0.0.53的监听。
mkdir -p /etc/systemd/resolved.conf.d/
cat >/etc/systemd/resolved.conf.d/99-dns.conf << EOF
[Resolve]
DNS=1.1.1.1 8.8.8.8
DNSStubListener=no
EOF
ln -s -f /run/systemd/resolve/resolv.conf /etc/resolv.conf
systemctl daemon-reload && systemctl restart systemd-resolved.service
cat /etc/resolv.conf二，夺回/etc/resolv.conf的控制权
下文所述适用于ubuntu 16.10及更新的版本
systemctl disable --now systemd-resolved.service
rm /etc/resolv.conf
cat >/etc/resolv.conf << EOF
nameserver 8.8.8.8
nameserver 1.1.1.1
EOF
chmod 0644 /etc/resolv.conf