AWS 3 Tier architecture / terraform 정리 (미완)

link: https://github.com/rookieboba/Terraform-3tier-architecture-AWS

 

AWS 아키텍처 다이어그램

• 3 tier architecture (draw.io 이용)

---

AWS CLI로 AWS 아키텍처 terraform 띄우기

1️⃣ CloudFormation Stack에서 생성된 리소스 목록 가져오기

aws cloudformation describe-stack-resources --stack-name cf.stack

예시 결과

{
    "StackResources": [
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "WebServer",
            "PhysicalResourceId": "i-0ab12345cde678fgh",
            "ResourceType": "AWS::EC2::Instance",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "AppServer",
            "PhysicalResourceId": "i-0fgh67890ijk123abc",
            "ResourceType": "AWS::EC2::Instance",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "Database",
            "PhysicalResourceId": "db-xyz987654321",
            "ResourceType": "AWS::RDS::DBInstance",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "VPC",
            "PhysicalResourceId": "vpc-abc12def34gh56ij7",
            "ResourceType": "AWS::EC2::VPC",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "PublicSubnet",
            "PhysicalResourceId": "subnet-9876ab12cde34fgh5",
            "ResourceType": "AWS::EC2::Subnet",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "PrivateSubnet",
            "PhysicalResourceId": "subnet-12345def67ab89ghi",
            "ResourceType": "AWS::EC2::Subnet",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        },
        {
            "StackName": "cf.stack",
            "StackId": "arn:aws:cloudformation:us-east-1:123456789012:stack/cf.stack/a1b2c3d4-e5f6-7890-abcd-ef1234567890",
            "LogicalResourceId": "ALB",
            "PhysicalResourceId": "alb-0xy123z456ab78def",
            "ResourceType": "AWS::ElasticLoadBalancingV2::LoadBalancer",
            "Timestamp": "2025-02-10T10:00:00.000Z",
            "ResourceStatus": "CREATE_COMPLETE"
        }
    ]
}

---

2️⃣ Terraform Import 실행

• CloudFormation이 생성한 모든 리소스를 Terraform 코드로 가져오기

# Terraformer로 AWS 리소스 Import

git clone https://github.com/GoogleCloudPlatform/terraformer
cd terraformer
go build -o terraformer .
sudo mv terraformer /usr/local/bin/

# 설치 확인
terraformer --version

mkdir ~/terraform-3tier-architecture
cd ~/terraform-3tier-architecture

# AWS 프로필 설정 (필요 시):
export AWS_PROFILE=<profile-name>
export AWS_REGION=<region>

# terraformer 실행
terraformer import aws \
  --resources=all \
  --regions=<region> \
  --filter=Name=stack-name;Value=<stack-name>

# 파일 정리
mv generated/aws/provider.tf provider.tf
mv generated/aws/terraform.tfstate terraform.tfstate
mv generated/aws/*.tf .

# 네트워크 관련 파일 이동
mkdir vpc networking compute database
mv aws_vpc*.tf aws_subnet*.tf vpc/
mv aws_route_table*.tf aws_nat_gateway*.tf networking/

# 컴퓨팅 및 데이터베이스 관련 파일 이동
mv aws_instance*.tf aws_elb*.tf compute/
mv aws_db_instance*.tf aws_db_subnet_group*.tf database/

---

3️⃣ Terraform 코드 정리

• 간결하게 정리하는 게 더 좋다. variables.tf 추가

📁 terraform-3tier-architecture/
│── 📄 provider.tf            # AWS 프로바이더 설정
│── 📄 variables.tf           # 변수 정의
│── 📄 terraform.tfvars       # 변수 값 설정
│── 📄 main.tf                # 모든 모듈을 연결하는 메인 파일
│── 📄 outputs.tf             # 주요 리소스 출력
├── 📁 vpc/                   # VPC 및 Subnet
│    ├── 📄 aws_vpc.tf
│    ├── 📄 aws_subnet.tf
│    ├── 📄 aws_internet_gateway.tf
│    ├── 📄 aws_nat_gateway.tf
│    ├── 📄 aws_security_group.tf
├── 📁 networking/            # Routing Table 설정
│    ├── 📄 aws_route_table.tf
├── 📁 compute/               # EC2 인스턴스 및 로드밸런서
│    ├── 📄 aws_instance.tf
│    ├── 📄 aws_alb.tf
│    ├── 📄 aws_nlb.tf

• 최종 결과

(1) provider.tf - AWS 프로바이더 설정

provider "aws" {
  region = var.aws_region
}

---

(2) variables.tf - 변수 정의

# 변수 정의
variable "aws_region" {
  description = "AWS Region"
  type        = string
  default     = "ap-northeast-2" # 서울 리전
}

variable "vpc_cidr" {
  description = "VPC CIDR Block"
  type        = string
  default     = "10.0.0.0/16"
}

variable "public_subnet_cidrs" {
  description = "Public Subnet CIDR Blocks"
  type        = list(string)
  default     = ["10.0.1.0/24", "10.0.2.0/24"]
}

variable "private_subnet_cidrs" {
  description = "Private Subnet CIDR Blocks"
  type        = list(string)
  default     = ["10.0.3.0/24", "10.0.4.0/24", "10.0.5.0/24", "10.0.6.0/24"]
}

variable "instance_type" {
  description = "EC2 Instance Type"
  type        = string
  default     = "t3.micro"
}

variable "alb_name" {
  description = "Application Load Balancer Name"
  type        = string
  default     = "app-alb"
}

variable "nlb_name" {
  description = "Network Load Balancer Name"
  type        = string
  default     = "app-nlb"
}

variable "key_name" {
  description = "Name of the AWS Key Pair"
  type        = string
  default     = "my-key-pair"
}

---

(3) terraform.tfvars (변수 값 설정 파일)

# 변수 값 설정
aws_region          = "ap-northeast-2"
vpc_cidr           = "10.0.0.0/16"
public_subnet_cidrs = ["10.0.1.0/24", "10.0.2.0/24"]
private_subnet_cidrs = ["10.0.3.0/24", "10.0.4.0/24", "10.0.5.0/24", "10.0.6.0/24"]
instance_type       = "t3.micro"
alb_name           = "web-alb"
nlb_name           = "app-nlb"
key_name          = "your-key-pair-name"

 

(4) main.tf (모든 리소스 연결 메인 파일)

# 메인 파일: 모든 모듈 연결
module "vpc" {
  source = "./vpc"
}

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

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

(5) outputs.tf (주요 리소스 정보 출력)

# 주요 리소스 출력
output "vpc_id" {
  value = module.vpc.vpc_id
}

output "public_subnet_ids" {
  value = module.vpc.public_subnet_ids
}

output "private_subnet_ids" {
  value = module.vpc.private_subnet_ids
}

output "web_server_ips" {
  value = module.compute.web_server_ips
}

output "alb_dns_name" {
  value = module.compute.alb_dns_name
}

output "nlb_dns_name" {
  value = module.compute.nlb_dns_name
}

 

 

(6) vpc/aws_vpc.tf - VPC 및 서브넷

# VPC 설정
resource "aws_vpc" "main" {
  cidr_block = var.vpc_cidr
  enable_dns_support   = true
  enable_dns_hostnames = true

  tags = {
    Name = "MainVPC"
  }
}

---

(7) vpc/aws_subnet.tf - 라우팅 설정

# 서브넷 설정
resource "aws_subnet" "public" {
  count                   = length(var.public_subnet_cidrs)
  vpc_id                  = aws_vpc.main.id
  cidr_block              = var.public_subnet_cidrs[count.index]
  map_public_ip_on_launch = true

  tags = {
    Name = "PublicSubnet-${count.index + 1}"
  }
}

resource "aws_subnet" "private" {
  count      = length(var.private_subnet_cidrs)
  vpc_id     = aws_vpc.main.id
  cidr_block = var.private_subnet_cidrs[count.index]

  tags = {
    Name = "PrivateSubnet-${count.index + 1}"
  }
}

 

---

(8) vpc/aws_internet_gateway.tf - EInstance

# 인터넷 게이트웨이 설정
resource "aws_internet_gateway" "igw" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "InternetGateway"
  }
}

---

(9) vpc/aws_nat_gateway.tf

# NAT Gateway 설정
resource "aws_nat_gateway" "nat" {
  allocation_id = aws_eip.nat.id
  subnet_id     = aws_subnet.public[0].id

  tags = {
    Name = "NATGateway"
  }
}

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

---

(10) networking/aws_route_table.tf

# 라우팅 테이블 설정
resource "aws_route_table" "public" {
  vpc_id = aws_vpc.main.id

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

  tags = {
    Name = "PublicRouteTable"
  }
}

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

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

  tags = {
    Name = "PrivateRouteTable"
  }
}

resource "aws_route_table_association" "public" {
  count          = length(aws_subnet.public)
  subnet_id      = aws_subnet.public[count.index].id
  route_table_id = aws_route_table.public.id
}

resource "aws_route_table_association" "private" {
  count          = length(aws_subnet.private)
  subnet_id      = aws_subnet.private[count.index].id
  route_table_id = aws_route_table.private.id
}

(11) compute/aws_instance.tf

# EC2 인스턴스 설정 (총 6대)
resource "aws_instance" "web_server_1" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.public[0].id
  key_name      = var.key_name

  tags = {
    Name = "WebServer-1"
  }
}

resource "aws_instance" "web_server_2" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.public[1].id
  key_name      = var.key_name

  tags = {
    Name = "WebServer-2"
  }
}

resource "aws_instance" "was_server_1" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.private[0].id
  key_name      = var.key_name

  tags = {
    Name = "WASServer-1"
  }
}

resource "aws_instance" "was_server_2" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.private[1].id
  key_name      = var.key_name

  tags = {
    Name = "WASServer-2"
  }
}

resource "aws_instance" "db_server_1" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.private[2].id
  key_name      = var.key_name

  tags = {
    Name = "DBServer-1"
  }
}

resource "aws_instance" "db_server_2" {
  ami           = "ami-0abcdef1234567890"
  instance_type = var.instance_type
  subnet_id     = aws_subnet.private[3].id
  key_name      = var.key_name

  tags = {
    Name = "DBServer-2"
  }
}

(12) compute/aws_alb.tf

# Application Load Balancer 설정
resource "aws_lb" "alb" {
  name               = var.alb_name
  internal           = false
  load_balancer_type = "application"
  security_groups    = [aws_security_group.default.id]
  subnets            = aws_subnet.public[*].id

  tags = {
    Name = "AppALB"
  }
}

 

(13) compute/aws_nlb.tf

# Network Load Balancer 설정
resource "aws_lb" "nlb" {
  name               = var.nlb_name
  internal           = true
  load_balancer_type = "network"
  subnets            = aws_subnet.private[*].id

  tags = {
    Name = "AppNLB"
  }
}

• terraform plan 확인 필수

terraform init
terraform plan
terraform apply -auto-approve