Make the lambda alert period adjustable (#56)

* Remove lifecycle ignore from lambdas This prevented managing the terraform stack from two different workstations / people * Make the lambda alert period adjustable The metric period for the lambda monitoring alerts should be equal or higher than the trigger period. Otherwise the alerts are not significant. This increases the default to 6 hours and makes it adjustable to suit other needs.
skyscrapers · May 4, 2022 · 614a0c3 · 614a0c3
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diff --git a/README.md b/README.md
@@ -264,27 +264,27 @@ data "aws_iam_policy_document" "rds_replication_key" {
 
 | Name | Version |
 |------|---------|
-| <a name="requirement_terraform"></a> [terraform](#requirement_terraform) | ~> 1.0 |
-| <a name="requirement_aws"></a> [aws](#requirement_aws) | ~> 3.61 |
+| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | ~> 1.0 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | ~> 3.61 |
 
 ### Providers
 
 | Name | Version |
 |------|---------|
-| <a name="provider_archive"></a> [archive](#provider_archive) | n/a |
-| <a name="provider_aws.intermediate"></a> [aws.intermediate](#provider_aws.intermediate) | ~> 3.61 |
-| <a name="provider_aws.source"></a> [aws.source](#provider_aws.source) | ~> 3.61 |
-| <a name="provider_aws.target"></a> [aws.target](#provider_aws.target) | ~> 3.61 |
+| <a name="provider_archive"></a> [archive](#provider\_archive) | n/a |
+| <a name="provider_aws.intermediate"></a> [aws.intermediate](#provider\_aws.intermediate) | ~> 3.61 |
+| <a name="provider_aws.source"></a> [aws.source](#provider\_aws.source) | ~> 3.61 |
+| <a name="provider_aws.target"></a> [aws.target](#provider\_aws.target) | ~> 3.61 |
 
 ### Modules
 
 | Name | Source | Version |
 |------|--------|---------|
-| <a name="module_cleanup_snapshots_lambda_monitoring"></a> [cleanup_snapshots_lambda_monitoring](#module_cleanup_snapshots_lambda_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
-| <a name="module_step_1_lambda_monitoring"></a> [step_1_lambda_monitoring](#module_step_1_lambda_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
-| <a name="module_step_2_lambda_monitoring"></a> [step_2_lambda_monitoring](#module_step_2_lambda_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
-| <a name="module_step_3_lambda_monitoring"></a> [step_3_lambda_monitoring](#module_step_3_lambda_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
-| <a name="module_step_4_lambda_monitoring"></a> [step_4_lambda_monitoring](#module_step_4_lambda_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
+| <a name="module_cleanup_snapshots_lambda_monitoring"></a> [cleanup\_snapshots\_lambda\_monitoring](#module\_cleanup\_snapshots\_lambda\_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
+| <a name="module_step_1_lambda_monitoring"></a> [step\_1\_lambda\_monitoring](#module\_step\_1\_lambda\_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
+| <a name="module_step_2_lambda_monitoring"></a> [step\_2\_lambda\_monitoring](#module\_step\_2\_lambda\_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
+| <a name="module_step_3_lambda_monitoring"></a> [step\_3\_lambda\_monitoring](#module\_step\_3\_lambda\_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
+| <a name="module_step_4_lambda_monitoring"></a> [step\_4\_lambda\_monitoring](#module\_step\_4\_lambda\_monitoring) | github.com/skyscrapers/terraform-cloudwatch//lambda_function | 2.0.1 |
 
 ### Resources
 
@@ -347,19 +347,20 @@ data "aws_iam_policy_document" "rds_replication_key" {
 
 | Name | Description | Type | Default | Required |
 |------|-------------|------|---------|:--------:|
-| <a name="input_name"></a> [name](#input_name) | Name of the setup | `string` | n/a | yes |
-| <a name="input_rds_instance_ids"></a> [rds_instance_ids](#input_rds_instance_ids) | List of IDs of the RDS instances to back up. If using Aurora, provide the cluster IDs instead | `list(string)` | n/a | yes |
-| <a name="input_target_account_kms_key_id"></a> [target_account_kms_key_id](#input_target_account_kms_key_id) | KMS key to use to encrypt replicated RDS snapshots in the target AWS account | `string` | n/a | yes |
-| <a name="input_is_aurora_cluster"></a> [is_aurora_cluster](#input_is_aurora_cluster) | Whether we're backing up Aurora clusters instead of RDS instances | `bool` | `false` | no |
-| <a name="input_retention_period"></a> [retention_period](#input_retention_period) | Snapshot retention period in days | `number` | `14` | no |
-| <a name="input_snapshot_schedule_expression"></a> [snapshot_schedule_expression](#input_snapshot_schedule_expression) | Snapshot frequency specified as a CloudWatch schedule expression. Can either be a `rate()` or `cron()` expression. Check the [AWS documentation](https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html#CronExpressions) on how to compose such expression. | `string` | `"cron(0 */6 * * ? *)"` | no |
+| <a name="input_name"></a> [name](#input\_name) | Name of the setup | `string` | n/a | yes |
+| <a name="input_rds_instance_ids"></a> [rds\_instance\_ids](#input\_rds\_instance\_ids) | List of IDs of the RDS instances to back up. If using Aurora, provide the cluster IDs instead | `list(string)` | n/a | yes |
+| <a name="input_target_account_kms_key_id"></a> [target\_account\_kms\_key\_id](#input\_target\_account\_kms\_key\_id) | KMS key to use to encrypt replicated RDS snapshots in the target AWS account | `string` | n/a | yes |
+| <a name="input_is_aurora_cluster"></a> [is\_aurora\_cluster](#input\_is\_aurora\_cluster) | Whether we're backing up Aurora clusters instead of RDS instances | `bool` | `false` | no |
+| <a name="input_lambda_monitoring_metric_period"></a> [lambda\_monitoring\_metric\_period](#input\_lambda\_monitoring\_metric\_period) | The metric period to use for the Lambdas CloudWatch alerts for monitoring. This should be equal or higher than the snapshoting period | `number` | `21600` | no |
+| <a name="input_retention_period"></a> [retention\_period](#input\_retention\_period) | Snapshot retention period in days | `number` | `14` | no |
+| <a name="input_snapshot_schedule_expression"></a> [snapshot\_schedule\_expression](#input\_snapshot\_schedule\_expression) | Snapshot frequency specified as a CloudWatch schedule expression. Can either be a `rate()` or `cron()` expression. Check the [AWS documentation](https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html#CronExpressions) on how to compose such expression. | `string` | `"cron(0 */6 * * ? *)"` | no |
 
 ### Outputs
 
 | Name | Description |
 |------|-------------|
-| <a name="output_source_region_sns_topic_arn"></a> [source_region_sns_topic_arn](#output_source_region_sns_topic_arn) | SNS topic ARN for the lambdas in the source region |
-| <a name="output_target_region_sns_topic_arn"></a> [target_region_sns_topic_arn](#output_target_region_sns_topic_arn) | SNS topic ARN for the lambdas in the target region |
+| <a name="output_source_region_sns_topic_arn"></a> [source\_region\_sns\_topic\_arn](#output\_source\_region\_sns\_topic\_arn) | SNS topic ARN for the lambdas in the source region |
+| <a name="output_target_region_sns_topic_arn"></a> [target\_region\_sns\_topic\_arn](#output\_target\_region\_sns\_topic\_arn) | SNS topic ARN for the lambdas in the target region |
 
 ## rds-proxy
 

diff --git a/snapshot-cross-account-replicator/lambda_source_account.tf b/snapshot-cross-account-replicator/lambda_source_account.tf
@@ -15,12 +15,6 @@ resource "aws_lambda_function" "step_1" {
   environment {
     variables = local.lambda_default_environment_variables
   }
-
-  lifecycle {
-    ignore_changes = [
-      filename
-    ]
-  }
 }
 
 resource "aws_cloudwatch_event_rule" "invoke_step_1_lambda" {
@@ -63,12 +57,6 @@ resource "aws_lambda_function" "step_2" {
       TYPE = "cross-region"
     })
   }
-
-  lifecycle {
-    ignore_changes = [
-      filename
-    ]
-  }
 }
 
 #### This EventBridge event rule filters RDS snapshot creation events
@@ -115,12 +103,6 @@ resource "aws_lambda_function" "step_3" {
       TYPE = "cross-account"
     })
   }
-
-  lifecycle {
-    ignore_changes = [
-      filename
-    ]
-  }
 }
 
 #### This EventBridge event rule either filters RDS snapshot copy events

diff --git a/snapshot-cross-account-replicator/lambda_target_account.tf b/snapshot-cross-account-replicator/lambda_target_account.tf
@@ -16,12 +16,6 @@ resource "aws_lambda_function" "step_4" {
   environment {
     variables = local.lambda_default_environment_variables
   }
-
-  lifecycle {
-    ignore_changes = [
-      filename
-    ]
-  }
 }
 
 ## This event will be triggered when the final snapshot has been copied to the target account
@@ -66,12 +60,6 @@ resource "aws_lambda_function" "cleanup_snapshots" {
   environment {
     variables = local.lambda_default_environment_variables
   }
-
-  lifecycle {
-    ignore_changes = [
-      filename
-    ]
-  }
 }
 
 resource "aws_cloudwatch_event_rule" "invoke_cleanup_snapshots_lambda" {

diff --git a/snapshot-cross-account-replicator/monitoring.tf b/snapshot-cross-account-replicator/monitoring.tf
@@ -89,7 +89,7 @@ module "step_1_lambda_monitoring" {
   lambda_function                            = aws_lambda_function.step_1.function_name
   sns_topic_arn                              = aws_sns_topic.source_region_topic.arn
   lambda_invocation_error_threshold          = 2
-  lambda_invocation_error_period             = 300 # 5 minutes
+  lambda_invocation_error_period             = var.lambda_monitoring_metric_period
   lambda_invocation_error_evaluation_periods = 1
 
   providers = {
@@ -102,7 +102,7 @@ module "step_2_lambda_monitoring" {
   lambda_function                            = aws_lambda_function.step_2.function_name
   sns_topic_arn                              = aws_sns_topic.source_region_topic.arn
   lambda_invocation_error_threshold          = 2
-  lambda_invocation_error_period             = 300 # 5 minutes
+  lambda_invocation_error_period             = var.lambda_monitoring_metric_period
   lambda_invocation_error_evaluation_periods = 1
 
   providers = {
@@ -115,7 +115,7 @@ module "step_3_lambda_monitoring" {
   lambda_function                            = aws_lambda_function.step_3.function_name
   sns_topic_arn                              = aws_sns_topic.target_region_topic.arn
   lambda_invocation_error_threshold          = 2
-  lambda_invocation_error_period             = 300 # 5 minutes
+  lambda_invocation_error_period             = var.lambda_monitoring_metric_period
   lambda_invocation_error_evaluation_periods = 1
 
   providers = {
@@ -128,7 +128,7 @@ module "step_4_lambda_monitoring" {
   lambda_function                            = aws_lambda_function.step_4.function_name
   sns_topic_arn                              = aws_sns_topic.target_region_topic.arn
   lambda_invocation_error_threshold          = 2
-  lambda_invocation_error_period             = 300 # 5 minutes
+  lambda_invocation_error_period             = var.lambda_monitoring_metric_period
   lambda_invocation_error_evaluation_periods = 1
 
   providers = {
@@ -141,7 +141,7 @@ module "cleanup_snapshots_lambda_monitoring" {
   lambda_function                            = aws_lambda_function.cleanup_snapshots.function_name
   sns_topic_arn                              = aws_sns_topic.target_region_topic.arn
   lambda_invocation_error_threshold          = 2
-  lambda_invocation_error_period             = 300 # 5 minutes
+  lambda_invocation_error_period             = var.lambda_monitoring_metric_period
   lambda_invocation_error_evaluation_periods = 1
 
   providers = {

diff --git a/snapshot-cross-account-replicator/variables.tf b/snapshot-cross-account-replicator/variables.tf
@@ -30,3 +30,9 @@ variable "target_account_kms_key_id" {
   description = "KMS key to use to encrypt replicated RDS snapshots in the target AWS account"
   type        = string
 }
+
+variable "lambda_monitoring_metric_period" {
+  description = "The metric period to use for the Lambdas CloudWatch alerts for monitoring. This should be equal or higher than the snapshoting period"
+  type        = number
+  default     = 21600 # 6 hours
+}