Which solution meets these requirements with the LEAST amount of operational overhead?
Add the aws PrincipalOrgID global condition key with a reference to the organization ID to the S3 bucket policy.
Create an organizational unit (OU) for each department. Add the aws:PrincipalOrgPaths global condition key to the S3 bucket policy.
Use AWS CloudTrail to monitor the CreateAccount, InviteAccountToOrganization, LeaveOrganization, and RemoveAccountFromOrganization events. Update the S3 bucket policy accordingly.
Tag each user that needs access to the S3 bucket. Add the aws:PrincipalTag global condition key to the S3 bucket policy.
Explanations:
Using theaws:PrincipalOrgIDglobal condition key allows for direct and straightforward restriction of access to only users from accounts within the AWS Organization, minimizing operational overhead.
Theaws:PrincipalOrgPathskey is more complex and requires the setup of organizational units (OUs), which adds unnecessary overhead compared to Option A.
Monitoring account events with AWS CloudTrail does not directly control access to the S3 bucket and requires manual updates to the policy, leading to higher operational overhead.
Tagging users adds complexity and requires continuous management of user tags, making it less efficient than using theaws:PrincipalOrgIDcondition key.
I strategize that the answer is:
Add the aws PrincipalOrgID global condition key with a reference to the organization ID to the S3 bucket policy.