#!/bin/bash

#
# mit-kvm - mgmt script for kvm
#
# 
# 08-06-27 tmu Version 0.1
# 08-06-30 tmu new command "config"
#

version="0.2 (08-06-30)"

debug=0
cfg=/etc/mit-kvm.cfg
rootdir="/srv/virt"
rundir="/var/run/mit-kvm"
vmsdir="${rootdir}/vm"

cmd_kvm="/usr/bin/kvm"
cmd_hostname="/bin/hostname"
cmd_find="/usr/bin/find"
cmd_list_sort="/usr/bin/sort -k1 -t, -g" 
cmd_socat="/usr/bin/socat"
cmd_ssh="/usr/bin/ssh"
cmd_mit_kvm="$0"
cmd_editor="/usr/bin/editor"


# KVM defaults
mem=1024
keyboard="de-ch"
cpus="2"
nic_model="e1000"
boot=c

halt_timeout=60
migration_startport="20000"

if [ -f "${cfg}" ]
then	source ${cfg}
fi

function error {
	echo 'mit-kvm[id='${id}']: error: '${1}
	exit 1
}

function warn {
	echo 'mit-kvm[id='${id}']: warn: '${1}
}

function debug {
	
	if [ "$debug" = "1" ]
	then
		echo "mit-kvm[id=$id]: debug: $1"
	fi
	return
}

function rundir_cleanup {
	id=$1
	rm "${rundir}/${id}.pid"
	rm "${rundir}/${id}.args"
	rm "${rundir}/${id}.host"

}

function get_monitor_path {
	vmcfg=$(get_cfg_by_id_or_name $1)
	source $vmcfg

	socket="${rundir}/${id}.socket"

	echo ${socket}
}

function get_cfg_by_id_or_name {
	#debug "function get_cfg_by_id_or_name"

	for i in $(${cmd_find} ${vmsdir} -name config -type f)
	do
		source $i
		if [ "$id" = "$1" ]
		then
			echo $i
			return
		elif [ "$name" = "$1" ]
		then
			echo $i
			return
		fi
	done

	error "not found any vmcfg for $1"
}

function calc_migration_port {
	id="$1"
	
	echo "${migration_startport}+${id}" | bc
}


function do_start {
	vmcfg=$(get_cfg_by_id_or_name $1)
	source $vmcfg

	incoming_options="$2"

	if [ -z "$id" ]; then error "id not defined in $vmcfg"; fi
	if [ -z "$nic_macaddr" ]; then	error "nic_macaddr not defined in $vmcfg."; fi

	vmdir="${vmsdir}/${id}"
	cmdline=""

	# Harddisks / Cdrom
	for i in $(seq 0 4); 
	do
		if [ -n "${drive[$i]}" ]
		then
			cmdline="${cmdline} -drive ${drive[$i]}"
		fi
	done

	# Harddisks / Cdrom
        for i in $(seq 0 4);
        do
                if [ -n "${usbdevice[$i]}" ]
                then
                        cmdline="${cmdline} -usbdevice ${usbdevice[$i]}"
                fi
        done

	
	# Netzwerk
	cmdline="${cmdline} -net tap,ifname=vnet${id} -net nic,model=$nic_model,macaddr=$nic_macaddr"
	
	# Monitor
	cmdline="${cmdline} -monitor unix:${rundir}/${id}.socket,server,nowait "

	# Diverses
	cmdline="${cmdline} -usb -boot ${boot} -k $keyboard -vnc :$id -m $mem -smp $cpus -daemonize -pidfile ${rundir}/${id}.pid -name $name" 

	cd ${vmdir}  || error "can't change to dir $vmdir"

	if ! do_status ${id}
	then
		${cmd_kvm} ${cmdline} ${incoming_options} || error "failure starting vm" 
		${cmd_hostname} > ${rundir}/${id}.host
		echo $cmdline > ${rundir}/${id}.args
	else
		warn "already running"
	fi
}

function do_list {

        for i in  $(${cmd_find} ${vmsdir} -name config -type f)
        do
		id=
		name=
		nic_macaddr=
		source $i
		status="nothere"
		
		if do_status ${id}; then status="running"; fi

                echo "$id,$name,$nic_macaddr,$status"
        done
}

function do_vnc {
	vmcfg=$(get_cfg_by_id_or_name $1)
	source $vmcfg || error "Can't read file $vmcfg"

	echo $(cat ${rundir}/${id}.host):$id
}

function do_monitor {
        vmcfg=$(get_cfg_by_id_or_name $1)
        source $vmcfg || error "Can't read file $vmcfg"

	socket=$(get_monitor_path ${id})

	if [ -e "${rundir}/${id}.socket" ]
	then
		${cmd_socat} stdio $socket
	else
		warn "No monitor socket available"
		return 1
	fi
}

function do_halt {
        vmcfg=$(get_cfg_by_id_or_name $1)
        source $vmcfg || error "Can't read file $vmcfg"

	if do_status ${id}
	then
		echo "system_powerdown" | do_monitor ${id} >/dev/null

		for i in $(seq 1 ${halt_timeout})
		do
			debug "still running..."
			if ! do_status ${id}
			then
				echo halted
				rundir_cleanup ${id}
				exit 0
			fi
			sleep 1
		done

		warn "VM with id ${id} halt timeout reached. Kill it"
		do_kill ${id}
	else
		warn "VM not running anymore"
		exit 1
	fi
}

function do_status {
	vmcfg=$(get_cfg_by_id_or_name $1)
	source $vmcfg || error "Can't read file $vmcfg"

	if [ -e "${rundir}/${id}.pid" ]
	then
		pid=$(cat ${rundir}/${id}.pid)
		args=$(cat ${rundir}/${id}.args)
	else
		return 1
	fi

	
	if ps -p ${pid} -f  --no-heading >/dev/null
	then
		return 0
	else
		return 1
	fi
	
}

function do_migrate {
	vmcfg=$(get_cfg_by_id_or_name $1)
	target=$2

        source $vmcfg || error "Can't read file $vmcfg"

	if do_status ${id}
	then
		${cmd_ssh} ${target} ${cmd_mit_kvm} incoming ${id} || error "error starting incoming on ${target}" &
		sleep 2 &&
		echo "migrate tcp://${target}:$(calc_migration_port ${id})" |  do_monitor ${id}
		sleep 2 &&
		echo "info migration"  | do_monitor ${id} 

	else
		error "not running here"
	fi
}

function do_incoming {
	vmcfg=$(get_cfg_by_id_or_name $1)
        source $vmcfg || error "Can't read file $vmcfg"

	do_start ${id} "-incoming tcp://0:$(calc_migration_port ${id})"
}

function do_kill {
        vmcfg=$(get_cfg_by_id_or_name $1)
        source $vmcfg || error "Can't read file $vmcfg"
		        
	pid=$(cat ${rundir}/${id}.pid)
	args=$(cat ${rundir}/${id}.args)

	if [ -n "${pid}" ]
	then
		if ps -f -p ${pid} | grep -- "${args}" >/dev/null
		then 
			kill ${pid}
			sleep 5
			if ! ps -p ${pid} >/dev/null
			then
				rundir_cleanup ${id}
			else
				error "PID ${pid} not gone away"
			fi
		else
			error "PID ${pid} is not started with the same arguments. Args should be: ${args}"
		fi
	else
		error "No PID with number ${pid}"
	fi
}

function do_config {
	vmcfg=$(get_cfg_by_id_or_name $1)
	${cmd_editor} ${vmcfg}
}
			
function do_help() {

cat <<EOF

Usage:
$0 <command> <id|name>

Where <command>
	list  - list available images
	config - edit configfile
	start - start a machine
	halt - try to gracefully halt a machine
	vnc - show vnc port
	monitor - connect to qemu monitor
	kill - kill machine immediatly
	status - running or not

Version: $version

EOF

}

case "$1" in 
	start)
		debug "Start ..."
		do_start $2;;
	list)
		debug "List ..."
		do_list | ${cmd_list_sort} ;;
	vnc)
		debug "Vnc ..."
		do_vnc $2 ;;
	monitor)
		debug "Monitor ..."
		do_monitor $2 ;;
	halt)
		debug "Halt ..."
		do_halt $2 ;;
	kill)
		debug "Kill ..."
		do_kill $2
		;;
	status)
		debug "Status ..."
		if do_status $2
		then
			echo running
			exit 0
		else
			echo stopped
			exit 1
		fi
		;;
	config)
		debug "Config ..."
		do_config $2
		;;
	incoming)
		debug "Incoming..."
		do_incoming $2
		;;
	migrate)
		debug "Migrate..."
		do_migrate $2 $3
		;;
	*)	
		do_help
esac