Cloudformation template for setting up VPC and subnets for Fargate

vpc-fargate.yaml

    # Usage:
    #   aws cloudformation --region <region> create-stack --stack-name <stack name> --template-body file://vpc-fargate.yaml
    
    # This template will:
    #   Create a VPC with:
    #       2 Public Subnets
    #       2 Private Subnets
    #   An Internet Gateway (with routes to it for Public Subnets)
    #   A NAT Gateway for outbound access (with routes from Private Subnets set to use it)
    #     
    Resources:
      PubPrivateVPC:
        Type: 'AWS::EC2::VPC'
        Properties:
          CidrBlock: 172.31.0.0/16
     
      PublicSubnet1:
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1a
          CidrBlock: 172.31.1.0/24
          MapPublicIpOnLaunch: true
     
      PublicSubnet2:
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1b
          CidrBlock: 172.31.2.0/24
          MapPublicIpOnLaunch: true
     
      PrivateSubnet1:
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1a
          CidrBlock: 172.31.3.0/24
          MapPublicIpOnLaunch: false
     
      PrivateSubnet2:
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref PubPrivateVPC
          AvailabilityZone: us-east-1b
          CidrBlock: 172.31.4.0/24
          MapPublicIpOnLaunch: false
     
      
      InternetGateway:
        Type: 'AWS::EC2::InternetGateway'
        Properties:
          Tags:
            - Key: Name
              Value: !Join [_, [!Ref 'AWS::StackName']]
            - Key: Network
              Value: Public
      
      GatewayToInternet:
        Type: 'AWS::EC2::VPCGatewayAttachment'
        Properties:
          VpcId: !Ref PubPrivateVPC
          InternetGatewayId: !Ref InternetGateway
      
      PublicRouteTable:
        Type: 'AWS::EC2::RouteTable'
        Properties:
          VpcId: !Ref PubPrivateVPC
          Tags:
            - Key: Network
              Value: Public
      
      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
     
      NatGateway:
        Type: "AWS::EC2::NatGateway"
        DependsOn: NatPublicIP
        Properties: 
          AllocationId: !GetAtt NatPublicIP.AllocationId
          SubnetId: !Ref PublicSubnet1
     
      NatPublicIP:
        Type: "AWS::EC2::EIP"
        DependsOn: PubPrivateVPC
        Properties:
          Domain: vpc
     
      PrivateRouteTable:
        Type: 'AWS::EC2::RouteTable'
        Properties:
          VpcId: !Ref PubPrivateVPC
          Tags:
            - Key: Network
              Value: Private
      
      PrivateRoute:
        Type: 'AWS::EC2::Route'
        Properties:
          RouteTableId: !Ref PrivateRouteTable
          DestinationCidrBlock: 0.0.0.0/0
          NatGatewayId: !Ref NatGateway
     
      PrivateSubnet1RouteTableAssociation:
        Type: 'AWS::EC2::SubnetRouteTableAssociation'
        Properties:
          SubnetId: !Ref PrivateSubnet1
          RouteTableId: !Ref PrivateRouteTable
     
      PrivateSubnet2RouteTableAssociation:
        Type: 'AWS::EC2::SubnetRouteTableAssociation'
        Properties:
          SubnetId: !Ref PrivateSubnet2
          RouteTableId: !Ref PrivateRouteTable

The route identified by 0.0.0.0/0 already exists

Every time I am getting this error

You should check if there is no other VPC with that CIDR block in your region.