EBS Resizing Script

ebs-resize.sh

#!/bin/sh
#
# $ sudo yum install jq
# $ sudo pip install -U awscli
# # sh ./ebs-resize.sh -d /dev/xvdf -v ebs-volume-name
#

usage() {
  echo "Usage: $0 -d device-name -v ebs-volume-name" 1>&2
  exit 1
}

while getopts d:v:h OPT
do
  case $OPT in
    'd')
      DEVICE_NAME=$OPTARG
      ;;
    'v')
      VOLUME_NAME=$OPTARG
      ;;
    'h')
      usage
      ;;
    \?)
      usage
      ;;
  esac
done

shift $((OPTIND - 1))

if test ${#DEVICE_NAME} -eq 0 -o ${#VOLUME_NAME} -eq 0; then
  usage
fi

df -k $DEVICE_NAME 1> /dev/null
if test "$?" -ne 0; then
  echo "$DEVICE_NAME is not found."
  exit 1
fi

export THRESHOLD_PERCENT=95
export EXPAND_RATE=1.25
export USED_PERCENT=`df -k $DEVICE_NAME | grep -v Filesystem | awk '{print $5}' | awk -F% '{print $1}'`
export CURRENT_SIZE=`df -k $DEVICE_NAME | grep -v Filesystem | awk '{print $2}'`
export NEW_SIZE=`echo "scale=0; $CURRENT_SIZE * $EXPAND_RATE / 1024 / 1024 + 1" | bc -l`
export AWS_DEFAULT_REGION=`curl --silent http://169.254.169.254/latest/meta-data/placement/availability-zone | sed -e 's/.$//g'`
export INSTANCE_ID=`curl --silent http://169.254.169.254/latest/meta-data/instance-id`
export VOLUME_ID=`aws ec2 describe-volumes --filter "Name=attachment.instance-id,Values=$INSTANCE_ID" "Name=tag:Name,Values=$VOLUME_NAME" |  jq -r '.Volumes[].VolumeId'`

if test ${#VOLUME_ID} -eq 0; then
  echo "$VOLUME_NAME is not found."
  exit 1
fi

if test $USED_PERCENT -ge $THRESHOLD_PERCENT; then
  aws ec2 modify-volume --volume-id $VOLUME_ID --size $NEW_SIZE
  sleep 30
  /sbin/resize2fs $DEVICE_NAME
fi

exit 0