# This creates a VPC with two public subnets and two private subnets in two Availability Zones, 
# together with a NAT Gateway and associated routing. Change the Availability Zone locations as needed.

# Usage from command line:
#   aws cloudformation --region <<YOUR-REGION>> create-stack --stack-name vpc- --template-body file://vpc-setup.yaml
    
    Resources:
      ## VPC
      PubPrivateVPC:
        Type: AWS::EC2::VPC
        Properties:
          CidrBlock: 10.0.0.0/16
          Tags:
            - Key: Name
              Value: PubPrivateVPC

      ## SUBNETS     
      PublicSubnet1:
        Type: AWS::EC2::Subnet
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1a
          CidrBlock: 10.0.1.0/24
          MapPublicIpOnLaunch: true
          Tags:
            - Key: Name
              Value: PublicSubnet1
     
      PublicSubnet2:
        Type: AWS::EC2::Subnet
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1b
          CidrBlock: 10.0.2.0/24
          MapPublicIpOnLaunch: true
          Tags:
            - Key: Name
              Value: PublicSubnet2
     
      PrivateSubnet1:
        Type: AWS::EC2::Subnet
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1a
          CidrBlock: 10.0.3.0/24
          MapPublicIpOnLaunch: false
          Tags:
            - Key: Name
              Value: PrivateSubnet1
     
      PrivateSubnet2:
        Type: AWS::EC2::Subnet
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1b
          CidrBlock: 10.0.4.0/24
          MapPublicIpOnLaunch: false
          Tags:
            - Key: Name
              Value: PrivateSubnet2
     
     ## INTERNET GATEWAY
      InternetGateway:
        Type: AWS::EC2::InternetGateway
      
      GatewayToInternet:
        Type: AWS::EC2::VPCGatewayAttachment
        Properties:
          VpcId: !Ref PubPrivateVPC
          InternetGatewayId: !Ref InternetGateway
      
      ## PUBLIC ROUTING
      PublicRouteTable:
        Type: AWS::EC2::RouteTable
        Properties:
          VpcId: !Ref PubPrivateVPC
      
      PublicRoute:
        Type: AWS::EC2::Route
        DependsOn: GatewayToInternet
        Properties:
          RouteTableId: !Ref PublicRouteTable
          DestinationCidrBlock: 0.0.0.0/0
          GatewayId: !Ref InternetGateway
     
      PublicSubnet1RouteTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
          SubnetId: !Ref PublicSubnet1
          RouteTableId: !Ref PublicRouteTable
     
      PublicSubnet2RouteTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
          SubnetId: !Ref PublicSubnet2
          RouteTableId: !Ref PublicRouteTable
     
      ## NAT GATEWAY
      NatGateway:
        Type: AWS::EC2::NatGateway
        DependsOn: NatPublicIP
        Properties: 
          SubnetId: !Ref PublicSubnet1
          AllocationId: !GetAtt NatPublicIP.AllocationId
          Tags:
            - Key: Name
              Value: NatGateway

      ## ELASTIC IP
      NatPublicIP:
        Type: AWS::EC2::EIP
        DependsOn: PubPrivateVPC
        Properties:
          Domain: vpc
     
      ## PRIVATE ROUTING
      PrivateRouteTable:
        Type: AWS::EC2::RouteTable
        Properties:
          VpcId: !Ref PubPrivateVPC
      
      PrivateRoute:
        Type: AWS::EC2::Route
        Properties:
          NatGatewayId: !Ref NatGateway
          RouteTableId: !Ref PrivateRouteTable
          DestinationCidrBlock: 0.0.0.0/0
     
      PrivateSubnet1RouteTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
          SubnetId: !Ref PrivateSubnet1
          RouteTableId: !Ref PrivateRouteTable
     
      PrivateSubnet2RouteTableAssociation:
        Type: AWS::EC2::SubnetRouteTableAssociation
        Properties:
          SubnetId: !Ref PrivateSubnet2
          RouteTableId: !Ref PrivateRouteTable