Delete Old Files on Amazon AWS S3

If you have a script to automatically back up to Amazon S3 from your server, it is good to limit the age of stored backups.

This bash script allows you to use s3cmd to do just that. You specify the bucket to process and the age os files to retain.

Important: You must first install and configure s3cmd.

#!/bin/bash

usage (){
  echo " "
  echo Usage: s3-del-old "bucketname" "time"
  echo Example: s3-del-old \"mybucket\" \"30 days\"
  echo " "
  echo "Do not include a leading slash in bucketname."
  echo " "
}

# if incorrect # parameters, show usage
if [ $# -lt 2 ]; then
  usage
  exit 2
elif [ $# -gt 2 ]; then
  usage
  exit 2
fi

# don't allow leading slash in bucketname
firstchar=${1:0:1}
if [ $firstchar = "/" ]; then
  echo "ERROR: Do not start bucketname with a slash."
  usage
exit 2
fi

# don't allow "s3:" in beginning of filename
teststring=${1:0:3}
teststring=${teststring,,}
if [ $teststring = "s3:" ]; then
  echo "ERROR: Do not start bucketname with \"s3:\""
  usage
exit 2
fi

# transform first parameter into fully formed s3 bucket parameter with trailing slash star
target='s3://'${1%/}'/*'

s3cmd ls $target | while read -r line;
do
  create_date=`echo $line | awk '{print $1,$2}'`
  create_date_unixtime=`date -d"$create_date" +%s`
  older_than_unixtime=`date -d"-$2" +%s`
  if [[ $create_date_unixtime -lt $older_than_unixtime ]]
  then
    filename=`echo $line|awk '{print $4}'`
    if [[ $filename != "" ]]
    then
      echo deleting $filename $create_date
      s3cmd del $filename
    fi
  fi
done;