AWSTemplateFormatVersion: '2010-09-09'
Description: AWS SSM Document to resize EBS volumes and grow the filesystem on them.
Parameters:
  VolumeSize: 
    Type: Number
    Description: The Size in GB of the Instance Volume. 
    Default: 50
Resources:
 ResizeEBSVolumeDoc:
    Type: AWS::SSM::Document
    Properties:
      DocumentFormat: YAML
      DocumentType: Command
      Name: Resize-EBS-Volume
      TargetType: /AWS::EC2::Instance
      Content:
        schemaVersion: "2.2"
        description: "Command document to resize EBS volume."
        parameters:
          VolumeSize:
            type: String
            description: "Size in GB to grow the volume"
            default: !Sub "${VolumeSize}"
            allowedPattern: ^(?:1(?:[0-5][0-9]{0,3}|[7-9][0-9]{0,2}|6(?:[0-2]{0,3}|[4-9][0-9]?|3(?:[0-7][0-9]?|8[0-4]?|9)?)?)?|[2-9][0-9]{0,3})$
        mainSteps:
        - action: "aws:runShellScript"
          name: "resizeVolume"
          inputs:
            runCommand:
            - "date"
            - "SIZE_PARAM={{VolumeSize}}"
            - "export SIZE=${SIZE_PARAM:-20}"
            - "export INSTANCEID=$(curl http://169.254.169.254/latest/meta-data/instance-id)"
            - "echo \"INSTANCEID: $INSTANCEID\""
            - "export AWS_REGION=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed 's/\\(.*\\)[a-z]/\\1/')"
            - "echo \"AWS_REGION: $AWS_REGION\""
            - "export AWS_DEFAULT_REGION=$AWS_REGION"
            - "export VOLUMEID=$(aws ec2 describe-instances --instance-id $INSTANCEID --query 'Reservations[0].Instances[0].BlockDeviceMappings[0].Ebs.VolumeId' --output text)"
            - "echo \"VOLUMEID: $VOLUMEID\""
            - "aws ec2 modify-volume --volume-id $VOLUMEID --size $SIZE"
            - "while [ \"$(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"
        - action: "aws:runShellScript"
          name: "extendFileSystem"
          inputs:
            runCommand:
            - "if [[ -e \"/dev/xvda\" && $(readlink -f /dev/xvda) = \"/dev/xvda\" ]]; then"
            - "  growpart /dev/xvda 1"
            - "  STR=$(cat /etc/os-release)"
            - "  SUB='VERSION_ID=\"2\"'"
            - "  if [[ \"$STR\" == *\"$SUB\"* ]]; then"
            - "    xfs_growfs -d /"
            - "  else"
            - "    resize2fs /dev/xvda1"
            - "  fi"
            - "else"
            - "  growpart /dev/nvme0n1 1"
            - "  STR=$(cat /etc/os-release)"
            - "  SUB='VERSION_ID=\"2\"'"
            - "  if [[ \"$STR\" == *\"$SUB\"* ]]; then"
            - "    xfs_growfs -d /"
            - "  else"
            - "    resize2fs /dev/nvme0n1p1"
            - "  fi"
            - "fi"