nat-gateway.yaml

AWSTemplateFormatVersion: "2010-09-09"

Description: This template creates NAT Gateway in each public subnet

Parameters:
  ExportVpcStackName: 
    Description: the name of the vpc stack that exports values, this value will be enter when create stack in the console (parameters section)
    Type: String

Resources:
# Allocate Elastic IP Address (EIP 1)
  NatGateway1EIP:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
      Tags:
        - Key: Name
          Value: EIP1

# Allocate Elastic IP Address (EIP 2)
  NatGateway2EIP:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
      Tags:
        - Key: Name
          Value: EIP2

# Create Nat Gateway 1 in Public Subnet 1    
  NatGateway1:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt NatGateway1EIP.AllocationId
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PublicSubnet1
      Tags:
        - Key: Name 
          Value: NatGateway in public subnet 1

# Create Nat Gateway 2 in Public Subnet 2    
  NatGateway2:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt NatGateway2EIP.AllocationId
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PublicSubnet2
      Tags:
        - Key: Name 
          Value: NatGateway in public subnet 2

# Create Private Route Table 1 
  PrivateRouteTable1:
    Type: AWS::EC2::RouteTable
    Properties:
      Tags:
        - Key: Name
          Value: Private Route Table 1
      VpcId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-VPC

# Add a route to point internet-bound traffic to Nat Gateway 1      
  PrivateRoute1:
    Type: AWS::EC2::Route
    Properties:
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGateway1
      RouteTableId: !Ref PrivateRouteTable1

# Associate Private Subnet 1 with Private Route Table 1
  PrivateSubnet1RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTable1
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PrivateSubnet1

# Associate Private Subnet 3 with Private Route Table 1
  PrivateSubnet3RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTable1
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PrivateSubnet3

# Create Private Route Table 2
  PrivateRouteTable2:
    Type: AWS::EC2::RouteTable
    Properties:
      Tags:
        - Key: Name
          Value: Private Route Table 2
      VpcId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-VPC

# Add a route to point internet-bound traffic to Nat Gateway 1      
  PrivateRoute2:
    Type: AWS::EC2::Route
    Properties:
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGateway2
      RouteTableId: !Ref PrivateRouteTable2

# Associate Private Subnet 2 with Private Route Table 2
  PrivateSubnet2RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTable2
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PrivateSubnet2

# Associate Private Subnet 4 with Private Route Table 2
  PrivateSubnet4RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref PrivateRouteTable2
      SubnetId: 
        Fn::ImportValue: !Sub ${ExportVpcStackName}-PrivateSubnet4