porting over changes from PR#7837

Author: Liz Baldo

CHANGELOG.md

@@ -11,6 +11,7 @@ The PK of the JOB_KEY_VALUE_ENTRY table will be migrated from INT to BIGINT.
 The Docker registry implementation now correctly handles ECR's support for repository-less image paths.
 
 ### AWS Batch
+* Added support for submitting jobs to AWS Batch queues in different regions. The region is now automatically derived from the `queueArn` runtime attribute, allowing multi-region workflows without additional configuration.
 * Fixed an issue where job failures before all outputs were written would cause delocalization to fail, preventing the upload of return code, stdout, and stderr files needed for debugging.
 * Split the option to tag resources between AWS Batch jobs vs. EC2 and EBS volumes hardware
 * Moved the option to tag job resources from runtime attributes to backend config.

supportedBackends/aws/src/main/scala/cromwell/backend/impl/aws/AwsBatchJob.scala

@@ -110,15 +110,20 @@ final case class AwsBatchJob(
     case prefix => if (prefix.endsWith("/")) prefix else s"$prefix/"
   }
 
+  // Region derived from queueArn, with configRegion as fallback
+  // This allows jobs to be submitted to queues in different regions
+  lazy val batchRegion: Option[Region] = regionFromArn(runtimeAttributes.queueArn).orElse(configRegion)
+
   lazy val batchClient: BatchClient = {
     val builder = BatchClient.builder()
-    configureClient(builder, optAwsAuthMode, configRegion)
+    configureClient(builder, optAwsAuthMode, batchRegion)
   }
+  // CloudWatch logs are in the same region as the Batch job
   lazy val cloudWatchLogsClient: CloudWatchLogsClient = {
     val builder = CloudWatchLogsClient.builder()
-    configureClient(builder, optAwsAuthMode, configRegion)
+    configureClient(builder, optAwsAuthMode, batchRegion)
   }
-
+  // S3 client uses the config region (S3 is region-agnostic for access)
   lazy val s3Client: S3Client = {
     val builder = S3Client.builder()
     configureClient(builder, optAwsAuthMode, configRegion)

supportedBackends/aws/src/main/scala/cromwell/backend/impl/aws/package.scala

@@ -14,6 +14,24 @@ package object aws {
 
   type Aws[F[_], A] = ReaderT[F, AwsBatchAttributes, A]
 
+  /**
+   * Extracts the AWS region from an ARN string.
+   * ARN format: arn:partition:service:region:account-id:resource
+   * For example: arn:aws:batch:eu-west-2:123456789012:job-queue/my-queue
+   *
+   * @param arn The ARN string to extract the region from
+   * @return Some(Region) if a valid region is found, None otherwise
+   */
+  def regionFromArn(arn: String): Option[Region] =
+    Option(arn).flatMap { a =>
+      val parts = a.split(":")
+      if (parts.length >= 4 && parts(3).nonEmpty) {
+        Some(Region.of(parts(3)))
+      } else {
+        None
+      }
+    }
+
   def sanitize(name: String): String =
     // Up to 128 letters (uppercase and lowercase), numbers, hyphens, and underscores are allowed.
     // We'll replace all invalid characters with an underscore