amazon-eks-vpc-private-subnets.yaml

---
AWSTemplateFormatVersion: '2010-09-09'
Description: 'Amazon EKS VPC - Private and Public subnets'

Parameters:

  VpcBlock:
    Type: String
    Default: 50.0.0.0/16
    Description: The CIDR range for the VPC. This should be a valid private (RFC 1918) CIDR range.

  PublicSubnet01Block:
    Type: String
    Default: 50.0.0.0/24
    Description: CidrBlock for public subnet 01 within the VPC

  PublicSubnet02Block:
    Type: String
    Default: 50.0.64.0/24
    Description: CidrBlock for public subnet 02 within the VPC

  PrivateSubnet01Block:
    Type: String
    Default: 50.0.128.0/24
    Description: CidrBlock for private subnet 01 within the VPC

  PrivateSubnet02Block:
    Type: String
    Default: 50.0.192.0/24
    Description: CidrBlock for private subnet 02 within the VPC

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      -
        Label:
          default: "Worker Network Configuration"
        Parameters:
          - VpcBlock
          - PublicSubnet01Block
          - PublicSubnet02Block
          - PrivateSubnet01Block
          - PrivateSubnet02Block

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock:  !Ref VpcBlock
      EnableDnsSupport: true
      EnableDnsHostnames: true
      Tags:
      - Key: Name
        Value: !Sub '${AWS::StackName}-VPC'

  InternetGateway:
    Type: "AWS::EC2::InternetGateway"

  VPCGatewayAttachment:
    Type: "AWS::EC2::VPCGatewayAttachment"
    Properties:
      InternetGatewayId: !Ref InternetGateway
      VpcId: !Ref VPC

  PublicRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
      - Key: Name
        Value: Public Subnets
      - Key: Network
        Value: Public

  PrivateRouteTable01:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
      - Key: Name
        Value: Private Subnet AZ1
      - Key: Network
        Value: Private01

  PrivateRouteTable02:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
      - Key: Name
        Value: Private Subnet AZ2
      - Key: Network
        Value: Private02

  PublicRoute:
    DependsOn: VPCGatewayAttachment
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PublicRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway

  PrivateRoute01:
    DependsOn:
    - VPCGatewayAttachment
    - NatGateway01
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PrivateRouteTable01
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGateway01

  PrivateRoute02:
    DependsOn:
    - VPCGatewayAttachment
    - NatGateway02
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PrivateRouteTable02
      DestinationCidrBlock: 0.0.0.0/0
      NatGatewayId: !Ref NatGateway02

  NatGateway01:
    DependsOn:
    - NatGatewayEIP1
    - PublicSubnet01
    - VPCGatewayAttachment
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt 'NatGatewayEIP1.AllocationId'
      SubnetId: !Ref PublicSubnet01
      Tags:
      - Key: Name
        Value: !Sub '${AWS::StackName}-NatGatewayAZ1'

  NatGateway02:
    DependsOn:
    - NatGatewayEIP2
    - PublicSubnet02
    - VPCGatewayAttachment
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt 'NatGatewayEIP2.AllocationId'
      SubnetId: !Ref PublicSubnet02
      Tags:
      - Key: Name
        Value: !Sub '${AWS::StackName}-NatGatewayAZ2'

  NatGatewayEIP1:
    DependsOn:
    - VPCGatewayAttachment
    Type: 'AWS::EC2::EIP'
    Properties:
      Domain: vpc

  NatGatewayEIP2:
    DependsOn:
    - VPCGatewayAttachment
    Type: 'AWS::EC2::EIP'
    Properties:
      Domain: vpc

  PublicSubnet01:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Subnet 01
    Properties:
      MapPublicIpOnLaunch: true
      AvailabilityZone:
        Fn::Select:
        - '0'
        - Fn::GetAZs:
            Ref: AWS::Region
      CidrBlock:
        Ref: PublicSubnet01Block
      VpcId:
        Ref: VPC
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PublicSubnet01"
      - Key: kubernetes.io/role/elb
        Value: 1

  PublicSubnet02:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Subnet 02
    Properties:
      MapPublicIpOnLaunch: true
      AvailabilityZone:
        Fn::Select:
        - '1'
        - Fn::GetAZs:
            Ref: AWS::Region
      CidrBlock:
        Ref: PublicSubnet02Block
      VpcId:
        Ref: VPC
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PublicSubnet02"
      - Key: kubernetes.io/role/elb
        Value: 1

  PrivateSubnet01:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Subnet 03
    Properties:
      AvailabilityZone:
        Fn::Select:
        - '0'
        - Fn::GetAZs:
            Ref: AWS::Region
      CidrBlock:
        Ref: PrivateSubnet01Block
      VpcId:
        Ref: VPC
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PrivateSubnet01"
      - Key: kubernetes.io/role/internal-elb
        Value: 1

  PrivateSubnet02:
    Type: AWS::EC2::Subnet
    Metadata:
      Comment: Private Subnet 02
    Properties:
      AvailabilityZone:
        Fn::Select:
        - '1'
        - Fn::GetAZs:
            Ref: AWS::Region
      CidrBlock:
        Ref: PrivateSubnet02Block
      VpcId:
        Ref: VPC
      Tags:
      - Key: Name
        Value: !Sub "${AWS::StackName}-PrivateSubnet02"
      - Key: kubernetes.io/role/internal-elb
        Value: 1

  PublicSubnet01RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet01
      RouteTableId: !Ref PublicRouteTable

  PublicSubnet02RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet02
      RouteTableId: !Ref PublicRouteTable

  PrivateSubnet01RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PrivateSubnet01
      RouteTableId: !Ref PrivateRouteTable01

  PrivateSubnet02RouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PrivateSubnet02
      RouteTableId: !Ref PrivateRouteTable02

  ControlPlaneSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Cluster communication with worker nodes
      VpcId: !Ref VPC

Outputs:

  SubnetIds:
    Description: Subnets IDs in the VPC
    Value: !Join [ ",", [ !Ref PublicSubnet01, !Ref PublicSubnet02, !Ref PrivateSubnet01, !Ref PrivateSubnet02 ] ]

  SecurityGroups:
    Description: Security group for the cluster control plane communication with worker nodes
    Value: !Join [ ",", [ !Ref ControlPlaneSecurityGroup ] ]

  VpcId:
    Description: The VPC Id
    Value: !Ref VPC