Yunfei Jiang

> > @patrickdillon do you know who could help review the required permissions in the docs? I suspect that those not listed in the [Installer](https://github.com/openshift/installer/blob/master/pkg/asset/installconfig/aws/permissions.go) might be needed by some...

> HeadBucket is an action--not a required permission--which the installer is testing to see if the creds have sufficient permissions to perform. According [to this](https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadBucket.html) `s3:ListBucket` is the required permission...

/lgtm