Ejemplos de Fn::ForEach en la sección Resources - AWS CloudFormation
Replicación de un recurso de Amazon SNSReplicación de un recurso de Amazon DynamoDBReplicación de varios recursosReplicación de varios recursos mediante bucles Fn::ForEach anidadosReferencia a propiedades replicadas para un recurso de Amazon EC2Replicación de propiedades de un recurso de Amazon EC2Transferencia de caracteres no alfanuméricos en Collection para Fn::ForEach

Esta es la nueva Guía de referencia de plantillas de CloudFormation. Actualice sus marcadores y enlaces. Para obtener ayuda sobre cómo empezar a usar CloudFormation, consulte la Guía del usuario de AWS CloudFormation.

Ejemplos de Fn::ForEach en la sección Resources

Estos ejemplos son una demostración del uso de la función intrínseca Fn::ForEach en la sección Resources. Para obtener más información sobre esta sección, consulte Recursos en la Guía del usuario de AWS CloudFormation.

Replicación de un recurso de Amazon SNS

Este fragmento de ejemplo muestra una lista de cuatro temas de Amazon SNS, con el ID lógico correspondiente a los elementos de la colección (Success, Failure, Timeout, Unknown), con un valor de TopicName coincidente y FifoTopic establecido en true.

nota

Para las plantillas que necesitan funcionar con temas estándar y FIFO, puede utilizar la propiedad DisplayName en lugar de TopicName. Esto permite a CloudFormation generar automáticamente los nombres de los temas con el sufijo .fifo correspondiente cuando FifoTopic sea true. Simplemente reemplace TopicName con DisplayName: !Ref TopicName en la sección Properties.

JSON

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Transform": "AWS::LanguageExtensions",
    "Resources": {
        "Fn::ForEach::Topics": [
            "TopicName",
            ["Success", "Failure", "Timeout", "Unknown"],
            {
                "SnsTopic${TopicName}": {
                    "Type": "AWS::SNS::Topic",
                    "Properties": {
                        "TopicName": {"Fn::Sub": "${TopicName}.fifo"},
                        "FifoTopic": true
                    }
                }
            }
        ]
    }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Resources:
  'Fn::ForEach::Topics':
    - TopicName
    - [Success, Failure, Timeout, Unknown]
    - 'SnsTopic${TopicName}':
        Type: 'AWS::SNS::Topic'
        Properties:
          TopicName: !Sub '${TopicName}.fifo'
          FifoTopic: true

La plantilla transformada será equivalente a la plantilla siguiente:

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

Replicación de un recurso de Amazon DynamoDB

En este fragmento de ejemplo se crean cuatro recursos AWS::DynamoDB::Table con nombres como 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'

La plantilla transformada será equivalente a la plantilla siguiente:

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'

Replicación de varios recursos

En este ejemplo se crean varias instancias de AWS::EC2::NatGateway y AWS::EC2::EIP con la convención de nomenclatura de "{ResourceType}${Identifier}". Puede declarar varios tipos de recursos en un bucle Fn::ForEach para utilizar un único identificador.

Los valores únicos de cada elemento de la colección se definen en la sección Mappings, donde se usa la función intrínseca Fn::FindInMap para hacer referencia al valor correspondiente. Si Fn::FindInMap no puede encontrar el identificador correspondiente, la propiedad Condition no se establecerá y se resolverá en !Ref AWS:::NoValue.

JSON

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Conditions": {
    "TwoNatGateways": {"Fn::Equals": [{"Ref": "AWS::Region"}, "us-east-1"]},
    "ThreeNatGateways": {"Fn::Equals": [{"Ref": "AWS::Region"}, "us-west-2"]}
  },
  "Mappings": {
    "NatGateway": {
      "Condition": {
        "B": "TwoNatGateways",
        "C": "ThreeNatGateways"
      }
    }
  },
  "Resources": {
    "VPC": {
      "Type": "AWS::EC2::VPC",
      "Properties": {"CidrBlock": "10.0.0.0/16"}
    },
    "PublicSubnetA": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "VpcId": {"Ref": "VPC"},
        "CidrBlock": "10.0.1.0/24",
        "AvailabilityZone": {"Fn::Select": [0, {"Fn::GetAZs": ""}]}
      }
    },
    "PublicSubnetB": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "VpcId": {"Ref": "VPC"},
        "CidrBlock": "10.0.2.0/24",
        "AvailabilityZone": {"Fn::Select": [1, {"Fn::GetAZs": ""}]}
      }
    },
    "PublicSubnetC": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "VpcId": {"Ref": "VPC"},
        "CidrBlock": "10.0.3.0/24",
        "AvailabilityZone": {"Fn::Select": [2, {"Fn::GetAZs": ""}]}
      }
    },
    "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
Conditions:
  TwoNatGateways: !Equals [!Ref "AWS::Region", "us-east-1"]
  ThreeNatGateways: !Equals [!Ref "AWS::Region", "us-west-2"]
Mappings:
  NatGateway:
    Condition:
      B: TwoNatGateways
      C: ThreeNatGateways
Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
  PublicSubnetA:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.1.0/24
      AvailabilityZone: !Select [0, !GetAZs ""]
  PublicSubnetB:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.2.0/24
      AvailabilityZone: !Select [1, !GetAZs ""]
  PublicSubnetC:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.3.0/24
      AvailabilityZone: !Select [2, !GetAZs ""]
  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

La plantilla transformada será equivalente a la plantilla siguiente:

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Conditions:
  TwoNatGateways: !Equals [!Ref "AWS::Region", "us-east-1"]
  ThreeNatGateways: !Equals [!Ref "AWS::Region", "us-west-2"]
Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
  PublicSubnetA:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.1.0/24
      AvailabilityZone: !Select [0, !GetAZs ""]
  PublicSubnetB:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.2.0/24
      AvailabilityZone: !Select [1, !GetAZs ""]
  PublicSubnetC:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.3.0/24
      AvailabilityZone: !Select [2, !GetAZs ""]
  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

Replicación de varios recursos mediante bucles Fn::ForEach anidados

En este ejemplo se utilizan bucles Fn::ForEach anidados para asignar tres recursos (AWS::EC2::NetworkAcl, AWS::EC2::Subnet y AWS::EC2::SubnetNetworkAclAssociation) entre sí.

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'

La plantilla transformada será equivalente a la plantilla siguiente:

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

Referencia a propiedades replicadas para un recurso de Amazon EC2

En este ejemplo se usa la función intrínseca Fn::ForEach para hacer referencia a recursos replicados AWS::EC2::Instance.

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]

La plantilla transformada será equivalente a la plantilla siguiente:

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]

Replicación de propiedades de un recurso de Amazon EC2

En este ejemplo se usa la función intrínseca Fn::ForEach para repetir algunas propiedades como ImageId, InstanceType y AvailabilityZone en un recurso 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'}

La plantilla transformada será equivalente a la plantilla siguiente:

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

Transferencia de caracteres no alfanuméricos en Collection para Fn::ForEach

En este ejemplo, se utiliza la sintaxis &{}, que permite que los caracteres no alfanuméricos (. y /) de las direcciones IP se pasen dentro de Collection.

JSON

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Transform": "AWS::LanguageExtensions",
    "Parameters": {
        "IpAddresses": {
            "Type": "CommaDelimitedList",
            "Default": "10.0.2.0/24,10.0.3.0/24,10.0.4.0/24"
        }
    },
    "Resources": {
        "VPC": {
            "Type": "AWS::EC2::VPC",
            "Properties": {
                "CidrBlock": "10.0.0.0/16",
                "EnableDnsSupport": "true",
                "EnableDnsHostnames": "true"
            }
        },
        "Fn::ForEach::Subnets": [
            "CIDR",
            {
                "Ref": "IpAddresses"
            },
            {
                "Subnet&{CIDR}": {
                    "Type": "AWS::EC2::Subnet",
                    "Properties": {
                        "VpcId": {
                            "Ref": "VPC"
                        },
                        "CidrBlock": {
                            "Ref": "CIDR"
                        }
                    }
                }
            }
        ]
    }
}

YAML

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Parameters:
  IpAddresses:
    Type: CommaDelimitedList
    Default: '10.0.2.0/24,10.0.3.0/24,10.0.4.0/24'
Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: 'true'
      EnableDnsHostnames: 'true'
  'Fn::ForEach::Subnets':
    - CIDR
    - !Ref IpAddresses
    - 'Subnet&{CIDR}':
        Type: 'AWS::EC2::Subnet'
        Properties:
          VpcId: !Ref VPC
          CidrBlock: !Ref CIDR

La plantilla transformada será equivalente a la plantilla siguiente:

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Parameters:
  IpAddresses:
    Type: CommaDelimitedList
    Default: '10.0.2.0/24,10.0.3.0/24,10.0.4.0/24'
Resources:
  VPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: 'true'
      EnableDnsHostnames: 'true'
  Subnet1002024:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.2.0/24
  Subnet1003024:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.3.0/24
  Subnet1004024:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref VPC
      CidrBlock: 10.0.4.0/24