feat: expose lambda_architectures and forwarder_use_cache_bucket (#109)

* feat(datadog-lambda-forwarder): expose lambda_architectures and forwarder_use_cache_bucket

Pass lambda_architectures and forwarder_use_cache_bucket through to the
upstream cloudposse/datadog-lambda-forwarder/aws module and add matching
wrapper variables.

Setting lambda_architectures to ["arm64"] lets consumers run Datadog
Forwarder 5.x artifacts, whose native dependencies are built for arm64 and
fail on x86_64 with errors such as "No module named 'ujson'" during cold
start. lambda_runtime was already wired through.

forwarder_use_cache_bucket defaults to true to preserve upstream behavior
while letting a stack opt out of creating or using the cache bucket.

* fix(datadog-lambda-forwarder): restore datadog provider constraint in docs and validate lambda_architectures

Restore the Providers table to the declared constraint (>= 3.3.0, < 4.0.0)
in both READMEs; a prior doc regeneration had pinned it to a concrete local
version (3.91.0), making the generated docs non-deterministic.

Add a validation block to lambda_architectures so plan-time input is limited
to "x86_64" and/or "arm64", while allowing the null default to pass through
to the upstream module unchanged.

Author: johncblandii

README.md

@@ -64,11 +64,13 @@ module "datadog_lambda_forwarder" {
   forwarder_rds_enabled                 = var.forwarder_rds_enabled
   forwarder_rds_filter_pattern          = var.forwarder_rds_filter_pattern
   forwarder_rds_layers                  = var.forwarder_rds_layers
+  forwarder_use_cache_bucket            = var.forwarder_use_cache_bucket
   forwarder_vpc_logs_artifact_url       = var.forwarder_vpc_logs_artifact_url
   forwarder_vpc_logs_enabled            = var.forwarder_vpc_logs_enabled
   forwarder_vpc_logs_layers             = var.forwarder_vpc_logs_layers
   forwarder_vpclogs_filter_pattern      = var.forwarder_vpclogs_filter_pattern
   kms_key_id                            = var.kms_key_id
+  lambda_architectures                  = var.lambda_architectures
   lambda_policy_source_json             = var.lambda_policy_source_json
   lambda_reserved_concurrent_executions = var.lambda_reserved_concurrent_executions
   lambda_runtime                        = var.lambda_runtime

src/README.md

@@ -28,6 +28,17 @@ variable "lambda_runtime" {
   default     = "python3.11"
 }
 
+variable "lambda_architectures" {
+  type        = list(string)
+  description = "Instruction set architecture for the Datadog Lambda function. Valid values are [\"x86_64\"] and [\"arm64\"]. Set to [\"arm64\"] when using Datadog Forwarder 5.x artifacts."
+  default     = null
+
+  validation {
+    condition     = var.lambda_architectures == null ? true : alltrue([for a in var.lambda_architectures : contains(["x86_64", "arm64"], a)])
+    error_message = "lambda_architectures must be null or a list containing only \"x86_64\" and/or \"arm64\"."
+  }
+}
+
 variable "tracing_config_mode" {
   type        = string
   description = "Can be either PassThrough or Active. If PassThrough, Lambda will only trace the request from an upstream service if it contains a tracing header with 'sampled=1'. If Active, Lambda will respect any tracing header it receives from an upstream service"
@@ -82,6 +93,12 @@ variable "forwarder_log_retention_days" {
   default     = 14
 }
 
+variable "forwarder_use_cache_bucket" {
+  type        = bool
+  description = "Flag to enable or disable the cache bucket for lambda tags and failed events. See https://docs.datadoghq.com/logs/guide/forwarder/?tab=cloudformation#upgrade-an-older-version-to-31060. Recommended for forwarder versions 3.106 and higher."
+  default     = true
+}
+
 variable "kms_key_id" {
   type        = string
   description = "Optional KMS key ID to encrypt Datadog Lambda function logs"