shell script and config files

interfaces

iface eth0 inet manual
    up ifconfig $IFACE 0.0.0.0 up
    down ifconfig $IFACE down

iface eth1 inet manual
    up ifconfig $IFACE 0.0.0.0 up
    down ifconfig $IFACE down

multi.conf

description     "Multi network manager"

start on networking
stop on runlevel [!2345]

respawn
respawn limit unlimited

# 'sshd -D' leaks stderr and confuses things in conjunction with 'console log'
console none

exec /usr/local/sbin/multi_client -c /etc/init/multi.yaml -d

multi.sh

apt-get update
apt-get install cmake git libiw-dev libglib2.0-dev libyaml-dev libmnl-dev build-essential
ip link set eth1 up
ip link set eth0 up
git clone https://gist.github.com/b73d74997de0d4ca5d67.git
cd b73d74997de0d4ca5d67
git clone https://github.com/kristrev/multi
cd multi
cmake src
make
make install
cd ..
cp multi.conf /etc/init/multi.conf
cp interfaces /etc/network/interfaces
echo "Please enter only the 4th block of the IP address.  Example: if you enter 201, addresses will be given to 192.168.100.201 and 103.52.94.201: "
read SERVERIP
echo "You entered: $SERVERIP.  Addresses will be assigned as: 192.168.100.$SERVERIP and 103.52.94.$SERVERIP"
cat multi.yaml | sed -e "s/192.168.100.201/192.168.100.$SERVERIP/" | sed -e "s/103.52.94.201/103.52.94.$SERVERIP/" > /etc/init/multi.yaml
echo "Confirm correct application of settings:"
cat /etc/init/multi.yaml
echo "You're about to lose your SSH connection.  Server will be accessible at 192.168.100.$SERVERIP and 103.52.94.$SERVERIP.  Hold onto your ass!"
multi_client -c /etc/init/multi.yaml -d

multi.yaml

eth0:
    proto: 'static'
    address: 192.168.100.201
    netmask: 255.255.255.0
    gateway: 192.168.100.1
    metric: 4

eth1:
    proto: 'static'
    address: 103.52.94.201
    netmask: 255.255.255.0
    gateway: 103.52.94.1
    metric: 5