CloudFormation: 2 instances with Docker

AWSTemplateFormatVersion: "2010-09-09"
Metadata:
  License: Apache-2.0
Description: "Create an AWS EC2 instance running the AWS Linux AMI."
Parameters:
  KeyName:
    Description: Name of an existing EC2 KeyPair
    Type: AWS::EC2::KeyPair::KeyName
    ConstraintDescription: must be the name of an existing EC2 KeyPair.

Resources:
  Docker01:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.micro
      SecurityGroups: [!Ref "InstanceSecurityGroup"]
      KeyName: !Ref "KeyName"
      ImageId: ami-0aeeebd8d2ab47354   # us-east-1
      UserData:
        !Base64 |
          #!/bin/bash -xe
          amazon-linux-extras install -y docker=latest
          systemctl enable --now docker.service
          curl -s https://raw.githubusercontent.com/docker/docker-ce/master/components/cli/contrib/completion/bash/docker -o /etc/bash_completion.d/docker.sh
          usermod -a -G docker ec2-user
      Tags:
      - Key: Name
        Value: docker-01

  Docker02:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: t2.micro
      SecurityGroups: [!Ref "InstanceSecurityGroup"]
      KeyName: !Ref "KeyName"
      ImageId: ami-0aeeebd8d2ab47354   # us-east-1
      UserData:
        !Base64 |
          #!/bin/bash -xe
          amazon-linux-extras install -y docker=latest
          systemctl enable --now docker.service
          curl -s https://raw.githubusercontent.com/docker/docker-ce/master/components/cli/contrib/completion/bash/docker -o /etc/bash_completion.d/docker.sh
          usermod -a -G docker ec2-user
      Tags:
      - Key: Name
        Value: docker-02

  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Enable SSH access on port 22
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 22
          ToPort: 22
          CidrIp: "0.0.0.0/0"

Outputs:
  PublicDNS01:
    Description: Public DNS Name of the newly created AWS EC2 instance
    Value: !GetAtt [Docker01, PublicDnsName]
  PublicIP01:
    Description: Public IP address of the newly created AWS EC2 instance
    Value: !GetAtt [Docker01, PublicIp]
  PublicDNS02:
    Description: Public DNS Name of the newly created AWS EC2 instance
    Value: !GetAtt [Docker02, PublicDnsName]
  PublicIP02:
    Description: Public IP address of the newly created AWS EC2 instance
    Value: !GetAtt [Docker02, PublicIp]