CloudFormation ALB + AutoScaling 3Tier

실습 목표

CloudFormation을 이용하여 웹 서비스용 3-Tier Architecture를 자동으로 생성한다.

다음 리소스를 자동으로 생성한다.

VPC
Public Subnet (2)
Private Subnet (2)
Internet Gateway
Route Table
Application Load Balancer
Target Group
Auto Scaling Group
EC2 Instance

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1 CloudFormation Template 생성

파일 생성

three-tier-autoscaling.yaml

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2 CloudFormation Template 작성

AWSTemplateFormatVersion: '2010-09-09'
Description: ALB + AutoScaling 3 Tier Architecture
 
Parameters:
 
  InstanceType:
    Type: String
    Default: t3.micro
 
  KeyName:
    Type: AWS::EC2::KeyPair::KeyName
 
  VpcCIDR:
    Type: String
    Default: 10.0.0.0/16
 
Resources:
 
# VPC
 
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: !Ref VpcCIDR
      Tags:
        - Key: Name
          Value: 이니셜-vpc-cf
 
# Internet Gateway
 
  InternetGateway:
    Type: AWS::EC2::InternetGateway
 
  AttachGateway:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway
 
# Public Subnet
 
  PublicSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.1.0/24
      AvailabilityZone: ap-northeast-2a
 
  PublicSubnet2:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.2.0/24
      AvailabilityZone: ap-northeast-2c
 
# Security Group
 
  WebSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: web sg
      VpcId: !Ref VPC
 
      SecurityGroupIngress:
 
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
 
# Application Load Balancer
 
  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: 이니셜-alb-cf
      Subnets:
        - !Ref PublicSubnet1
        - !Ref PublicSubnet2
      SecurityGroups:
        - !Ref WebSecurityGroup
 
# Target Group
 
  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      Port: 80
      Protocol: HTTP
      VpcId: !Ref VPC
 
# Listener
 
  Listener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      LoadBalancerArn: !Ref LoadBalancer
      Port: 80
      Protocol: HTTP
 
      DefaultActions:
        - Type: forward
          TargetGroupArn: !Ref TargetGroup
 
# Launch Template
 
  LaunchTemplate:
 
    Type: AWS::EC2::LaunchTemplate
 
    Properties:
 
      LaunchTemplateData:
 
        ImageId: ami-0bb8c0d387143b435
 
        InstanceType: !Ref InstanceType
 
        KeyName: !Ref KeyName
 
        SecurityGroupIds:
          - !Ref WebSecurityGroup
 
        UserData:
 
          Fn::Base64: |
 
            #!/bin/bash
            yum update -y
            yum install httpd -y
            systemctl start httpd
            systemctl enable httpd
            echo "CloudFormation Web Server" > /var/www/html/index.html
 
# Auto Scaling Group
 
  AutoScalingGroup:
 
    Type: AWS::AutoScaling::AutoScalingGroup
 
    Properties:
 
      VPCZoneIdentifier:
 
        - !Ref PublicSubnet1
        - !Ref PublicSubnet2
 
      LaunchTemplate:
 
        LaunchTemplateId: !Ref LaunchTemplate
        Version: !GetAtt LaunchTemplate.LatestVersionNumber
 
      MinSize: 1
      MaxSize: 4
      DesiredCapacity: 2
 
      TargetGroupARNs:
        - !Ref TargetGroup
 
Outputs:
 
  LoadBalancerDNS:
 
    Description: ALB DNS
 
    Value: !GetAtt LoadBalancer.DNSName

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3 Stack 생성

콘솔 이동

CloudFormation
→ Stack 생성

Template 업로드

three-tier-autoscaling.yaml

Stack 이름

이니셜-stack-3tier

Parameter 입력

InstanceType : t3.micro
KeyName : 이니셜-key-ec2

Stack 생성

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4 Stack 생성 확인

상태 확인

CREATE_COMPLETE

생성된 리소스

VPC
ALB
Auto Scaling
EC2

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5 Web 서비스 접속

CloudFormation Output 확인

LoadBalancerDNS

브라우저 접속

<http://ALB-DNS>

웹 페이지 확인

CloudFormation Web Server

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6 Auto Scaling 확인

EC2 콘솔 이동

Auto Scaling Group

확인 항목

Desired Capacity
Instances수업에서 설명하면 좋은 포인트

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CloudFormation 장점

Infrastructure as Code
환경 재현 가능
자동 배포
대규모 인프라 관리

CloudFormation 흐름

Template 작성
        ↓
Stack 생성
        ↓
AWS 리소스 자동 생성
        ↓
Stack 삭제
        ↓
모든 리소스 자동 삭제

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