How can we enable Amazon S3 replication modification sync in terraform?

Question

I am working on an Amazon S3 replication using terraform . I want to enable rule "Repilcate modification sync" but I don't think so it is defined in terraform .

Right now my code looks :

replication_configuration {
    role = "${aws_iam_role.source_replication.arn}"

    rules {
      id     = "${local.replication_name}"
      status = "Enabled"
      prefix = "${var.replicate_prefix}"

      destination {
        bucket        = "${local.dest_bucket_arn}"
        storage_class = "STANDARD"

        access_control_translation = {
          owner = "Destination"
        }

        account_id = "${data.aws_caller_identity.dest.account_id}"
      }

      source_selection_criteria {
        replica_modifications {
          Status = "Enabled"
        }
      }
    }
  }

It gives an error :

Error: Unsupported block type

  on s3_bucket.tf line 61, in resource "aws_s3_bucket" "bucket":
  61:         replica_modifications {

Blocks of type "replica_modifications" are not expected here.

The rules which I have to enable looks like this in console.

With AWS CLI in terraform , I am not sure how can I use variables like destination ${local.dest_bucket_arn} and ${aws_iam_role.source_replication.arn} in my son file which I am calling.

resource "null_resource" "awsrepl" {
  # ...

  provisioner "local-exec" {
    command = "aws s3api put-bucket-replication --replication-configuration templatefile://replication_source.json --bucket ${var.bucket_name}"
    
  }
} 

replication_source.json looks like :

{
    "Rules": [
        {
            "Status": "Enabled",
            "DeleteMarkerReplication": { "Status": "Enabled" },
            "SourceSelectionCriteria": {
                "ReplicaModifications":{
                    "Status": "Enabled"
                }
            },
            "Destination": {
                "Bucket": "${local.dest_bucket_arn}"
            },
            "Priority": 1
        }
    ],
    "Role": "${aws_iam_role.source_replication.arn}"
}

Answer 1

You are correct. It is not yet supported, but there is a GitHub issue for that already:

• Amazon S3 Two-way Replication via Replica Modification Sync

By the way, Delete marker replication is also not supported.

Your options are to either do it manually after you deploy your bucket, or use local-exec to run AWS CLI to do it, or aws_lambda_invocation.