#!/bin/bash

#################################################################
###     bash <(curl -fsSL https://raw.lhy.life/systemd-networkd.sh) [dhcp]
#################################################################

IFACE=$(ip route | awk '/default/ {print $5}')
IP_ADDR=$(ip -4 addr show "$IFACE" | awk '/inet / {print $2}')
GATEWAY=$(ip route | awk '/default/ {print $3}')
MAC_ADDR=$(cat /sys/class/net/"$IFACE"/address)


if [ "$#" -gt 0 ]
then
cat << EOF > /etc/systemd/network/10-nic0.network
[Match]
MACAddress=$MAC_ADDR
Type=ether

[Link]
RequiredForOnline=yes

[Network]
DHCP=ipv4
LinkLocalAddressing=no

[DHCPv4]
UseDNS=false
UseRoutes=false
UseGateway=true
EOF
else
cat << EOF > /etc/systemd/network/10-nic0.network
[Match]
MACAddress=$MAC_ADDR
Type=ether

[Link]
RequiredForOnline=yes

[Network]
Address=$IP_ADDR
Gateway=$GATEWAY
LinkLocalAddressing=no
EOF
fi

systemctl disable networking.service
systemctl enable systemd-networkd.service
mv /etc/network/interfaces /etc/network/interfaces1.bak
cat /etc/systemd/network/10-nic0.network

## apt purge dhcpcd-base* isc-dhcp* -y
## apt autopurge

echo '✅ set dns server:'
echo 'echo "nameserver 1.1.1.1" > /etc/resolv.conf'
echo '✅ reboot or systemctl restart systemd-networkd'