[CloudFormation] Template to Install Apache on EC2 Launch

Hello, I'm Tomada.
I've been into CloudFormation lately, so I'm sharing a template that uses User Data to initially install Apache on EC2, as introduced in the previous article below.
→How to initially install Apache using UserData when creating EC2

Also, the template introduced in this article is available on GitHub as well.

How to Configure User Data in a Template

When specifying an EC2 resource, you set it by including a property called UserData within the Properties.

In the example below, I have configured an initial script that performs everything from installing Apache to starting it and setting it to start automatically, as well as setting a string in index.html.

  EC2:
    Type: AWS::EC2::Instance
    Properties:
      ...
      UserData:
        Fn::Base64: |
          #!/bin/bash
          yum -y update
          yum -y install httpd
          systemctl start httpd
          systemctl enable httpd
          echo "Apache is runnning by using UserData" > /var/www/html/index.html

What Can Be Created with This Template

• VPC x1
• Subnet x1
• EC2 x1 (Apache running)

Full Template

cf-ec2-userdata-apache-install.yml

AWSTemplateFormatVersion: "2010-09-09"
Description: Provision EC2

Parameters:
  EnvironmentName:
    Description: Name which you can specify the environment by this name
    Type: String
    Default: test-environment
  VpcCIDR:
    Type: String
    Default: 10.0.0.0/16
  PublicSubnetCIDR:
    Type: String
    Default: 10.0.0.0/24
  KeyName:
    Description: The EC2 Key Pair to allow SSH access to the instance
    Type: "AWS::EC2::KeyPair::KeyName"

  MyIP:
    Description: IP address range which is allowed to access this EC2 from it
    Type: String
    Default: 0.0.0.0/0

Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: !Ref VpcCIDR
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName}-VPC

  InternetGateway:
    Type: AWS::EC2::InternetGateway
    Properties:
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName}-InternetGateway

  # Attach InternetGateway to VPC
  AttachGateway:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties:
      VpcId: !Ref VPC
      InternetGatewayId: !Ref InternetGateway

  PublicSubnet:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: ap-northeast-1a
      VpcId: !Ref VPC
      CidrBlock: !Ref PublicSubnetCIDR
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName}-PublicSubnet

  PublicSubnetRouteTable:
    Type: AWS::EC2::RouteTable
    Properties:
      VpcId: !Ref VPC
      Tags:
        - Key: Name
          Value: !Sub ${EnvironmentName}-PublicSubnetRouteTable

  # Routing from PublicSubnet to Internet
  PublicSubnetToInternet:
    Type: AWS::EC2::Route
    Properties:
      RouteTableId: !Ref PublicSubnetRouteTable
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway

  # Associate PublicSubnetRouteTable to PublicSubnet
  AssoPublicSubnetRouteTable:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties:
      SubnetId: !Ref PublicSubnet
      RouteTableId: !Ref PublicSubnetRouteTable

  EC2:
    Type: AWS::EC2::Instance
    Properties:
      # Amazon Linux 2
      ImageId: ami-00d101850e971728d
      KeyName: !Ref KeyName
      InstanceType: t2.micro
      NetworkInterfaces:
        - AssociatePublicIpAddress: "true"
          DeviceIndex: "0"
          SubnetId: !Ref PublicSubnet
          GroupSet:
            - !Ref EC2SecurityGroup
      UserData:
        Fn::Base64: |
          #!/bin/bash
          yum -y update
          yum -y install httpd
          systemctl start httpd
          systemctl enable httpd
          echo "Apache is runnning by using UserData" > /var/www/html/index.html
      Tags:
          - Key: Name
            Value: !Sub ${EnvironmentName}-EC2

  EC2SecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupName: ec2-sg-cf
      GroupDescription: Allow SSH and HTTP access from only MyIP
      VpcId: !Ref VPC
      SecurityGroupIngress:
        # http
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: !Ref MyIP
        # ssh
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: !Ref MyIP

Access Test to the Web Server

When you access the automatically assigned public IP in your browser, you should see that the string specified in the user data is displayed.