[SVLS-7075] append datadog layer instead of prepend (#37)

Author: ava-silver

main.tf

@@ -63,7 +63,7 @@ locals {
   datadog_lambda_layer_version = lookup(local.runtime_base_layer_version_map, local.runtime_base, "")
 
   datadog_account_id      = (data.aws_partition.current.partition == "aws-us-gov") ? "002406178527" : "464622532012"
-  datadog_layer_name_base = "arn:${data.aws_partition.current.partition}:lambda:${data.aws_region.current.name}:${local.datadog_account_id}:layer"
+  datadog_layer_name_base = "arn:${data.aws_partition.current.partition}:lambda:${data.aws_region.current.region}:${local.datadog_account_id}:layer"
   datadog_layer_suffix    = lookup(local.architecture_layer_suffix_map, var.architectures[0])
 
   environment_variables = {
@@ -174,9 +174,9 @@ resource "aws_lambda_function" "this" {
   # Datadog layers are defined in single element lists
   # This allows for runtimes where a lambda layer is not needed by concatenating an empty list
   layers = concat(
-    local.layers.extension,
+    var.layers,
     local.layers.lambda,
-    var.layers
+    local.layers.extension,
   )
 
   dynamic "logging_config" {