nat.yml

---

Description: NAT setup. Original from https://github.com/ansible-city/aws_foundation
AWSTemplateFormatVersion: '2010-09-09'

Parameters:
  AvailabilityZonesCount:
    Description: Number of availabilty zones to use
    Type: Number
    AllowedValues:
      - 1
      - 2
      - 3

  Environment:
    Description: Environment name
    Type: String

Conditions:
  SecondZone:
    Fn::Or:
      - Fn::Equals:
        - Ref: AvailabilityZonesCount
        - 2
      - Fn::Equals:
        - Ref: AvailabilityZonesCount
        - 3
  ThirdZone:
    Fn::Equals:
      - Ref: AvailabilityZonesCount
      - 3

Resources:
  ##
  # NAT for private subnet A
  NatA:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId:
        Fn::ImportValue: !Sub "${Environment}-nat-eip::EipAAllocationId"
      SubnetId:
        Fn::Select:
          - 0
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::SubnetsPublic"

  NatARouteA:
    Type: AWS::EC2::Route
    Properties:
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId:
        Ref: NatA
      RouteTableId:
        Fn::Select:
          - 0
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::RouteTablesPrivate"

  NatB:
    Condition: SecondZone
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId:
        Fn::ImportValue:
          Fn::Sub: "${Environment}-nat-eip::EipBAllocationId"
      SubnetId:
        Fn::Select:
          - 1
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::SubnetsPublic"

  NatBRouteB:
    Condition: SecondZone
    Type: AWS::EC2::Route
    Properties:
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId:
        Ref: NatB
      RouteTableId:
        Fn::Select:
          - 1
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::RouteTablesPrivate"

  NatC:
    Condition: ThirdZone
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId:
        Fn::ImportValue:
          Fn::Sub: "${Environment}-nat-eip::EipCAllocationId"
      SubnetId:
        Fn::Select:
          - 2
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::SubnetsPublic"

  NatCRouteC:
    Condition: ThirdZone
    Type: AWS::EC2::Route
    Properties:
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId:
        Ref: NatC
      RouteTableId:
        Fn::Select:
          - 2
          - Fn::Split:
              - ","
              - Fn::ImportValue: !Sub "${Environment}-vpc::RouteTablesPrivate"