Which solution will resolve this issue?
In Account B, create a bucket ACL to allow the user from Account A to access the S3 bucket in Account B.
In Account B, create an object ACL to allow the user from Account A to access all the objects in the S3 bucket in Account B.
In Account B, create a bucket policy to allow the user from Account A to access the S3 bucket in Account B.
In Account B, create a user policy to allow the user from Account A to access the S3 bucket in Account B.
Explanations:
Bucket ACLs (Access Control Lists) are not recommended for cross-account access as they are limited in scope and can be complex to manage. Additionally, bucket ACLs can only grant access to the entire bucket, not specific users in another account.
Object ACLs also grant access on an individual object basis but do not provide a scalable solution for granting access to all objects in a bucket. They are also limited in their ability to manage cross-account permissions effectively.
A bucket policy is the recommended method for granting cross-account access to S3 buckets. It allows you to specify permissions directly on the bucket and can easily include the IAM user from Account A, enabling them to access all objects in the bucket.
User policies are not suitable for granting access to resources in another account. They can only manage permissions for resources within the same account and cannot facilitate cross-account access to an S3 bucket.
As I recall, the answer is:
In Account B, create a bucket policy to allow the user from Account A to access the S3 bucket in Account B.