updated readme and variable for slack

examples/complete-psql-replica/main.tf

@@ -107,6 +107,7 @@ module "rds-pg" {
   cloudwatch_metric_alarms_enabled = true
   alarm_cpu_threshold_percent      = 70
   disk_free_storage_space          = "10000000" # in bytes
+  slack_notification_enabled       = false
   slack_username                   = "Admin"
   slack_channel                    = "postgresql-notification"
   slack_webhook_url                = "https://hooks/xxxxxxxx"

examples/complete/main.tf

@@ -121,6 +121,7 @@ module "rds-pg" {
   cloudwatch_metric_alarms_enabled = true
   alarm_cpu_threshold_percent      = 70
   disk_free_storage_space          = "10000000" # in bytes
+  slack_notification_enabled       = false
   slack_username                   = "Admin"
   slack_channel                    = "postgresql-notification"
   slack_webhook_url                = "https://hooks/xxxxxxxx"

main.tf

@@ -244,6 +244,7 @@ EOF
 }
 
 data "archive_file" "lambdazip" {
+  count             = var.slack_notification_enabled ? 1 : 0
   type        = "zip"
   output_path = "${path.module}/lambda/sns_slack.zip"
 
@@ -252,6 +253,7 @@ data "archive_file" "lambdazip" {
 
 
 module "cw_sns_slack" {
+  count             = var.slack_notification_enabled ? 1 : 0
   source = "./lambda"
 
   name          = format("%s-%s-%s", var.environment, var.name, "sns-slack")
@@ -273,16 +275,18 @@ module "cw_sns_slack" {
 }
 
 resource "aws_sns_topic_subscription" "slack-endpoint" {
-  endpoint               = module.cw_sns_slack.arn
+  count             = var.slack_notification_enabled ? 1 : 0
+  endpoint               = module.cw_sns_slack[0].arn
   protocol               = "lambda"
   endpoint_auto_confirms = true
   topic_arn              = aws_sns_topic.slack_topic[0].arn
 }
 
 resource "aws_lambda_permission" "sns_lambda_slack_invoke" {
+  count             = var.slack_notification_enabled ? 1 : 0
   statement_id  = "sns_slackAllowExecutionFromSNS"
   action        = "lambda:InvokeFunction"
-  function_name = module.cw_sns_slack.arn
+  function_name = module.cw_sns_slack[0].arn
   principal     = "sns.amazonaws.com"
   source_arn    = aws_sns_topic.slack_topic[0].arn
 }

variables.tf

@@ -234,6 +234,12 @@ variable "ok_actions" {
   default     = []
 }
 
+variable "slack_notification_enabled" {
+  type        = bool
+  description = "Whether to enable/disable slack notification."
+  default     = false
+}
+
 variable "slack_webhook_url" {
   description = "The Slack Webhook URL where notifications will be sent."
   default     = ""