provisioned concurrency

Author: Karthikeyannhs

infrastructure/modules/lambda/lambda.tf

@@ -37,3 +37,17 @@ resource "aws_lambda_function" "eligibility_signposting_lambda" {
     mode = "Active"
   }
 }
+
+# provisioned concurrency - number of pre-warmed lambda containers
+resource "aws_lambda_alias" "campaign_alias" {
+  name             = "live"
+  function_name    = aws_lambda_function.eligibility_signposting_lambda.function_name
+  function_version = aws_lambda_function.eligibility_signposting_lambda.version
+}
+
+resource "aws_lambda_provisioned_concurrency_config" "campaign_pc" {
+  count                             = var.environment == "prod" ? 1 : 0
+  function_name                     = aws_lambda_function.eligibility_signposting_lambda.function_name
+  qualifier                         = aws_lambda_alias.campaign_alias.name
+  provisioned_concurrent_executions = var.provisioned_concurrency_count
+}

infrastructure/modules/lambda/variables.tf

@@ -52,3 +52,8 @@ variable "enable_xray_patching"{
   description = "flag to enable xray tracing, which puts an entry for dynamodb, s3 and firehose in trace map"
   type        = string
 }
+
+variable "provisioned_concurrency_count" {
+  description = "Number of prewarmed Lambda instances"
+  type        = number
+}

infrastructure/stacks/api-layer/lambda.tf

@@ -26,4 +26,5 @@ module "eligibility_signposting_lambda_function" {
   log_level                       = "INFO"
   enable_xray_patching            = "true"
   stack_name                      = local.stack_name
+  provisioned_concurrency_count   = 5
 }