Dynamic bucket lookup and cross region copy object support.

s3client.scala

import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider
import software.amazon.awssdk.regions.Region
import software.amazon.awssdk.services.s3.S3Client
import software.amazon.awssdk.services.s3.model.{S3Exception,CopyObjectRequest,CopyObjectResponse,HeadBucketRequest}
import scala.util.{Try,Success,Failure}


/**
  Cross region copy object example with region code discovery for a bucket.
**/
val defaultRegion = Region.US_WEST_2

val creds = ProfileCredentialsProvider.builder().build()
// I'd probably do a warm up where I collected all configs and iterated over them, creating a client for a new region when not found.
val clients = Map(
    Region.US_WEST_2 -> S3Client.builder().region(Region.US_WEST_2).credentialsProvider(creds).build(),
    Region.US_EAST_1 -> S3Client.builder().region(Region.US_EAST_1).credentialsProvider(creds).build(),
)

val defaultS3 = clients(Region.US_WEST_2)

val fromBucket = "source-bucket"
val sourceKey = "s3-testing/testfile.txt"
val toBucket = "destination-bucket"
val destKey = "s3-testing/testfile-copied.txt"

 val copyReq = CopyObjectRequest.builder()
             .sourceBucket(fromBucket)
             .sourceKey(sourceKey)
             .destinationBucket(toBucket)
             .destinationKey(destKey)
             .build()

val regionReq = HeadBucketRequest.builder().bucket(toBucket).build()

// feel like there ought to be a constant somewhere for the header region value
// so wouldn't have to use string literals.
val region = Try(defaultS3.headBucket(regionReq)) match {
    Success(r) => r.sdkHttpResponse().headers().get("x-amz-bucket-region").get(0) 
    Failure(e) => e.asInstanceOf[S3Exception].awsErrorDetails().sdkHttpResponse().headers().get("x-amz-bucket-region").get(0)
}

val resp = clients(Region.of(region)).copyObject(copyReq)

// handle response