Exemples de Fn::ForEach dans la section consacrée aux Resources - AWS CloudFormation
Répliquer une ressource Amazon SNSRépliquer une ressource Amazon DynamoDBRépliquer plusieurs ressourcesRépliquer plusieurs ressources à l'aide de boucles Fn::ForEach imbriquéesRéférencer les propriétés répliquées d'une ressource Amazon EC2Répliquer les propriétés d'une ressource Amazon EC2

Les traductions sont fournies par des outils de traduction automatique. En cas de conflit entre le contenu d'une traduction et celui de la version originale en anglais, la version anglaise prévaudra.

Exemples de Fn::ForEach dans la section consacrée aux Resources

Ces exemples illustrent l'utilisation de la fonction intrinsèque Fn::ForEach dans la section Resources référence de syntaxe de section pour les CloudFormation modèles.

Répliquer une ressource Amazon SNS

Cet exemple d'extrait de code renvoie une liste de quatre rubriques Amazon SNS, avec l'ID logique correspondant aux éléments de la collection (Success, Failure, Timeout, Unknown) et avec des correspondances TopicName et FifoTopic définies sur true.

JSON

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Transform": "AWS::LanguageExtensions",
    "Parameters": {
        "pRepoARNs": {
            "Description": "ARN of SSO instance",
            "Type": "CommaDelimitedList"
        }
    },
    "Resources": {
        "Fn::ForEach::Topics": [
            "TopicName",
            {
                "Ref": "pRepoARNs"
            },
            {
                "SnsTopic${TopicName}": {
                    "Type": "AWS::SNS::Topic",
                    "Properties": {
                        "TopicName": {
                            "Fn::Join": [
                                ".",
                                [
                                    {
                                        "Ref": "TopicName"
                                    },
                                    "fifo"
                                ]
                            ]
                        },
                        "FifoTopic": true
                    }
                }
            }
        ]
    }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Parameters:
  pRepoARNs:
    Description: ARN of SSO instance
    Type: CommaDelimitedList
Resources:
  'Fn::ForEach::Topics':
    - TopicName
    - !Ref pRepoARNs
    - 'SnsTopic${TopicName}':
        Type: 'AWS::SNS::Topic'
        Properties:
          TopicName: 
           'Fn::Join':
            - '.'
            - - !Ref TopicName
              - fifo
          FifoTopic: true

Le modèle transformé sera équivalent au modèle suivant :

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Resources": {
        "SnsTopicSuccess": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "TopicName": "Success.fifo",
                "FifoTopic": true
            }
        },
        "SnsTopicFailure": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "TopicName": "Failure.fifo",
                "FifoTopic": true
            }
        },
        "SnsTopicTimeout": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "TopicName": "Timeout.fifo",
                "FifoTopic": true
            }
        },
        "SnsTopicUnknown": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "TopicName": "Unknown.fifo",
                "FifoTopic": true
            }
        }
    }
}

Répliquer une ressource Amazon DynamoDB

Cet exemple d'extrait de code crée quatre ressources AWS::DynamoDB::Table dotées de noms tels que Points, Score, etc.

JSON

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Transform": "AWS::LanguageExtensions",
    "Resources": {
        "Fn::ForEach::Tables": [
            "TableName",
            ["Points", "Score", "Name", "Leaderboard"],
            {
                "DynamoDB${TableName}": {
                    "Type": "AWS::DynamoDB::Table",
                    "Properties": {
                        "TableName": {
                            "Ref": "TableName"
                        },
                        "AttributeDefinitions": [
                            {
                                "AttributeName": "id",
                                "AttributeType": "S"
                            }
                        ],
                        "KeySchema": [
                            {
                                "AttributeName": "id",
                                "KeyType": "HASH"
                            }
                        ],
                        "ProvisionedThroughput": {
                            "ReadCapacityUnits": "5",
                            "WriteCapacityUnits": "5"
                        }
                    }
                }
            }
        ]
    }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  'Fn::ForEach::Tables':
    - TableName
    - [Points, Score, Name, Leaderboard]
    - 'DynamoDB${TableName}':
        Type: 'AWS::DynamoDB::Table'
        Properties:
          TableName: !Ref TableName
          AttributeDefinitions:
            - AttributeName: id
              AttributeType: S
          KeySchema:
            - AttributeName: id
              KeyType: HASH
          ProvisionedThroughput:
            ReadCapacityUnits: '5'
            WriteCapacityUnits: '5'

Le modèle transformé sera équivalent au modèle suivant :

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  DynamoDBPoints:
    Type: 'AWS::DynamoDB::Table'
    Properties:
      TableName: Points
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      ProvisionedThroughput:
        ReadCapacityUnits: '5'
        WriteCapacityUnits: '5'
  DynamoDBScore:
    Type: 'AWS::DynamoDB::Table'
    Properties:
      TableName: Score
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      ProvisionedThroughput:
        ReadCapacityUnits: '5'
        WriteCapacityUnits: '5'
  DynamoDBName:
    Type: 'AWS::DynamoDB::Table'
    Properties:
      TableName: Name
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      ProvisionedThroughput:
        ReadCapacityUnits: '5'
        WriteCapacityUnits: '5'
  DynamoDBLeaderboard:
    Type: 'AWS::DynamoDB::Table'
    Properties:
      TableName: Leaderboard
      AttributeDefinitions:
        - AttributeName: id
          AttributeType: S
      KeySchema:
        - AttributeName: id
          KeyType: HASH
      ProvisionedThroughput:
        ReadCapacityUnits: '5'
        WriteCapacityUnits: '5'

Répliquer plusieurs ressources

Cet exemple crée plusieurs instances de AWS::EC2::NatGatewayet AWS::EC2::EIPutilise une convention de dénomination de « {ResourceType} $ {Identifier} ». Vous pouvez déclarer plusieurs types de ressources dans une seule boucle Fn::ForEach pour tirer parti d'un identifiant unique.

Note

L'exemple suivant suppose que les conditions TwoNatGateways et ThreeNatGateways existent, et que les ressources PublicSubnetA, PublicSubnetB et PublicSubnetC sont définies.

Note

Des valeurs uniques pour chaque élément de la collection sont définies dans la section Mappages, où la fonction intrinsèque Fn::FindInMap est utilisée pour faire référence à la valeur correspondante. Si la fonction Fn::FindInMap ne parvient pas à trouver l'identifiant correspondant, la propriété Condition ne sera pas définie pour résoudre !Ref ‘AWS:::NoValue.

JSON

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Mappings": {
    "NatGateway": {
      "Condition": {
        "B": "TwoNatGateways",
        "C": "ThreeNatGateways"
      }
    }
  },
  "Resources": {
    "Fn::ForEach::NatGatewayAndEIP": [
      "Identifier",
      [ "A", "B", "C" ],
      {
        "NatGateway${Identifier}": {
          "Type": "AWS::EC2::NatGateway",
          "Properties": {
            "AllocationId": {
              "Fn::GetAtt": [
                {
                  "Fn::Sub": "NatGatewayAttachment${Identifier}"
                },
                "AllocationId"
              ]
            },
            "SubnetId": {
              "Ref": {
                "Fn::Sub": "PublicSubnet${Identifier}"
              }
            }
          },
          "Condition": {
            "Fn::FindInMap": [
              "NatGateway",
              "Condition",
              {
                "Ref": "Identifier"
              },
              {
                "DefaultValue": {
                  "Ref": "AWS::NoValue"
                }
              }
            ]
          }
        },
        "NatGatewayAttachment${Identifier}": {
          "Type": "AWS::EC2::EIP",
          "Properties": {
            "Domain": "vpc"
          },
          "Condition": {
            "Fn::FindInMap": [
              "NatGateway",
              "Condition",
              {
                "Ref": "Identifier"
              },
              {
                "DefaultValue": {
                  "Ref": "AWS::NoValue"
                }
              }
            ]
          }
        }
      }
    ]
  }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Mappings:
  NatGateway:
    Condition:
      B: TwoNatGateways
      C: ThreeNatGateways
Resources:
  Fn::ForEach::NatGatewayAndEIP:
    - Identifier
    - - A
      - B
      - C
    - NatGateway${Identifier}:
        Type: AWS::EC2::NatGateway
        Properties:
          AllocationId: !GetAtt
            - !Sub NatGatewayAttachment${Identifier}
            - AllocationId
          SubnetId: !Ref
            Fn::Sub: PublicSubnet${Identifier}
        Condition: !FindInMap
          - NatGateway
          - Condition
          - !Ref Identifier
          - DefaultValue: !Ref AWS::NoValue
      NatGatewayAttachment${Identifier}:
        Type: AWS::EC2::EIP
        Properties:
          Domain: vpc
        Condition: !FindInMap
          - NatGateway
          - Condition
          - !Ref Identifier
          - DefaultValue: !Ref AWS::NoValue

Le modèle transformé sera équivalent au modèle suivant :

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Resources:
  NatGatewayA:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt
        - NatGatewayAttachmentA
        - AllocationId
      SubnetId: !Ref PublicSubnetA
  NatGatewayB:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt
        - NatGatewayAttachmentB
        - AllocationId
      SubnetId: !Ref PublicSubnetB
    Condition: TwoNatGateways
  NatGatewayC:
    Type: AWS::EC2::NatGateway
    Properties:
      AllocationId: !GetAtt
        - NatGatewayAttachmentC
        - AllocationId
      SubnetId: !Ref PublicSubnetC
    Condition: ThreeNatGateways
  NatGatewayAttachmentA:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
  NatGatewayAttachmentB:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
    Condition: TwoNatGateways
  NatGatewayAttachmentC:
    Type: AWS::EC2::EIP
    Properties:
      Domain: vpc
    Condition: ThreeNatGateways

Répliquer plusieurs ressources à l'aide de boucles Fn::ForEach imbriquées

Cet exemple utilise des boucles Fn::ForEach imbriquées pour mapper trois ressources (AWS::EC2::NetworkAcl, AWS::EC2::Subnet et AWS::EC2::SubnetNetworkAclAssociation) entre elles.

JSON

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Resources": {
    "VPC": {
      "Type": "AWS::EC2::VPC",
      "Properties": {
        "CidrBlock": "10.0.0.0/16",
        "EnableDnsSupport": "true",
        "EnableDnsHostnames": "true"
      }
    },
    "Fn::ForEach::SubnetResources": [
      "Prefix",
      [
        "Transit",
        "Public"
      ],
      {
        "Nacl${Prefix}Subnet": {
          "Type": "AWS::EC2::NetworkAcl",
          "Properties": {
            "VpcId": {
              "Ref": "VPC"
            }
          }
        },
        "Fn::ForEach::LoopInner": [
          "Suffix",
          [
            "A",
            "B",
            "C"
          ],
          {
            "${Prefix}Subnet${Suffix}": {
              "Type": "AWS::EC2::Subnet",
              "Properties": {
                "VpcId": {
                  "Ref": "VPC"
                }
              }
            },
            "Nacl${Prefix}Subnet${Suffix}Association": {
              "Type": "AWS::EC2::SubnetNetworkAclAssociation",
              "Properties": {
                "SubnetId": {
                  "Ref": {
                    "Fn::Sub": "${Prefix}Subnet${Suffix}"
                  }
                },
                "NetworkAclId": {
                  "Ref": {
                    "Fn::Sub": "Nacl${Prefix}Subnet"
                  }
                }
              }
            }
          }
        ]
      }
    ]
  }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  VPC:
    Type: 'AWS::EC2::VPC'
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: 'true'
      EnableDnsHostnames: 'true'
  'Fn::ForEach::SubnetResources':
  - Prefix
  - [Transit, Public]
  - 'Nacl${Prefix}Subnet':
      Type: 'AWS::EC2::NetworkAcl'
      Properties:
        VpcId: !Ref 'VPC'
    'Fn::ForEach::LoopInner':
    - Suffix
    - [A, B, C]
    - '${Prefix}Subnet${Suffix}':
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref 'VPC'
      'Nacl${Prefix}Subnet${Suffix}Association':
        Type: 'AWS::EC2::SubnetNetworkAclAssociation'
        Properties:
          SubnetId: !Ref
            'Fn::Sub': '${Prefix}Subnet${Suffix}'
          NetworkAclId: !Ref
            'Fn::Sub': 'Nacl${Prefix}Subnet'

Le modèle transformé sera équivalent au modèle suivant :

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  VPC:
    Type: 'AWS::EC2::VPC'
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: 'true'
      EnableDnsHostnames: 'true'
  NaclTransitSubnet:
    Type: 'AWS::EC2::NetworkAcl'
    Properties:
      VpcId: !Ref VPC
  TransitSubnetA:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclTransitSubnetAAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref TransitSubnetA
      NetworkAclId: !Ref NaclTransitSubnet
  TransitSubnetB:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclTransitSubnetBAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref TransitSubnetB
      NetworkAclId: !Ref NaclTransitSubnet
  TransitSubnetC:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclTransitSubnetCAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref TransitSubnetC
      NetworkAclId: !Ref NaclTransitSubnet
  NaclPublicSubnet:
    Type: 'AWS::EC2::NetworkAcl'
    Properties:
      VpcId: !Ref VPC
  PublicSubnetA:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclPublicSubnetAAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref PublicSubnetA
      NetworkAclId: !Ref NaclPublicSubnet
  PublicSubnetB:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclPublicSubnetBAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref PublicSubnetB
      NetworkAclId: !Ref NaclPublicSubnet
  PublicSubnetC:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref VPC
  NaclPublicSubnetCAssociation:
    Type: 'AWS::EC2::SubnetNetworkAclAssociation'
    Properties:
      SubnetId: !Ref PublicSubnetC
      NetworkAclId: !Ref NaclPublicSubnet

Référencer les propriétés répliquées d'une ressource Amazon EC2

Cet exemple utilise la fonction intrinsèque Fn::ForEach pour faire référence aux ressources AWS::EC2::Instance répliquées.

JSON

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Mappings": {
    "Instances": {
      "InstanceType": {
        "B": "m5.4xlarge",
        "C": "c5.2xlarge"
      },
      "ImageId": {"A": "ami-id1"}
    }
  },
  "Resources": {
    "Fn::ForEach::Instances": [
      "Identifier",
      [
        "A",
        "B",
        "C"
      ],
      {
        "Instance${Identifier}": {
          "Type": "AWS::EC2::Instance",
          "Properties": {
            "InstanceType": {
              "Fn::FindInMap": [
                "Instances",
                "InstanceType",
                {"Ref": "Identifier"},
                {"DefaultValue": "m5.xlarge"}
              ]
            },
            "ImageId": {
              "Fn::FindInMap": [
                "Instances",
                "ImageId",
                {"Ref": "Identifier"},
                {"DefaultValue": "ami-id-default"}
              ]
            }
          }
        }
      }
    ]
  },
  "Outputs": {
    "SecondInstanceId": {
      "Description": "Instance Id for InstanceB",
      "Value": {"Ref": "InstanceB"}
    },
    "SecondPrivateIp": {
      "Description": "Private IP for InstanceB",
      "Value": {
        "Fn::GetAtt": [
          "InstanceB",
          "PrivateIp"
        ]
      }
    }
  }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Mappings:
  Instances:
    InstanceType:
      B: m5.4xlarge
      C: c5.2xlarge
    ImageId:
      A: ami-id1
Resources:
  'Fn::ForEach::Instances':
  - Identifier
  - [A, B, C]
  - 'Instance${Identifier}':
      Type: 'AWS::EC2::Instance'
      Properties:
        InstanceType: !FindInMap [Instances, InstanceType, !Ref 'Identifier', {DefaultValue: m5.xlarge}]
        ImageId: !FindInMap [Instances, ImageId, !Ref 'Identifier', {DefaultValue: ami-id-default}]
Outputs:
  SecondInstanceId:
    Description: Instance Id for InstanceB
    Value: !Ref 'InstanceB'
  SecondPrivateIp:
    Description: Private IP for InstanceB
    Value: !GetAtt [InstanceB, PrivateIp]

Le modèle transformé sera équivalent au modèle suivant :

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  InstanceA:
    Type: 'AWS::EC2::Instance'
    Properties:
      InstanceType: m5.xlarge
      ImageId: ami-id1
  InstanceB:
    Type: 'AWS::EC2::Instance'
    Properties:
      InstanceType: m5.4xlarge
      ImageId: ami-id-default
  InstanceC:
    Type: 'AWS::EC2::Instance'
    Properties:
      InstanceType: c5.2xlarge
      ImageId: ami-id-default
Outputs:
  SecondInstanceId:
    Description: Instance Id for InstanceB
    Value: !Ref InstanceB
  SecondPrivateIp:
    Description: Private IP for InstanceB
    Value: !GetAtt [InstanceB, PrivateIp]

Répliquer les propriétés d'une ressource Amazon EC2

Cet exemple utilise la fonction intrinsèque Fn::ForEach pour répéter certaines propriétés telles que ImageId, InstanceType et AvailabilityZone à une ressource AWS::EC2::Instance.

JSON

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Mappings": {
    "InstanceA": {
      "Properties": {
        "ImageId": "ami-id1",
        "InstanceType": "m5.xlarge"
      }
    },
    "InstanceB": {
      "Properties": {
        "ImageId": "ami-id2"
      }
    },
    "InstanceC": {
      "Properties": {
        "ImageId": "ami-id3",
        "InstanceType": "m5.2xlarge",
        "AvailabilityZone": "us-east-1a"
      }
    }
  },
  "Resources": {
    "Fn::ForEach::Instances": [
      "InstanceLogicalId",
      [ "InstanceA", "InstanceB", "InstanceC" ],
      {
        "${InstanceLogicalId}": {
          "Type": "AWS::EC2::Instance",
          "Properties": {
            "DisableApiTermination": true,
            "UserData": {
              "Fn::Base64": {
                "Fn::Join": [
                  "",
                  [
                    "#!/bin/bash\n",
                    "yum update -y\n",
                    "yum install -y httpd.x86_64\n",
                    "systemctl start httpd.service\n",
                    "systemctl enable httpd.service\n",
                    "echo \"Hello World from $(hostname -f)\" > /var/www/html/index.html\n"
                  ]
                ]
              }
            },
            "Fn::ForEach::Properties": [
              "PropertyName",
              [ "ImageId", "InstanceType", "AvailabilityZone" ],
              {
                "${PropertyName}": {
                  "Fn::FindInMap": [
                    { "Ref": "InstanceLogicalId" },
                    "Properties",
                    { "Ref": "PropertyName"},
                    {
                      "DefaultValue": { "Ref": "AWS::NoValue" }
                    }
                  ]
                }
              }
            ]
          }
        }
      }
    ]
  }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Mappings:
  InstanceA:
    Properties:
      ImageId: ami-id1
      InstanceType: m5.xlarge
  InstanceB:
    Properties:
      ImageId: ami-id2
  InstanceC:
    Properties:
      ImageId: ami-id3
      InstanceType: m5.2xlarge
      AvailabilityZone: us-east-1a
Resources:
  'Fn::ForEach::Instances':
  - InstanceLogicalId
  - [InstanceA, InstanceB, InstanceC]
  - '${InstanceLogicalId}':
      Type: 'AWS::EC2::Instance'
      Properties:
        DisableApiTermination: true
        UserData:
          Fn::Base64: !Sub |
            #!/bin/bash
            yum update -y
            yum install -y httpd.x86_64
            systemctl start httpd.service
            systemctl enable httpd.service
            echo "Hello World from $(hostname -f)" > /var/www/html/index.html
        'Fn::ForEach::Properties':
          - PropertyName
          - [ImageId, InstanceType, AvailabilityZone]
          - '${PropertyName}':
             'Fn::FindInMap':
               - Ref: 'InstanceLogicalId'
               - Properties
               - Ref: 'PropertyName'
               - {DefaultValue: !Ref 'AWS::NoValue'}

Le modèle transformé sera équivalent au modèle suivant :

AWSTemplateFormatVersion: 2010-09-09
Transform: 'AWS::LanguageExtensions'
Resources:
  InstanceA:
    Type: 'AWS::EC2::Instance'
    Properties:
      DisableApiTermination: true
      UserData:
        Fn::Base64: 
          !Sub |
            #!/bin/bash
            yum update -y
            yum install -y httpd.x86_64
            systemctl start httpd.service
            systemctl enable httpd.service
            echo "Hello World from $(hostname -f)" > /var/www/html/index.html
      ImageId: ami-id1
      InstanceType: m5.xlarge
  InstanceB:
    Type: 'AWS::EC2::Instance'
    Properties:
      DisableApiTermination: true
      UserData:
        Fn::Base64: 
          !Sub |
            #!/bin/bash
            yum update -y
            yum install -y httpd.x86_64
            systemctl start httpd.service
            systemctl enable httpd.service
            echo "Hello World from $(hostname -f)" > /var/www/html/index.html
      ImageId: ami-id2
  InstanceC:
    Type: 'AWS::EC2::Instance'
    Properties:
      DisableApiTermination: true
      UserData:
        Fn::Base64: 
          !Sub |
            #!/bin/bash
            yum update -y
            yum install -y httpd.x86_64
            systemctl start httpd.service
            systemctl enable httpd.service
            echo "Hello World from $(hostname -f)" > /var/www/html/index.html
      ImageId: ami-id3
      InstanceType: m5.2xlarge
      AvailabilityZone: us-east-1a