Resolved: terraform that creates single aurora cluster and schedules cluster to run during business hours

provider "aws" {
  region = local.region

}

locals {
  name   = "example-aurora"
  region = "us-east-1"
  tags   = {
    Owner       = "user"
    Environment = "dev"
  }
}

################################################################################
# Supporting Resources
################################################################################

resource "random_password" "master" {
  length = 10
}

module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "~> 3.0"

  name = "aurora_vpc"
  cidr = "10.99.0.0/18"

  enable_dns_support   = true
  enable_dns_hostnames = true

  azs              = ["${local.region}a", "${local.region}b", "${local.region}c"]
  public_subnets   = ["10.99.0.0/24", "10.99.1.0/24", "10.99.2.0/24"]
  private_subnets  = ["10.99.3.0/24", "10.99.4.0/24", "10.99.5.0/24"]
  database_subnets = ["10.99.7.0/24", "10.99.8.0/24", "10.99.9.0/24"]

  tags = local.tags
}

resource "aws_db_parameter_group" "muffy-pg" {
  family = "postgres13"
  name   = "peter-rds-param-group"
  parameter {
    apply_method = "immediate"
    name         = "autovacuum_naptime"
    value        = "30"
  }
  parameter {
    apply_method = "pending-reboot"
    name         = "autovacuum_max_workers"
    value        = "15"
  }
}

resource "aws_docdb_cluster_parameter_group" "muffy-cluster-pg" {
  name   = "peter-rds-param-group"
  family = "postgres13"
}

module "cluster" {
  source = "terraform-aws-modules/rds-aurora/aws"



  name           = "test-aurora-db-postgres96"
  engine         = "aurora-postgresql"
  engine_version = "13.7"
  instance_class = "db.t3.small"
  instances      = {
    one = {}
    two = {}
  }

  vpc_id  = module.vpc.vpc_id
  subnets = [module.vpc.database_subnets[0], module.vpc.database_subnets[1], module.vpc.database_subnets[2]]

  #  allowed_security_groups = ["sg-12345678"]
  allowed_cidr_blocks = ["10.99.0.0/18"]

  storage_encrypted   = true
  apply_immediately   = true
  monitoring_interval = 10


  db_parameter_group_name         = aws_db_parameter_group.muffy-pg.name
  db_cluster_parameter_group_name = aws_docdb_cluster_parameter_group.muffy-cluster-pg.name

  enabled_cloudwatch_logs_exports = ["postgresql"]

  tags = {
    Environment = "dev"
    Terraform   = "true"
  }
}

variable "environment" {
  default = "dev"
}

module "rds_schedule" {
  depends_on = [module.cluster]
  source     = "github.com/barryw/terraform-aws-rds-scheduler"
  # version = "~> 2.0.0"

  /* Don't stop RDS in production! */
  skip_execution = var.environment == "prod"
  identifier     = "peter-scheduler"

  /* Start the RDS cluster at 6:50am EDT Monday - Friday */
  up_schedule   = "cron(50 10 ? * MON-FRI *)"
  /* Stop the RDS cluster at 9pm EDT every night */
  down_schedule = "cron(0 1 * * ? *)"

  rds_identifier = module.cluster.identifier
  is_cluster     = true
}