#!/bin/bash
# os-migrate-instance.sh, ABr, 20141010
# Migrate instance to another host

# Provide usage
function usage {
  echo "Usage: $0 [VM_ID|VM_NAME] [VM_TENANT]"
  exit 1
}

function do_exit {
  rm -f $l_tmp
  exit $1
}

# work file
l_tmp="/tmp/os-migrate-instance.$$"

# check for usage
[[ $# -eq 0 ]] && usage
l_in_vm_id_name="$1"
l_in_vm_tenant="$2"

# get the ID
l_rc=0
if [ "$l_in_vm_tenant" = "" ]; then
  nova show "$l_in_vm_id_name" 2>/dev/null > $l_tmp
  l_rc=$?
else
  nova --os-tenant-name="$l_in_vm_tenant" show "$l_in_vm_id_name" 2>/dev/null > $l_tmp
  l_rc=$?
fi
if [ $l_rc -ne 0 ]; then
  echo -n "Invalid VM ID or name '"
  [[ "$l_in_vm_tenant" != "" ]] && echo -n "$l_in_vm_tenant"
  echo "$l_in_vm_id_name'"
  do_exit 1
fi
#set -x
l_vm_id=$(cat $l_tmp | grep -e "^| id" | cut -d'|' -f 3 | sed -e 's#^ \+##; s#[ \t]*$##')

# get initial state of VM
l_vm_name=$(cat $l_tmp | grep -e "^| name" | cut -d'|' -f 3 | sed -e 's#^ \+##; s#[ \t]*$##')
l_vm_tenant_id=$(cat $l_tmp | grep -e "^| tenant_id" | cut -d'|' -f 3 | sed -e 's#^ \+##; s#[ \t]*$##')
l_vm_state=$(cat $l_tmp | grep -e "^| OS-EXT-STS:vm_state" | cut -d'|' -f 3 | sed -e 's#^ \+##; s#[ \t]*$##')
l_vm_status=`cat "$l_tmp" | grep status | awk '{print $4}'`
l_vm_tenant=$(keystone tenant-get $l_vm_tenant_id | grep -e '  name  ' | cut -d'|' -f 3 | sed -e 's#^ \+##; s#[ \t]*$##')
set +x

# determine what we can do
l_state=0
case "$l_vm_status" in
SHUTOFF)
  # we can migrate
  l_state=0
  ;;
VERIFY_RESIZE)
  # we can verify
  l_state=2
  ;;
RESIZE)
  # we can wait
  l_state=1
  ;;
*)
  # invalid state
  l_rc=2
  ;;
esac
if [ $l_rc -ne 0 ]; then
  echo "$l_vm_tenant:$l_vm_name ($l_vm_id); invalid status ($l_vm_status); cannot migrate"
  do_exit $l_rc
fi

# Migrate the VM to an alternate hypervisor
l_time=$(date +"%Y%d%m-%H:%M")
echo -n "$l_time: Migrate $l_vm_tenant:$l_vm_name ($l_vm_id): "
l_ok=1
if [ $l_state -eq 0 ]; then
  l_ok=0
  nova migrate $l_vm_id && l_ok=1
fi
l_ctr=0
if [ $l_ok -eq 1 ]; then
  nova show $l_vm_id > $l_tmp
  l_vm_status=`cat "$l_tmp" | grep status | awk '{print $4}'`
  while [ "$l_vm_status" = "RESIZE" ]; do
    l_ctr=$(( $l_ctr + 1 ))
    l_modulo=$(( $l_ctr  % 4 ))
    [ $l_modulo -eq 0 ] && echo -n '|'
    [ $l_modulo -eq 1 ] && echo -n '/'
    [ $l_modulo -eq 2 ] && echo -n '-'
    [ $l_modulo -eq 3 ] && echo -n "\\"
    sleep 3
    if nova show $l_vm_id > $l_tmp; then
      l_vm_status=`cat "$l_tmp" | grep status | awk '{print $4}'`
      echo -e -n '\b'
    else
      l_vm_status='foo'
    fi
  done

  # check result
  if [[ "$l_vm_status" != "VERIFY_RESIZE" ]]; then
    echo "FAIL! ($l_vm_status)"
  else
    if nova resize-confirm $l_vm_id; then
      sleep 5
      echo "OK."
    fi
  fi
fi
l_time=$(date +"%Y%d%m-%H:%M")
echo "$l_time: VM status:"
nova show $l_vm_id
do_exit 0