#!/bin/sh
### BEGIN INIT INFO
# Provides:          kvm-manage
# Required-Start:    kvm $local_fs $remote_fs $syslog $named $network $time
# Required-Stop:     $local_fs $remote_fs $syslog $named $network
# Default-Start:     2
# Default-Stop:      0 1 6
# Short-Description: KVM-management init script
# Description:       This script does a controlled start and stop of kvm instances
### END INIT INFO
 
# kvm-manage - v1.90
#
# GPLv2: please have a look at the license text, which should have been
# shipped with your distribution.
# 
# written by Christian Roessner <christian@roessner-net.com>
#
# Script to manage kvm instances, if libvirt is not applicable
#
# Changes:
#   2008-12-13:
#     - Introduces pgrep routine
#     - Implemeted restart()
#     - Some more friendly output for start() and stop()
#     - Fixes double-stop() in finish()
#     - Check for required helper tools
#     - Combine monitor feature with minicom, is available
#   2008-12-14:
#     - Most parts have been rewritten to try to clean up the code
#     - no more need for the pidfile-paramter in the config files
#     - Clean difference between the kvm and the vdekvm pids
#   2008-12-21:
#     - Detect, if a guest uses kvm or vdekvm-wrapper
#   2008-12-22:
#     - Implemented a destroy() option and modified vdekvm-wrapper
#       detection.
#     - Stop guests that do not have KXX symlinks in rc.
#   2008-12-23:
#     - Added RC_DIR and INST_DIR options.
#     - No more need to wrap run() around the (vde)kvm-commands.
#   2008-12-30: (Thanks to Urs)
#     - Replaces the monitor option from pty to telnet
#   2009-01-08:
#     - Bugfix: If there are no K* or S* files in RC_DIR, skip
#   2009-01-24:
#     - sysvinit block included
#   2010-06-14:
#     - Changing telnet to unix socket socat command
#
# Download: http://www.roessner-net.com/kvm-manage

# How long to wait for starting the next guest
TIME_TO_WAIT=40

# Path to kvm instance scripts
INST_DIR="/etc/kvm/instances"

# Where to store (S)tart and (K)ill symlinks?
RC_DIR="/etc/kvm/rc"
VAR_RUN_DIR="/var/run/kvm"

LOG_CMD="/usr/bin/logger"
AWK_CMD="/usr/bin/awk"
SOCAT_CMD="/usr/bin/socat"

LOG_OPTS="-i -t kvm-manage -p local0.info"

### Do not change things below ###

get_kvm_pid() {
   ps -o pid=,args= -C kvm | grep -- "-name $1 " | $AWK_CMD '{ print $1; }'
}

get_vdekvm_pid() {
   ps -o pid=,args= -C vdekvm | grep -- "-name $1 " | $AWK_CMD '{ print $1; }'
}

get_pidline() {
  ps -o pid=,args= -C kvm | grep -- "-name $1 "
}

get_kvm_names() {
  found=0
  for param in $(ps -o args= -C kvm); do
    if [ $found = 0 ]; then
      if [ "$param" = "-name" ]; then
        found=1
      fi
    else
      list="$list $param"
      found=0
    fi
  done
  echo $list
}

do_stop() {
  echo "Stopping VM: $1"
  pidline=$(get_pidline $1)
  if test -n "$pidline"; then
    var1=${pidline#*-monitor*}
    instance_sock=$(echo $var1 | cut -d " " -f 1 | cut -d "," -f1 | cut -d ":" -f2)
    $LOG_CMD $LOG_OPTS "Shutting down VM($1) on monitor $instance_sock"
    echo "system_powerdown" | $SOCAT_CMD - $instance_sock > /dev/null 2>&1
    # Waiting for the guest to terminate
    for timer in $(seq 1 40); do
      pid=$(get_kvm_pid $1)
      if test -z "$pid"; then
        $LOG_CMD $LOG_OPTS -s "VM($1) shutdown complete"
        break
      fi
      sleep 5
    done
    # Error! We kill the guest
    if [ $timer -eq 40 ]; then
      # Try to save a screendump
      echo "screendump /tmp/kvm-$pid.ppm" | $SOCAT_CMD - $instance_sock > /dev/null 2>&1
      sleep 3
      kill -TERM $pid > /dev/null 2>&1
      $LOG_CMD $LOG_OPTS -s "VM($1) killed!"
    fi
  fi
  vdepid=$(get_vdekvm_pid $1)
  if test -n $vdepid; then
    kill -TERM $vdepid > /dev/null 2>&1
  fi
}

destroy() {
  pid=$(get_kvm_pid $1)
  if test -n "$pid"; then
    kill -TERM $pid > /dev/null 2>&1
  fi
  vdepid=$(get_vdekvm_pid $1)
  if test -n "$vdepid"; then
    kill -TERM $vdepid > /dev/null 2>&1
  fi
}

error() {
  echo $1
  exit 1
}

# Check that all required components are available
test -x $AWK_CMD || error "$AWK_CMD required!"
test -x $LOG_CMD || error "$LOG_CMD required!"
test -x $SOCAT_CMD || error "$SOCAT_CMD required!"
# Create missing folders
test -d $INST_DIR || mkdir -p $INST_DIR
test -d $RC_DIR || mkdir -p $RC_DIR
test -d $VAR_RUN_DIR || mkdir -p $VAR_RUN_DIR

case "$1" in
  start)
    if test -z "$2"; then
      echo "Starting VMs in background"
      (
        for service in $RC_DIR/S*; do
          test -r $service || continue
          base=$(basename $service)
          name=${base#*[SK][0-9][0-9]}
          if test -z "$(get_kvm_pid $name)"; then
            $LOG_CMD $LOG_OPTS "Starting VM($name)"
            . $service
            sleep $TIME_TO_WAIT
          fi
        done
      )&
    else
      name=$(basename $2)
      if test -n "$(get_kvm_pid $name)"; then
        error "Instance already running!"
      else
        echo "Starting VM: $name"
        if test -r $INST_DIR/$name; then
          . $INST_DIR/$name
        else
          error "$2 does not exist!"
        fi
      fi
    fi
    ;;
  stop)
    if test -z "$2"; then
      for service in $RC_DIR/K*; do
        test -r $service || continue
        base=$(basename $service)
        name=${base#*[SK][0-9][0-9]}
        do_stop $name
      done
      # Do we have any manual started guest running?
      still_running=$(get_kvm_names)
      for vm in $still_running; do
        do_stop $vm
      done
    else
      name=$(basename $2)
      do_stop $name
    fi
    ;;
  monitor)
    if test -z "$2"; then
      error "$0 monitor <guest-script>"
    else
      name=$(basename $2)
      pidline=$(get_pidline $2)
      if test -n "$pidline"; then
        var1=${pidline#*-monitor*}
        ip=$(echo $var1 | cut -d " " -f 1 | cut -d "," -f1 | cut -d ":" -f2)
        port=$(echo $var1 | cut -d " " -f 1 | cut -d "," -f1 | cut -d ":" -f3)
        echo "use telnet to monitor VM $name at: $ip:$port"
      fi
    fi
    ;;
  list)
    echo "Currently running VMs:"
    get_kvm_names
    ;;
  restart)
    if test -z "$2"; then
      $0 stop && $0 start
    else
      echo "Restarting VM: $2"
      $0 stop $2 && $0 start $2
    fi
    ;;
  destroy)
    if test -z "$2"; then
      error "$0 destroy <guest-script>"
    else
      name=$(basename $2)
      echo "Destroying VM: $name"
      destroy $name
    fi
    ;;
  *)
    echo "$0 {start|stop|restart|destroy <guest-script>|monitor <guest-script>|list}"
    ;;
esac

exit 0

# vim: ts=2 sw=2 expandtab