Create EC2 Consistent Backup

ec2-consistentbackup.sh

#!/bin/bash

# ec2-consistentbackup --description='My First backup' --tags="user=asvignesh;"
# This script freezes all EXT4 and XFS Filesystem running on Linux EC2 Instances

description=""
tags=""

for i in "$@"
do
case $i in
    --description=*) description="${i#*=}" ;;
    --tags=*) tags="${i#*=}" ;;
    *) ;;
esac
done

if [[ -z $tags ]]; then
  tags_spec=""
else
  # Input format is name=value;name2=value2
  # Output format is {Key=name,Value=value},{Key=name2,Value=value2}
  new_tags=$( echo $tags | perl -p -e 's/(.*?)=(.*?)(;|$)/{Key=\1,Value=\2},/g; s/,$//' )
  tags_spec="ResourceType=snapshot,Tags=[$new_tags]"
fi


# Unfreeze file systems
function unfreeze() {
  for target in $(findmnt -nlo TARGET -t ext4,xfs); {
    if [[ "$target" != "/"  ]]; then
      fsfreeze --unfreeze "$target";
    fi
  }
}

function warn_and_unfreeze() {
  # If there was any problem, make sure to unfreeze the filesystems before quitting!
  errorCode=$?
  if [ $errorCode -ne 0 ]; then
    unfreeze
    echo -e "ec2-consistent-snapshot exited with an error: $snapshot_output\n$vol_output"
    exit $errorCode
  fi
}

# Make sure to unfreeze if we are done, but but also if there was an error or if we are interrupted
trap warn_and_unfreeze SIGINT ERR

# Sync data to disk
sync

{
  # Find the volumes for the instance
  instance=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
  # Get the Availability Zone, like "us-east-1b"
  az=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone)
  # Trim off the last character of the AZ, so "us-east-1b" becomes "us-east-1"
  region=${az::-1}

  volumes=$(
    aws ec2 describe-instance-attribute --instance-id $instance \
                                        --attribute blockDeviceMapping \
                                        --output text \
                                        --query BlockDeviceMappings[*].Ebs.VolumeId \
                                        --region $region
  )


  # Find the mounted EXT4 and XFS partitions and freeze them
  # To avoid hanging the machine in unrecoverable way, don't freeze "/".
  for target in $(findmnt -nlo TARGET -t ext4,xfs); {
    if [[ "$target" != "/"  ]]; then
      fsfreeze --freeze "$target";
    fi
  }

  snapshot_output=""

  # Create snapshots for the current instance
  # Be sure you have an Role attached to the instance
  #  and that the role has permission to make snapshots.
  for volume in $(echo $volumes | tr " " "\n"); {
    vol_output=$(
      aws ec2 create-snapshot --volume-id $volume \
                              --description "$description" \
                              --region $region \
                              --tag-specifications "$tags_spec" 2>&1
    )
    snapshot_output="$snapshot_output\n$vol_output";
  }

  unfreeze
}

exit 0;

IAM Role.json

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "1",
            "Effect": "Allow",
            "Action": [
                "ec2:CreateSnapshot",
                "ec2:CreateTags",
                "ec2:DescribeInstanceAttribute"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}