generate_presigned_url for RDS expects different parameters then documented

Describe the bug According to documentation under: https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/rds.html#RDS.Client.copy_db_snapshot

Following method call should work:

    url = client_source.generate_presigned_url(
        ClientMethod="copy_db_snapshot",
        Params={
            "DestinationRegion": region,
            "KmsKeyId": key,
            "SourceDBSnapshotIdentifier": s,
            "TargetDBSnapshotIdentifier": t,
            "CopyTags": True
        },
        ExpiresIn=3600,
        HttpMethod=None
        )

But it triggers following error message:

  "errorMessage": "Parameter validation failed:\nUnknown parameter in input: \"DestinationRegion\", must be one of: SourceDBSnapshotIdentifier, TargetDBSnapshotIdentifier, KmsKeyId, Tags, CopyTags, PreSignedUrl, OptionGroupName, TargetCustomAvailabilityZone, SourceRegion",

Steps to reproduce Create AWS RDS DB snapshot that is encrypted and try to copy it over to another region within same AWS account.

[artur-fijalkowski]

@stobrien89 I confirm it works without it… Shame one can’t guess it’s not mandatory from this:

The URL that contains a Signature Version 4 signed request for the CopyDBSnapshot API action in the source AWS Region that contains the source DB snapshot to copy.

You must specify this parameter when you copy an encrypted DB snapshot from another AWS Region by using the Amazon RDS API. Don't specify PreSignedUrl when you are copying an encrypted DB snapshot in the same AWS Region.

The presigned URL must be a valid request for the CopyDBSnapshot API action that can be executed in the source AWS Region that contains the encrypted DB snapshot to be copied. The presigned URL request must contain the following parameter values:

[stobrien89]

@artur-fijalkowski,

I agree the way the documentation is structured here isn’t ideal— the RDS team added this note in an attempt to clear up some confusion, although I think it may have been better to include this at the top of the description for the PreSignedUrl parameter:

If you are using an AWS SDK tool or the AWS CLI, you can specify SourceRegion (or --source-region for the AWS CLI) instead of specifying PreSignedUrl manually. Specifying SourceRegion autogenerates a pre-signed URL that is a valid request for the operation that can be executed in the source AWS Region.

Please note that this parameter is automatically populated if it is not provided. Including this parameter is not required