#!/bin/bash
# Creates a new node by cloning the base (if necessary) and setting network 
# interface configuration.
#
# Example usage:
#    vn-newnode --node 2 --file ~/svn/virtnet/data/topologies/interfaces-topology-02-node-02  --iface neta --iface netb
# creates a virtual machine called node2 using the interfaces file
# interfaces-topology-02-node-2 and sets the internal network names for NIC2 and NIC3
# to neta and netb, respectively.
#
# Assumptions:
# The base VM includes the virtnet SVN repository (specifically the
# relevant interfaces files in data/topologies/)
#
# Design:
#    1. Read the command line input parameters
#    2. Clone the base VM to create the node
#    3. Set the virtual NICs on the node by using VBoxManage modifyvm
#    4. Set the hostname, forwarding and interfaces file on the node using
#       ssh
#    5. Poweroff the node
#
# For more info see: http://sandilands.info/sgordon/virtnet
#
# $Revision$
# $Author$
# $Date$
# $URL$

# Script parameters
# The name of the virtual machine to base the new node on
# This vm must have a snapshot with the same name as the VM name
basevm="base"

# Maximum number of the NIC on base machine, e.g. if
# NIC1: NAT
# NIC2: internal
# NIC3: internal
# NIC4: internal
# then nicmax=4
nicmax=4

# Port forward SSH base 
# E.g. with portbase=2200, then on node3 port will be 2200 + 3 = 2203
portbase=2200

# Guest login
vmusername="root"
vmpassword="network"

# Location of virtnet directory on guest
virtnetpath="/home/network/virtnet"

# Location of interface files: local or base
interfacelocation="local"

# Read input parameters
ifnum=0;
while [ "$1" != "" ]; do
	case $1 in
		-f | --file )	shift;
# interfaces file for the node, e.g. vn-if-topology2-node2
				iffile=$1;
				;;
		-n | --node )	shift;
# node number, e.g. 2
				nodeid=$1;
				;;
		-i | --iface )	shift;
# internal network name, e.g. neta
# Repeat this option, in order, for multiple internal networks, e.g.
# --iface neta --iface netb
				ifnet[$ifnum]=$1;
				ifnum=$(( ${ifnum} + 1 ));
				;;
		* )		usage
				exit 1
	esac
	shift
done

# Name of the new VM
vmname="node${nodeid}";

ifmax=$((${#ifnet[@]} - 1 ));

echo "vn: Starting to create new VM ${vmname}"

# Clone the base VM to create the new VM
echo "vn: Cloning ${basevm} ..."
bash vn-clonebase ${basevm} ${vmname}
clonefail=$?

# Check if the clone failed
if [ "${clonefail}" = "1" ];
then
	echo "vn: Cloning of ${basevm} to ${vmname} failed."
	echo "vn: Maybe the VM ${vmname} already exists and is currently running."
	echo "vn: You should manually remove/rename existing nodes in VirtualBox"
	echo "vn: e.g. change ${vmname} to old-${vmname}, then try to create the "
	echo "vn: topology again."
	echo "vn: ERROR. Exiting."
	exit 1
fi

# Only proceed if VM is not running
VBoxManage list runningvms | cut -d "\"" -f 2 | grep -w ${vmname} > /dev/null
novm=$?
if [ "${novm}" = "0" ];
then
	echo "vn: ${vmname} is already running. You must stop it before modifying the network interfaces"
	echo "vn: ERROR. Exiting."
	exit 1
fi


# Unplug cables on all internal interfaces
for (( nic=2; nic<=${nicmax}; nic++ ));
do
	echo "vn: Disconnecting cable ${nic} on ${vmname}"
	VBoxManage modifyvm ${vmname} --cableconnected${nic} off
done

# Setup the interfaces
for (( n=0; n<=${ifmax}; n++ ));
do
	nic=$(( ${n} + 2 ));

	# Configure NIC and plug in cable
	echo "vn: Configuring NIC ${nic} on ${vmname}"
	VBoxManage modifyvm ${vmname} --nic${nic} intnet --intnet${nic} ${ifnet[${n}]}
	VBoxManage modifyvm ${vmname} --cableconnected${nic} on

	echo "vn: Setting port forwarding on ${vmname}"
	# Set the port for port forwarding on NAT interface
	port=$(( ${portbase} + ${nodeid} ));
	# Grab the existing rule name and delete it (in case its named different than ssh)
	rule=`VBoxManage showvminfo ${vmname} | grep "NIC 1 Rule" | cut -d "=" -f 2 | cut -d "," -f 1 | tr -d ' '`
	VBoxManage modifyvm ${vmname} --natpf1 delete ${rule}
	# Now add a new rule
	VBoxManage modifyvm ${vmname} --natpf1 ssh,tcp,,${port},,22
done


# Start the VM
VBoxManage list runningvms | cut -d "\"" -f 2 | grep -w ${vmname} > /dev/null
novm=$?
if [ "${novm}" = "0" ];
then
	echo "vn: Virtual machine ${vmname} is already running"
else
	VBoxManage startvm --type headless ${vmname}
	echo "vn: Virtual machine ${vmname} is now running"
fi


# Set the hostname on the guest and copy the interfaces file
ifcmd="true"
if [ -n "${iffile}" ];
then
	if [ "${iffile}" != 1 ];
	then
		ifcmd="cp ${iffile} /etc/network/interfaces"
	fi
else
	ifcmd="true ";
fi

# Turn on forwarding if router
# Its a router if more than 1 internal network
if [ ${ifmax} -gt 0 ];
then
	routercmd="sed -i 's/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=1/' /etc/sysctl.conf";
else
	routercmd="true ";
fi
# Delete the old key (since most likely was used for other VMs)
echo "vn: Removing SSH keys"
ssh-keygen -q -f "${HOME}/.ssh/known_hosts" -R [localhost]:${port}

# Use SSH to perform the following on the node:
#  - set the hostname using the script vn-sethostname
#  - configure forwarding (if necessary)
#  - copy the interface file to /etc/network/interfaces
#  - poweroff the node
echo "vn: Setting interfaces on guest using SSH ..."
idfile="`dirname $BASH_SOURCE`/../../data/defaults/root/.ssh/id_rsa"
ssh -o "StrictHostKeyChecking no" -l ${vmusername} -i ${idfile} -p ${port} 127.0.0.1 "${virtnetpath}/bin/vn-sethostname ${basevm} ${vmname}"
ssh -o "StrictHostKeyChecking no" -l ${vmusername} -i ${idfile} -p ${port} 127.0.0.1 "${routercmd}"
# Copy the topology file to the VM, rather than using the topology file on it
if [ "${interfacelocation}" = "local" ];
then
	scp -o "StrictHostKeyChecking no" -i ${idfile} -P ${port} ${iffile} ${vmusername}@127.0.0.1:/etc/network/interfaces
else
	ssh -o "StrictHostKeyChecking no" -l ${vmusername} -i ${idfile} -p ${port} 127.0.0.1 "${ifcmd}"
fi
ssh -o "StrictHostKeyChecking no" -l ${vmusername} -i ${idfile} -p ${port} 127.0.0.1 "poweroff"

echo "vn: New VM ${vmname} has been created"

exit 0