raspberry-pi-setup.sh

#!/usr/bin/env bash

sudo apt-get install -y ifenslave

sudo sed -i '/^denyinterfaces eth0 wlan0 bond0$/d' /etc/dhcpcd.conf
cat <<EOS | sudo tee -a /etc/dhcpcd.conf
denyinterfaces eth0 wlan0 bond0
EOS

cat <<EOS | sudo tee /etc/modprobe.d/bonding.conf
options bonding fail_over_mac=none mode=active-backup primary=eth0 primary_reselect=always
EOS

cat <<EOS | sudo tee /etc/network/interfaces.d/bond0
auto lo
iface lo inet loopback

auto eth0
allow-hotplug eth0
iface eth0 inet manual

auto wlan0
allow-hotplug wlan0
iface wlan0 inet manual
  wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

auto bond0
iface bond0 inet dhcp
  bond-slaves           eth0 wlan0
  bond-primary          eth0
  bond-mode             active-backup
  bond-miimon           100
  bond-fail_over_mac    none
  bond-primary_reselect always
  bond-updelay          0
  bond-downdelay        0
  hw-address            b8:27:eb:09:93:3b
EOS