2 identical VPC's with same CIDR blocks being created

Terraform
1

Hi everyone

I am creating a simple VPC and PostgreSQL DB in RDS with terraform scripts, but it keeps creating 2 x VPC’s with the same CIDR block.

main.tf:

provider "aws" {

    region = var.region

    shared_credentials_file = var.creds

  }

module "vpc" {

  source = "./vpc"

}

module "dbserver" {

  source = "./db"

}

vpc.tf:

module "settings" {
  source = "./../settings"
}

### VPC RESOURCE ###
resource "aws_vpc" "xxxVpcDev" {
    cidr_block = "10.0.0.0/16"
    tags = {
    Name = "xxx Dev VPC"
    }
}

### SUBNET RESOURCES ###
resource "aws_subnet" "Public_subnet" {
  vpc_id            = aws_vpc.xxxVpcDev.id
  cidr_block        = "10.0.1.0/24"
  availability_zone = "af-south-1a"
  map_public_ip_on_launch = true

  tags = {
    Name = "Public Subnet"
  }

  depends_on = [aws_vpc.xxxVpcDev]
}

resource "aws_subnet" "Private_subnet1" {
  vpc_id            = aws_vpc.xxxVpcDev.id
  cidr_block        = "10.0.2.0/24"
  availability_zone = "af-south-1b"

  tags = {
    Name = "Private Subnet1"
  }

  depends_on = [aws_vpc.xxxVpcDev]
}

resource "aws_subnet" "Private_subnet2" {
  vpc_id            = aws_vpc.xxxVpcDev.id
  cidr_block        = "10.0.3.0/24"
  availability_zone = "af-south-1c"

  tags = {
    Name = "Private Subnet2"
  }

  depends_on = [aws_vpc.xxxVpcDev]
}

### Create DB Subnet Group in VPC ###
resource "aws_db_subnet_group" "default" {
  #name       = "fh-sn-grp"
  name       = module.settings.sn_grp_name
  subnet_ids = [aws_subnet.Private_subnet1.id, aws_subnet.Private_subnet2.id]
  tags = {
    Name = "My DB subnet group"
  }

  #depends_on = [aws_vpc.xxxVpcDev]
}


### IGW RESOURCE ###
resource "aws_internet_gateway" "fh-gw" {
  vpc_id = aws_vpc.xxxVpcDev.id

  tags = {
    Name = "FHIGW"
  }

  depends_on = [aws_vpc.xxxVpcDev]
}

db. tf:

module "vpc" {
  source = "./../vpc"
}

module "settings" {
  source = "./../settings"
}

resource "aws_db_instance" "fhpgb1" {
  allocated_storage        = 20 # gigabytes (min 20)
  #backup_retention_period  = 7   # in days
  #db_subnet_group_name     = "fh-sn-grp"
  db_subnet_group_name     = module.settings.sn_grp_name
  #db_subnet_group_name     = "${var.rds_private_subnet_group}"
  engine                   = "postgres"
  engine_version           = "13.3"
  identifier               = "fhpgdb1"
  instance_class           = "db.t3.micro"
  multi_az                 = false
  name                     = "mydb1"
  #parameter_group_name     = "mydbparamgroup1" # if you have tuned it
  password                 = "null"  
  #password                 = "${trimspace(file("${path.module}/secrets/mydb1-password.txt"))}"
  port                     = 5432
  publicly_accessible      = false
  storage_encrypted        = true # you should always do this
  storage_type             = "gp2"
  username                 = "mydb1"
  #vpc_security_group_ids   = ["${aws_security_group.mydb1.id}"]
  skip_final_snapshot      = true

  #depends_on = [module.vpc.fhvpc]
  depends_on = [module.settings.sn_grp_name]

}

settings.tf:

output sn_grp_name {

  value = "fh-sn-grp"

}

I cannot for the life of me figure out why it is doing this - any help will be appreciated!

2

It is difficult to see as it currently stands. Would you be able to reformat the code and show the directory structure?

3

It’s pretty straightforward:

main.tf is in root
vpc.tf is in a directory under root called \vpc
db.tf is in a directory under root called \db

4

I’d also appreciate proper code formatting :slight_smile:

As per my understanding the VPC module is called twice, so it is created twice.