https://www.linuxtutorial.co.uk/automate-ebs-volume-backups-bash/

https://github.com/colinbjohnson/aws-missing-tools/tree/master/ec2-automate-backup

https://simplyopensource.blogspot.tw/2014/04/script-to-create-daily-ami-of-aws.html

https://simplyopensource.blogspot.tw/2016/02/script-to-delete-ami-with-attached.html

https://www.flynsarmy.com/2015/06/how-to-schedule-daily-rolling-ebs-snapshots/