#!/bin/bash

# Specify the desired volume size in GiB as a command line argument. If not specified, default to 20 GiB.
SIZE=${1:-20}

# Get the ID of the environment host Amazon EC2 instance.
INSTANCEID=$(curl http://169.254.169.254/latest/meta-data/instance-id)
REGION=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/\(.*\)[a-z]/\1/')

# Get the ID of the Amazon EBS volume associated with the instance.
VOLUMEID=$(aws ec2 describe-instances \
  --instance-id $INSTANCEID \
  --query "Reservations[0].Instances[0].BlockDeviceMappings[0].Ebs.VolumeId" \
  --output text \
  --region $REGION)

# Resize the EBS volume.
aws ec2 modify-volume --volume-id $VOLUMEID --size $SIZE

# Wait for the resize to finish.
while [ \
  "$(aws ec2 describe-volumes-modifications \
    --volume-id $VOLUMEID \
    --filters Name=modification-state,Values="optimizing","completed" \
    --query "length(VolumesModifications)"\
    --output text)" != "1" ]; do
sleep 1
done

#Check if we're on an NVMe filesystem
if [[ -e "/dev/xvda" && $(readlink -f /dev/xvda) = "/dev/xvda" ]]
then
  # Rewrite the partition table so that the partition takes up all the space that it can.
  sudo growpart /dev/xvda 1

  # Expand the size of the file system.
  # Check if we're on AL2
  STR=$(cat /etc/os-release)
  SUB="VERSION_ID=\"2\""
  if [[ "$STR" == *"$SUB"* ]]
  then
    sudo xfs_growfs -d /
  else
    sudo resize2fs /dev/xvda1
  fi

else
  # Rewrite the partition table so that the partition takes up all the space that it can.
  sudo growpart /dev/nvme0n1 1

  # Expand the size of the file system.
  # Check if we're on AL2
  STR=$(cat /etc/os-release)
  SUB="VERSION_ID=\"2\""
  if [[ "$STR" == *"$SUB"* ]]
  then
    sudo xfs_growfs -d /
  else
    sudo resize2fs /dev/nvme0n1p1
  fi
fi