Transit Gateway と Network Firewall によるマルチVPC構成

AWSTemplateFormatVersion: '2010-09-09'
Description: 'Multi-VPC Hub and Spoke Architecture using AWS Transit Gateway and AWS Network Firewall.'

Parameters:
  Environment:
    Type: String
    Default: dev
    AllowedValues:
      - dev
      - prod
    Description: Environment name

Resources:
  # 1. AWS Transit Gateway
  TransitGateway:
    Type: AWS::EC2::TransitGateway
    Properties:
      Description: 'Transit Gateway for Hub and Spoke routing control'
      AutoAcceptSharedAttachments: enable
      DefaultRouteTableAssociation: disable
      DefaultRouteTablePropagation: disable
      Tags:
        - Key: Name
          Value: !Sub 'hub-spoke-tgw-${Environment}'

  # TGW Route Tables
  SpokeRouteTable:
    Type: AWS::EC2::TransitGatewayRouteTable
    Properties:
      TransitGatewayId: !Ref TransitGateway
      Tags:
        - Key: Name
          Value: !Sub 'spoke-tgw-rt-${Environment}'

  HubRouteTable:
    Type: AWS::EC2::TransitGatewayRouteTable
    Properties:
      TransitGatewayId: !Ref TransitGateway
      Tags:
        - Key: Name
          Value: !Sub 'hub-tgw-rt-${Environment}'

  # 2. Hub VPC (Inspection & Egress VPC)
  HubVPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsHostnames: true
      EnableDnsSupport: true
      Tags:
        - Key: Name
          Value: !Sub 'hub-vpc-${Environment}'

  InternetGateway:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
        - Key: Name
          Value: !Sub 'hub-igw-${Environment}'

  VPCGatewayAttachment:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref HubVPC
      InternetGatewayId: !Ref InternetGateway

  # Hub VPC Subnets
  PublicSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref HubVPC
      CidrBlock: 10.0.1.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      MapPublicIpOnLaunch: true
      Tags:
        - Key: Name
          Value: !Sub 'hub-public-subnet-${Environment}'

  InspectionSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref HubVPC
      CidrBlock: 10.0.2.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'hub-inspection-subnet-${Environment}'

  TgwSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref HubVPC
      CidrBlock: 10.0.3.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'hub-tgw-subnet-${Environment}'

  # 3. AWS Network Firewall in Hub VPC
  FirewallRuleGroup:
    Type: AWS::NetworkFirewall::RuleGroup
    Properties:
      RuleGroupName: !Sub 'egress-rules-${Environment}'
      Type: STATEFUL
      Capacity: 100
      RuleGroup:
        RulesSource:
          StatefulRules:
            - Action: DROP
              Header:
                Destination: any
                DestinationPort: any
                Direction: ANY
                Protocol: HTTP
                Source: any
                SourcePort: any
              RuleOptions:
                - Name: sid
                  Value: '1'
                - Name: msg
                  Value: '"Drop HTTP cleartext traffic"'

  FirewallPolicy:
    Type: AWS::NetworkFirewall::FirewallPolicy
    Properties:
      FirewallPolicyName: !Sub 'inspection-policy-${Environment}'
      FirewallPolicy:
        StatelessDefaultActions:
          - 'aws:forward_to_sfe'
        StatelessFragmentDefaultActions:
          - 'aws:forward_to_sfe'
        StatefulRuleGroupReferences:
          - ResourceArn: !Ref FirewallRuleGroup

  NetworkFirewall:
    Type: AWS::NetworkFirewall::Firewall
    Properties:
      FirewallName: !Sub 'inspection-fw-${Environment}'
      FirewallPolicyArn: !Ref FirewallPolicy
      VpcId: !Ref HubVPC
      SubnetMappings:
        - SubnetId: !Ref InspectionSubnet

  # 4. Spoke VPC 1 (App VPC)
  SpokeVPC1:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.1.0.0/16
      EnableDnsHostnames: true
      EnableDnsSupport: true
      Tags:
        - Key: Name
          Value: !Sub 'spoke-vpc1-${Environment}'

  Spoke1AppSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref SpokeVPC1
      CidrBlock: 10.1.1.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'spoke1-app-subnet-${Environment}'

  Spoke1TgwSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref SpokeVPC1
      CidrBlock: 10.1.2.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'spoke1-tgw-subnet-${Environment}'

  # 5. Spoke VPC 2 (Db VPC)
  SpokeVPC2:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.2.0.0/16
      EnableDnsHostnames: true
      EnableDnsSupport: true
      Tags:
        - Key: Name
          Value: !Sub 'spoke-vpc2-${Environment}'

  Spoke2DbSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref SpokeVPC2
      CidrBlock: 10.2.1.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'spoke2-db-subnet-${Environment}'

  Spoke2TgwSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref SpokeVPC2
      CidrBlock: 10.2.2.0/24
      AvailabilityZone: !Select [0, !GetAZs '']
      Tags:
        - Key: Name
          Value: !Sub 'spoke2-tgw-subnet-${Environment}'

  # 6. Transit Gateway Attachments
  HubAttachment:
    Type: AWS::EC2::TransitGatewayAttachment
    Properties:
      TransitGatewayId: !Ref TransitGateway
      VpcId: !Ref HubVPC
      SubnetIds:
        - !Ref TgwSubnet
      Tags:
        - Key: Name
          Value: !Sub 'hub-tgw-attachment-${Environment}'

  Spoke1Attachment:
    Type: AWS::EC2::TransitGatewayAttachment
    Properties:
      TransitGatewayId: !Ref TransitGateway
      VpcId: !Ref SpokeVPC1
      SubnetIds:
        - !Ref Spoke1TgwSubnet
      Tags:
        - Key: Name
          Value: !Sub 'spoke1-tgw-attachment-${Environment}'

  Spoke2Attachment:
    Type: AWS::EC2::TransitGatewayAttachment
    Properties:
      TransitGatewayId: !Ref TransitGateway
      VpcId: !Ref SpokeVPC2
      SubnetIds:
        - !Ref Spoke2TgwSubnet
      Tags:
        - Key: Name
          Value: !Sub 'spoke2-tgw-attachment-${Environment}'

  # 7. Transit Gateway Routing Associations & Propagations
  Spoke1Association:
    Type: AWS::EC2::TransitGatewayRouteTableAssociation
    Properties:
      TransitGatewayRouteTableId: !Ref SpokeRouteTable
      TransitGatewayAttachmentId: !Ref Spoke1Attachment

  Spoke2Association:
    Type: AWS::EC2::TransitGatewayRouteTableAssociation
    Properties:
      TransitGatewayRouteTableId: !Ref SpokeRouteTable
      TransitGatewayAttachmentId: !Ref Spoke2Attachment

  HubAssociation:
    Type: AWS::EC2::TransitGatewayRouteTableAssociation
    Properties:
      TransitGatewayRouteTableId: !Ref HubRouteTable
      TransitGatewayAttachmentId: !Ref HubAttachment

  # Propagate routes so Spoke traffic routes back
  Spoke1Propagation:
    Type: AWS::EC2::TransitGatewayRouteTablePropagation
    Properties:
      TransitGatewayRouteTableId: !Ref HubRouteTable
      TransitGatewayAttachmentId: !Ref Spoke1Attachment

  Spoke2Propagation:
    Type: AWS::EC2::TransitGatewayRouteTablePropagation
    Properties:
      TransitGatewayRouteTableId: !Ref HubRouteTable
      TransitGatewayAttachmentId: !Ref Spoke2Attachment

  # Route from Spokes to Hub (Default Egress via Hub Inspection)
  SpokeDefaultRoute:
    Type: AWS::EC2::TransitGatewayRoute
    Properties:
      TransitGatewayRouteTableId: !Ref SpokeRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      TransitGatewayAttachmentId: !Ref HubAttachment

Outputs:
  TransitGatewayId:
    Description: Transit Gateway ID
    Value: !Ref TransitGateway
    Export:
      Name: !Sub '${AWS::StackName}-TGW-ID'

  InspectionFWName:
    Description: Network Firewall Name
    Value: !Ref NetworkFirewall
    Export:
      Name: !Sub '${AWS::StackName}-FW-Name'