Add support for AWS EBS Snapshot Lock mode

[ruimarinho]

This pull request introduces support for AWS EBS Snapshot Lock to protect Amazon EBS snapshots against accidental or malicious deletions, or to store them in WORM (Write-Once-Read-Many) format for a specific duration.

While a snapshot is locked, as long as it is out of the cool-off period, it can't be deleted by any user, regardless of their IAM permissions.

Overview of changes

• Added new command-line arguments for AWS snapshot lock mode, lock duration, cool-off period, and expiration date. Implemented mutual exclusivity checks for lock duration and expiration date, as per AWS requirements.
  • --aws-snapshot-lock-mode
  • --aws-snapshot-lock-duration
  • --aws-snapshot-lock-cool-off-period
  • --aws-snapshot-lock-expiration-date
• Added new provider-specific snapshot_lock_mode to backup metadata json.
• Implemented checks to prevent attempting to deleted a locked snapshot until it becomes expired.

If the approach looks good, I will start working on documentation next.

Closes #972.

[diogotorres97]

That is a great feature that we were waiting for! Already tested it in an AWS EC2 instance with barman installed and it is working as expected!

[diogotorres97]

ping