Expose Endpoints Partition DNSSuffix

[bflad]

Feature description

There does not appear to be an easy method to extract the existing endpoints.Partition DNSSuffix field for the default partitions:

aws-sdk-go/aws/endpoints/defaults.go

Line 82 in f0c3a48

DNSSuffix: "amazonaws.com",

aws-sdk-go/aws/endpoints/defaults.go

Line 3520 in f0c3a48

DNSSuffix: "amazonaws.com.cn",

aws-sdk-go/aws/endpoints/defaults.go

Line 4014 in f0c3a48

DNSSuffix: "amazonaws.com",

This information is helpful in building AWS partition agnostic IAM policy documents (https://docs.amazonaws.cn/en_us/aws/latest/userguide/iam.html) and constructing hostnames not available in the default endpoints information such as S3 website endpoints (https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region).

Describe alternatives you've considered

Hardcoding the DNS suffix after performing a regional lookup against AWS China:

if partition, ok := endpoints.PartitionForRegion(endpoints.DefaultPartitions(), region); ok && partition.ID() == endpoints.AwsCnPartitionID {
	return fmt.Sprintf("s3-website.%s.amazonaws.com.cn", region)
}
return fmt.Sprintf("s3-website.%s.amazonaws.com", region)

Additional context

• Fixes website_endpoint and website_domain attributes in Chinese regions hashicorp/terraform-provider-aws#9444
• Wrong S3 bucket website_endpoint and website_domain attributes in China regions hashicorp/terraform-provider-aws#9378
• d/Adds a url_suffix attribute to data_source_aws_partition hashicorp/terraform-provider-aws#5602
• AWS missing "pseudo" parameters hashicorp/terraform-provider-aws#1960

[bflad]

Potential implementation submitted: #2711

[jasdel]

Thanks for creating this feature request @bflad. The DNS suffix is an internal detail of the endpoint resolver's metadata, and we've tried to only expose that data as needed. With that said, in this context, I think it makes sense for DNS suffix to be exposed.

We'll review the PR and get back to you with feedback.

[jasdel]

The change looks good, thanks for taking the time to create the PR. It is merged in and will be included in the SDK's next release.