public subnets

이전 시간에 디폴트 VPC를 생성했다.
cidr 범위는 10.1.0.0/16이었다.

VPC의 IP역시 subnet(public, private)으로 나눠서 사용한다.

Public subnet

로드밸런서와 bastion 서버를 위해 퍼블릭 서브넷이 필요하다.

• main.tf

(윗 부분 코드 생략)

data "aws_region" "current" {}

main.tf에는 위의 코드 한 줄만 새롭게 추가된다.

• network.tf

resource "aws_vpc" "main" {
  cidr_block           = "10.1.0.0/16"
  enable_dns_support   = true
  enable_dns_hostnames = true

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-vpc")
  )
}

resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-main")
  )
}


#####################################################
# Public Subnets - Inbound/Outbound Internet Access #
#####################################################
resource "aws_subnet" "public_a" {
  cidr_block              = "10.1.1.0/24"
  map_public_ip_on_launch = true
  vpc_id                  = aws_vpc.main.id
  availability_zone       = "${data.aws_region.current.name}a"

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-a")
  )
}

resource "aws_route_table" "public_a" {
  vpc_id = aws_vpc.main.id

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-a")
  )
}

resource "aws_route_table_association" "pulic_a" {
  subnet_id      = aws_subnet.public_a.id
  route_table_id = aws_route_table.public_a.id
}

resource "aws_route" "public_internet_access_a" {
  route_table_id         = aws_route_table.public_a.id
  destination_cidr_block = "0.0.0.0/0"
  gateway_id             = aws_internet_gateway.main.id
}

resource "aws_eip" "public_a" {
  vpc = true
  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-a")
  )
}

resource "aws_nat_gateway" "public_a" {
  allocation_id = aws_eip.public_a.id
  subnet_id     = aws_subnet.public_a.id

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-a")
  )
}

resource "aws_subnet" "public_b" {
  cidr_block              = "10.1.2.0/24"
  map_public_ip_on_launch = true
  vpc_id                  = aws_vpc.main.id
  availability_zone       = "${data.aws_region.current.name}b"

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-b")
  )
}

resource "aws_route_table" "public_b" {
  vpc_id = aws_vpc.main.id

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-b")
  )
}

resource "aws_route_table_association" "public_b" {
  subnet_id      = aws_subnet.public_b.id
  route_table_id = aws_route_table.public_b.id
}

resource "aws_route" "public_internet_access_b" {
  route_table_id         = aws_route_table.public_b.id
  destination_cidr_block = "0.0.0.0/0"
  gateway_id             = aws_internet_gateway.main.id
}

resource "aws_eip" "public_b" {
  vpc = true

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-b")
  )
}

resource "aws_nat_gateway" "public_b" {
  allocation_id = aws_eip.public_b.id
  subnet_id     = aws_subnet.public_b.id

  tags = merge(
    local.common_tags,
    map("Name", "${local.prefix}-public-b")
  )
}