Terraform module to create AWS SNS Topic Subscription

Question

I am not able to find terraform module to create AWS SNS Topic subscription. eg: I used "terraform-aws-modules/sns/aws" to create SNS topic. Can someone point me to source module for subscription?

Answer 1

You should prefer resources to modules unless you have a complex use case involving many interacting resources in a common pattern.

Modules are best suited to standardizing common patterns. A module can be made for a single resource, but it's rarely worth the overhead.

Here is a worked example based on a real system. This creates an SNS topic and subscribes a Lambda function to it:

resource "aws_sns_topic" "kpis" {
  name = var.sns_topic_name
}

resource "aws_sns_topic_subscription" "invoke_with_sns" {
  topic_arn = aws_sns_topic.kpis.arn
  protocol  = "lambda"
  endpoint  = module.kpis.function_arn
}

resource "aws_lambda_permission" "allow_sns_invoke" {
  statement_id  = "AllowExecutionFromSNS"
  action        = "lambda:InvokeFunction"
  function_name = module.lambda.function_name
  principal     = "sns.amazonaws.com"
  source_arn    = aws_sns_topic.kpis.arn
}

You can read more about aws_sns_topic_subscription here: https://www.terraform.io/docs/providers/aws/r/sns_topic_subscription.html