Parameters:
  KeyName:
    Description: Name of an existing EC2 KeyPair to enable SSH access to the instances. Linked to AWS Parameter
    Type: AWS::EC2::KeyPair::KeyName
    ConstraintDescription: must be the name of an existing EC2 KeyPair.
  SgIngressSshCidr:
    Description: The IP address range that can be used to communicate to the EC2 instances
    Type: String
    MinLength: '9'
    MaxLength: '18'
    Default: 0.0.0.0/0
    AllowedPattern: (\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})/(\d{1,2})
    ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x.
  LatestAmiId:
    Description: (DO NOT CHANGE)
    Type: 'AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>'
    Default: '/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2'
    AllowedValues:
      - /aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2

Resources:
  MyVPC:
    Type: AWS::EC2::VPC
    Properties:
     EnableDnsSupport: true
     EnableDnsHostnames: true
     CidrBlock: 10.0.0.0/16
     Tags:
        - Key: Name
          Value: My-VPC

  MyIGW:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
        - Key: Name
          Value: My-IGW

  MyIGWAttachment:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      InternetGatewayId: !Ref MyIGW
      VpcId: !Ref MyVPC

  MyPublicRT:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref MyVPC
      Tags:
        - Key: Name
          Value: My-Public-RT

  DefaultPublicRoute:
    Type: AWS::EC2::Route
    DependsOn: MyIGWAttachment
    Properties:
      RouteTableId: !Ref MyPublicRT
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref MyIGW

  MyPublicSN:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref MyVPC
      AvailabilityZone: !Select [ 0, !GetAZs '' ]
      CidrBlock: 10.0.0.0/24
      Tags:
        - Key: Name
          Value: My-Public-SN

  MyPublicSNRouteTableAssociation:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      RouteTableId: !Ref MyPublicRT
      SubnetId: !Ref MyPublicSN

  KOPSEC2SG:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: kops ec2 Security Group
      VpcId: !Ref MyVPC
      Tags:
        - Key: Name
          Value: KOPS-EC2-SG
      SecurityGroupIngress:
      - IpProtocol: tcp
        FromPort: '22'
        ToPort: '22'
        CidrIp: !Ref SgIngressSshCidr

  KOPSEC2:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.micro
      ImageId: !Ref LatestAmiId
      KeyName: !Ref KeyName
      Tags:
        - Key: Name
          Value: kops-ec2
      NetworkInterfaces:
        - DeviceIndex: 0
          SubnetId: !Ref MyPublicSN
          GroupSet:
          - !Ref KOPSEC2SG
          AssociatePublicIpAddress: true
          PrivateIpAddress: 10.0.0.10
      UserData:
        Fn::Base64:
          !Sub |
            #!/bin/bash
            hostnamectl --static set-hostname kops-ec2

            # Change Timezone
            ln -sf /usr/share/zoneinfo/Asia/Seoul /etc/localtime

            # Install Packages
            cd /root
            yum -y install tree jq git htop
            curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
            install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl
            curl -Lo kops https://github.com/kubernetes/kops/releases/download/$(curl -s https://api.github.com/repos/kubernetes/kops/releases/latest | grep tag_name | cut -d '"' -f 4)/kops-linux-amd64
            chmod +x kops
            mv kops /usr/local/bin/kops
            curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
            unzip awscliv2.zip
            sudo ./aws/install
            export PATH=/usr/local/bin:$PATH
            source ~/.bash_profile
            complete -C '/usr/local/bin/aws_completer' aws
            ssh-keygen -t rsa -N "" -f /root/.ssh/id_rsa
            echo 'alias vi=vim' >> /etc/profile
            echo 'sudo su -' >> /home/ec2-user/.bashrc
            curl -s https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash
            wget https://github.com/andreazorzetto/yh/releases/download/v0.4.0/yh-linux-amd64.zip
            unzip yh-linux-amd64.zip
            mv yh /usr/local/bin/

Outputs:
  KopsEC2IP:
    Value: !GetAtt KOPSEC2.PublicIp