Ejemplos de Fn::ForEach en la sección Resources

Estos ejemplos son una demostración del uso de la función intrínseca Fn::ForEach en la sección Recursos.

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.

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

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 “{ResourceType}${Identifier}”. Puede declarar varios tipos de recursos en un bucle Fn::ForEach para utilizar un único identificador.

nota

En el ejemplo siguiente se supone que existen las condiciones TwoNatGateways y ThreeNatGateways y que están definidos los recursos PublicSubnetA, PublicSubnetB y PublicSubnetC.

nota

Los valores únicos de cada elemento de la colección se definen en la sección de asignaciones, 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",
  "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

La plantilla transformada será equivalente a la plantilla siguiente:

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

Replicación de varios recursos mediante bucles Fn::ForEach anidados

En este ejemplo se usan 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 AWS::EC2::Instance replicados.

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