這是新的 *CloudFormation 範本參考指南*。請更新您的書籤和連結。如需 CloudFormation 入門的說明，請參閱 [AWS CloudFormation 使用者指南](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/Welcome.html)。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# `Outputs` 區段中的 `Fn::ForEach` 範例
<a name="intrinsic-function-reference-foreach-example-outputs"></a>

這些範例會示範如何使用 `Outputs` 區段中的 `Fn::ForEach` 內部函數。如需有關此區段的詳細資訊，請參閱《AWS CloudFormation 使用者指南》**中的[輸出](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/outputs-section-structure.html)。

**Topics**
+ [參考複寫的 `AWS::S3::Bucket` 資源](#intrinsic-function-reference-foreach-example-replicate-outputs)
+ [參考複寫的 `AWS::EC2::Instance` 資源](#intrinsic-function-reference-foreach-example-replicate-conditions)

## 參考複寫的 `AWS::S3::Bucket` 資源
<a name="intrinsic-function-reference-foreach-example-replicate-outputs"></a>

此範例會使用 `Outputs` 區段中的巢狀 `Fn::ForEach` 迴圈，來縮短範本長度。

### JSON
<a name="intrinsic-function-reference-foreach-example-replicate-outputs.json"></a>

```
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Transform": "AWS::LanguageExtensions",
  "Resources": {
    "Fn::ForEach::Buckets": [
      "Identifier",
      [ "A", "B", "C" ],
      {
        "S3Bucket${Identifier}": {
          "Type": "AWS::S3::Bucket",
          "Properties": {
            "AccessControl": "PublicRead",
            "MetricsConfigurations": [
              {
                "Id": {"Fn::Sub": "EntireBucket${Identifier}"}
              }
            ],
            "WebsiteConfiguration": {
              "IndexDocument": "index.html",
              "ErrorDocument": "error.html",
              "RoutingRules": [
                {
                  "RoutingRuleCondition": {
                    "HttpErrorCodeReturnedEquals": "404",
                    "KeyPrefixEquals": "out1/"
                  },
                  "RedirectRule": {
                    "HostName": "ec2-11-22-333-44.compute-1.amazonaws.com",
                    "ReplaceKeyPrefixWith": "report-404/"
                  }
                }
              ]
            }
          },
          "DeletionPolicy": "Retain",
          "UpdateReplacePolicy": "Retain"
        }
      }
    ]
  },
  "Outputs": {
    "Fn::ForEach::BucketOutputs": [
      "Identifier",
      [ "A", "B", "C" ],
      {
        "Fn::ForEach::GetAttLoop": [
          "Property",
          [ "Arn", "DomainName", "WebsiteURL" ],
          {
            "S3Bucket${Identifier}${Property}": {
              "Value": {"Fn::GetAtt": [{"Fn::Sub": "S3Bucket${Identifier}"}, {"Ref": "Property"}]}
            }
          }
        ]
      }
    ]
  }
}
```

### YAML
<a name="intrinsic-function-reference-foreach-example-outputs.yaml"></a>

```
AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Resources:
  'Fn::ForEach::Buckets':
    - Identifier
    - [A, B, C]
    - 'S3Bucket${Identifier}':
        Type: AWS::S3::Bucket
        Properties:
          AccessControl: PublicRead
          MetricsConfigurations:
            - Id: !Sub 'EntireBucket${Identifier}'
          WebsiteConfiguration:
            IndexDocument: index.html
            ErrorDocument: error.html
            RoutingRules:
              - RoutingRuleCondition:
                  HttpErrorCodeReturnedEquals: '404'
                  KeyPrefixEquals: out1/
                RedirectRule:
                  HostName: ec2-11-22-333-44.compute-1.amazonaws.com
                  ReplaceKeyPrefixWith: report-404/
        DeletionPolicy: Retain
        UpdateReplacePolicy: Retain
Outputs:
  'Fn::ForEach::BucketOutputs':
    - Identifier
    - [A, B, C]
    - 'Fn::ForEach::GetAttLoop':
        - Property
        - [Arn, DomainName, WebsiteURL]
        - 'S3Bucket${Identifier}${Property}':
            Value: !GetAtt [!Sub 'S3Bucket${Identifier}', !Ref Property]
```

轉換後範本將等同於下列範本：

```
AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::LanguageExtensions
Resources:
  S3BucketA:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: PublicRead
      MetricsConfigurations:
        - Id: EntireBucketA
      WebsiteConfiguration:
        IndexDocument: index.html
        ErrorDocument: error.html
        RoutingRules:
          - RoutingRuleCondition:
              HttpErrorCodeReturnedEquals: '404'
              KeyPrefixEquals: out1/
            RedirectRule:
              HostName: ec2-11-22-333-44.compute-1.amazonaws.com
              ReplaceKeyPrefixWith: report-404/
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
  S3BucketB:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: PublicRead
      MetricsConfigurations:
        - Id: EntireBucketB
      WebsiteConfiguration:
        IndexDocument: index.html
        ErrorDocument: error.html
        RoutingRules:
          - RoutingRuleCondition:
              HttpErrorCodeReturnedEquals: '404'
              KeyPrefixEquals: out1/
            RedirectRule:
              HostName: ec2-11-22-333-44.compute-1.amazonaws.com
              ReplaceKeyPrefixWith: report-404/
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
  S3BucketC:
    Type: AWS::S3::Bucket
    Properties:
      AccessControl: PublicRead
      MetricsConfigurations:
        - Id: EntireBucketC
      WebsiteConfiguration:
        IndexDocument: index.html
        ErrorDocument: error.html
        RoutingRules:
          - RoutingRuleCondition:
              HttpErrorCodeReturnedEquals: '404'
              KeyPrefixEquals: out1/
            RedirectRule:
              HostName: ec2-11-22-333-44.compute-1.amazonaws.com
              ReplaceKeyPrefixWith: report-404/
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
Outputs:
  S3BucketAArn:
    Value: !GetAtt [S3BucketA, Arn]
  S3BucketADomainName:
    Value: !GetAtt [S3BucketA, DomainName]
  S3BucketAWebsiteURL:
    Value: !GetAtt [S3BucketA, WebsiteURL]
  S3BucketBArn:
    Value: !GetAtt [S3BucketB, Arn]
  S3BucketBDomainName:
    Value: !GetAtt [S3BucketB, DomainName]
  S3BucketBWebsiteURL:
    Value: !GetAtt [S3BucketB, WebsiteURL]
  S3BucketCArn:
    Value: !GetAtt [S3BucketC, Arn]
  S3BucketCDomainName:
    Value: !GetAtt [S3BucketC, DomainName]
  S3BucketCWebsiteURL:
    Value: !GetAtt [S3BucketC, WebsiteURL]
```

## 參考複寫的 `AWS::EC2::Instance` 資源
<a name="intrinsic-function-reference-foreach-example-replicate-conditions"></a>

此範例使用產生的邏輯 ID，在 `Resources` 區段中參考複寫的資源。

### JSON
<a name="intrinsic-function-reference-foreach-example-replicate-conditions.json"></a>

```
{
  "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
<a name="intrinsic-function-reference-foreach-example-replicate-conditions.yaml"></a>

```
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]
```

轉換後範本將等同於下列範本：

```
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]
```