I\'ve been trying for past couple of hours to setup a transfer from S3 to my google storage bucket.
The error that i keep getting, when creating the transfer is: \"I
I'm one of the devs on Transfer Service.
You'll need to add "s3:GetBucketLocation" to your permissions.
It would be preferable if the error you received was more specifically about your ACLs, however, rather than an invalid key. I'll look into that.
EDIT: Adding more info to this post. There is documentation which lists this requirement: https://cloud.google.com/storage/transfer/
Here's a quote from the section on "Configuring Access":
"If your source data is an Amazon S3 bucket, then set up an AWS Identity and Access Management (IAM) user so that you give the user the ability to list the Amazon S3 bucket, get the location of the bucket, and read the objects in the bucket." [Emphasis mine.]
EDIT2: Much of the information provided in this answer could be useful for others, so it will remain here, but John's answer actually got to the bottom of OP's issue.