Support importing/updating of S3 bucket policy

[swalmsley11]

Name of the resource

AWS::S3::BucketPolicy

Resource name

No response

Description

Currently, when trying to update the bucket policy via CloudFormation it will causing the error 'The bucket policy already exists on bucket'. In order to make changes, customer needs to delete and reapply policy, which will cause an outage because of this action.

In short, In order to update bucket policy we would need to delete and recreate it.

Other Details

No response

[benbridts]

This is something you run into, if there is an existing bucket policy that is not managed by CloudFormation (or if you have two resources trying to manage the same bucket policy).

Assuming in this case it's the former, this would be solved (and in my opinion solved better) if AWS::S3::BucketPolicy supported Import. General issue: #276

[swalmsley11]

The current use-case is specific to importing an existing bucket policy, so Thank You for the general issue link. I looked over that in my initial search.

[sagar794]

Based on the documentation, it seems like AWS::S3::BucketPolicy is now a resource that can be imported into CloudFormation. I haven't tested this myself nor have I seen any news on this except for the documentation update. Hopefully it works as expected!