Which solution will meet these requirements?
Use a role-based approach by creating an IAM role with an inline permissions policy that allows access to the secret. Update the IAM principals in the role trust policy as required.
Deploy a VPC endpoint for Secrets Manager. Create and attach an endpoint policy that specifies the IAM principals that are allowed to access the secret. Update the list of IAM principals as required.
Use a tag-based approach by attaching a resource policy to the secret. Apply tags to the secret and the IAM principals. Use the aws:PrincipalTag and aws:ResourceTag IAM condition keys to control access.
Use a deny-by-default approach by using IAM policies to deny access to the secret explicitly. Attach the policies to an IAM group. Add all IAM principals to the IAM group. Remove principals from the group when they need access. Add the principals to the group again when access is no longer allowed.
Explanations:
While using a role-based approach allows some flexibility, it requires frequent updates to the role trust policy to add or remove IAM principals. This may not scale well and can lead to administrative overhead when the list of principals changes frequently.
Deploying a VPC endpoint with an endpoint policy does not provide the necessary flexibility. The endpoint policy must be updated every time IAM principals need access, which can be cumbersome and does not scale well with frequent changes.
Using a tag-based approach allows for dynamic management of access by attaching resource tags to the secret and using tags on IAM principals. This method leverages theaws:PrincipalTagandaws:ResourceTagcondition keys, allowing for scalable and flexible access control without needing to modify IAM policies or roles every time a principal changes.
This deny-by-default approach can be too rigid and may require significant administrative work to manage the IAM group. Adding and removing principals from the group frequently may lead to delays in access or unintended denials, making it less flexible and scalable compared to other options.
I guess:
Use a tag-based approach by attaching a resource policy to the secret. Apply tags to the secret and the IAM principals. Use the aws:PrincipalTag and aws:ResourceTag IAM condition keys to control access.