Example - Nested stack: VPC stack template

AWSTemplateFormatVersion: "2010-09-09"

Description: AWS CloudFormation workshop - Nested stacks - VPC template.

Parameters:
  AvailabilityZones:
    Type: List<AWS::EC2::AvailabilityZone::Name>
    Description: The list of Availability Zones to use for the subnets in the VPC.

  VPCName:
    Type: String
    Description: The name of the VPC.

  VPCCidr:
    Type: String
    Description: The CIDR block for the VPC.
    AllowedPattern: ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))$
    ConstraintDescription: CIDR block parameter must be in the form x.x.x.x/16-28

  PublicSubnet1Cidr:
    Type: String
    Description: The CIDR block for the public subnet located in Availability Zone 1.
    AllowedPattern: ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))$
    ConstraintDescription: CIDR block parameter must be in the form x.x.x.x/16-28

  PublicSubnet2Cidr:
    Type: String
    Description: The CIDR block for the public subnet located in Availability Zone 2.
    AllowedPattern: ^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/([0-9]|[1-2][0-9]|3[0-2]))$
    ConstraintDescription: CIDR block parameter must be in the form x.x.x.x/16-28

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: !Ref VPCCidr
      EnableDnsHostnames: true
      EnableDnsSupport: true
      InstanceTenancy: default
      Tags:
        - Key: Name
          Value: !Ref VPCName

  VPCPublicSubnet1:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: !Ref PublicSubnet1Cidr
      VpcId: !Ref VPC
      AvailabilityZone: !Select [0, !Ref AvailabilityZones]
      MapPublicIpOnLaunch: true
      Tags:
        - Key: Name
          Value: PublicSubnet1
        - Key: subnet-type
          Value: Public

  VPCPublicSubnet1RouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
        - Key: Name
          Value: PublicSubnet1

  VPCPublicSubnet1RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId:
        Ref: VPCPublicSubnet1RouteTable
      SubnetId:
        Ref: VPCPublicSubnet1

  VPCPublicSubnet1DefaultRoute:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId:
        Ref: VPCPublicSubnet1RouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId:
        Ref: VPCIGW
    DependsOn:
      - VPCGW

  VPCPublicSubnet2:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: !Ref PublicSubnet2Cidr
      VpcId: !Ref VPC
      AvailabilityZone: !Select [1, !Ref AvailabilityZones]
      MapPublicIpOnLaunch: true
      Tags:
        - Key: Name
          Value: PublicSubnet2
        - Key: subnet-type
          Value: Public

  VPCPublicSubnet2RouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
        - Key: Name
          Value: PublicSubnet2

  VPCPublicSubnet2RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId:
        Ref: VPCPublicSubnet2RouteTable
      SubnetId:
        Ref: VPCPublicSubnet2

  VPCPublicSubnet2DefaultRoute:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref VPCPublicSubnet2RouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref VPCIGW
    DependsOn:
      - VPCGW

  VPCIGW:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
        - Key: Name
          Value: VPCIGW

  VPCGW:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId:
        Ref: VPC
      InternetGatewayId:
        Ref: VPCIGW

Outputs:
  VpcId:
    Value: !Ref VPC

  PublicSubnet1:
    Value: !Ref VPCPublicSubnet1

  PublicSubnet2:
    Value: !Ref VPCPublicSubnet2