# Title: site/nat_gateway.tf
# Description: Create a NAT gateway for private subnets

# Note: For true high availabity, you will want:
#       -An EIP and NAT GW per public subnet
#       -Route table per private subnet to route to NAT GW in same AZ

# Create the required Elastic IPs to be assigned to the NAT Gateways
resource "aws_eip" "eip_nat01" {
  vpc = true
}

resource "aws_eip" "eip_nat02" {
  vpc = true
}

resource "aws_eip" "eip_nat03" {
  vpc = true
}

# Create the NAT Gateways
resource "aws_nat_gateway" "nat_gw01" {
  subnet_id = "${aws_subnet.subnet01-public.id}"
  allocation_id = "${aws_eip.eip_nat01.id}"
  tags { Name = "nat_gw01" }

  # Dependencies: Internet Gateway and EIP
  depends_on = ["aws_internet_gateway.myigw", "aws_eip.eip_nat01"]
}

resource "aws_nat_gateway" "nat_gw02" {
  subnet_id = "${aws_subnet.subnet02-public.id}"
  allocation_id = "${aws_eip.eip_nat02.id}"
  tags { Name = "nat_gw02" }

  # Dependencies: Internet Gateway and EIP
  depends_on = ["aws_internet_gateway.myigw", "aws_eip.eip_nat02"]
}

resource "aws_nat_gateway" "nat_gw03" {
  subnet_id = "${aws_subnet.subnet03-public.id}"
  allocation_id = "${aws_eip.eip_nat03.id}"
  tags { Name = "nat_gw03" }

  # Dependencies: Internet Gateway and EIP
  depends_on = ["aws_internet_gateway.myigw", "aws_eip.eip_nat03"]
}

# Route to the NAT Gateway provided elsewhere (in private route table)