#!/bin/bash

# Please adapt the below variables to your needs
# WARNING: any existing configuration in /etc/systemd/network
# will be trashed by this script.
# Backup before or run in a container/VM, whatever
# Afterwards, set TRASH_MY_NETWORK_CONFIG=yesplease and go ahead

ETH_MODULE=igb
ETH_IFACE=enp11s0f0

[ "$TRASH_MY_NETWORK_CONFIG" = "yesplease" ] || exit 1

VLANS=$1

if [ -z "$VLANS" ]; then
    echo "Usage: $0 <# of VLANs>"
    exit 1
fi

rm -rf /etc/systemd/network
mkdir -p /etc/systemd/network

echo "[Match]
Name=test*" > /etc/systemd/network/00-test.network

echo "[Match]
Name=$ETH_IFACE

[Network]" > /etc/systemd/network/00-trunk.network

for ((i=1; i <= VLANS; ++i)); do
    echo "[NetDev]
Name=test-$i
Kind=vlan

[VLAN]
Id=$i" > /etc/systemd/network/test-$i.netdev;

    echo "VLAN=test-$i" >> /etc/systemd/network/00-trunk.network
done

rmmod "$ETH_MODULE"
systemctl stop systemd-networkd
CURSOR=$(journalctl -n0 --show-cursor | awk '/^-- cursor:/ {print $3}')
modprobe "$ETH_MODULE"
systemctl start systemd-networkd

sleep 5

ip link
echo
journalctl --no-pager -u systemd-networkd --cursor "$CURSOR"