code-dumps/terraform/aws-vpc/vpc-subnets.tf

variable "globalTags" {
  type = "map"
  default {}
}

variable "resource_prefix" {}

terraform {
  required_version = ">= 0.9.9"
}

# VPC
resource "aws_vpc" "tf-vpc1" {
  cidr_block = "10.10.0.0/16"

  tags = "${merge(var.globalTags, map("Name","KFLAB"))}"
}

# Get all AZs
data "aws_availability_zones" "available" {
  state = "available"
}

# 2 az, 1 public subnet in each
resource "aws_subnet" "PublicSubnet" {
  vpc_id            = "${aws_vpc.tf-vpc1.id}"
  cidr_block        = "10.10.${count.index + 1}.0/24"
  availability_zone = "${data.aws_availability_zones.available.names[count.index]}"

  tags = "${merge(var.globalTags, map("Name","PublicSubnet-${count.index + 1}"))}"

  count = "${length(data.aws_availability_zones.available.names)}"
}


# 2 az, 1 private subnet in each
resource "aws_subnet" "PrivateSubnet" {
  vpc_id            = "${aws_vpc.tf-vpc1.id}"
  cidr_block        = "10.10.${count.index + 21}.0/24"
  availability_zone = "${data.aws_availability_zones.available.names[count.index]}"

  tags = "${merge(var.globalTags, map("Name","PrivateSubnet-${count.index + 1}"))}"

  count = "${length(data.aws_availability_zones.available.names)}"
}

# IGW
resource "aws_internet_gateway" "igw1" {
  vpc_id = "${aws_vpc.tf-vpc1.id}"

  tags = "${merge(var.globalTags, map("Name","IGW1"))}"
}

# Public RT
resource "aws_route_table" "PublicRouteTable" {
  vpc_id = "${aws_vpc.tf-vpc1.id}"

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = "${aws_internet_gateway.igw1.id}"
  }

  tags = "${merge(var.globalTags, map("Name","PublicRouteTable"))}"
}

# Associate Public RT
resource "aws_route_table_association" "PublicRTAsso" {
  subnet_id      = "${element(aws_subnet.PublicSubnet.*.id, count.index)}"
  route_table_id = "${aws_route_table.PublicRouteTable.id}"
  count = "${length(data.aws_availability_zones.available.names)}"
}

# NAT Gateway
resource "aws_eip" "ngw1-eip" {
	vpc = true
	tags = "${var.globalTags}"
}

resource "aws_nat_gateway" "ngw1" {
  allocation_id = "${aws_eip.ngw1-eip.id}"
  subnet_id     = "${aws_subnet.PublicSubnet.0.id}"
  tags = "${merge(var.globalTags, map("Name","NGW1"))}"
}

# Private RT
resource "aws_route_table" "PrivateRouteTable" {
  vpc_id = "${aws_vpc.tf-vpc1.id}"

  route {
    cidr_block     = "0.0.0.0/0"
    nat_gateway_id = "${aws_nat_gateway.ngw1.id}"
  }

  tags = "${merge(var.globalTags, map("Name","PrivateRouteTable"))}"
}

# Associate Private RT
resource "aws_route_table_association" "PrivateRTAsso" {
  subnet_id      = "${element(aws_subnet.PrivateSubnet.*.id, count.index)}"
  route_table_id = "${aws_route_table.PrivateRouteTable.id}"
  count = "${length(data.aws_availability_zones.available.names)}"
}

output "NGW IP" {
  value = "${aws_nat_gateway.ngw1.public_ip}"
}