Invoke Lambda with Cloudwatch Event Rule | Terraform

I needed to invoke lambda from an Cloudwatch Event rule. With the following code, I created a lambda function.
Note: data.archive_file.awesome-lambda and aws_iam_role.awesome-lambda is not covered here.

resource "aws_lambda_function" "awesome-lambda" {
  function_name    = "awesome-lambda"
  filename          = data.archive_file.awesome-lambda.output_path
  runtime          = "python3.8"
  handler          = "awesome-lambda.lambda_handler
  role             = aws_iam_role.awesome-lambda.arn
  source_code_hash = data.archive_file.awesome-lambda.output_base64sha256
  timeout          = 30
  memory_size      = 128
}

I have created an Cloudwatch Event Rule with following code

resource "aws_cloudwatch_event_rule" "cloudwatch-rule" {
  name        = "cloudwatch-rule"
  description = "Alarms based on Autoscaling events"
  event_pattern = jsonencode({
    "detail-type": ["EC2 Instance Launch Successful", "EC2 Instance Terminate Successful"],
    "source": ["aws.autoscaling"],
    "detail": {
      "AutoScalingGroupName": [
        "my-dumb-autoscale-gro"]
    }
  })
}

It should work right ? Unfortunately it is missing permission. To fix permission issue, I wrote following code and it starts working, cheers.

resource "aws_lambda_permission" "awesome-lambda-perm" {
  action        = "lambda:InvokeFunction"
  function_name = aws_lambda_function.awesome-lambda.function_name
  principal     = "events.amazonaws.com"
  source_arn    = aws_cloudwatch_event_rule.cloudwatch-rule.arn
}