

기계 번역으로 제공되는 번역입니다. 제공된 번역과 원본 영어의 내용이 상충하는 경우에는 영어 버전이 우선합니다.

# 사용자 지정 CloudFormation 후크 모델링
<a name="hooks-model"></a>

사용자 지정 CloudFormation 후크 모델링에는 후크, 속성 및 속성을 정의하는 스키마를 생성하는 작업이 포함됩니다. `cfn init` 명령을 사용하여 사용자 지정 후크 프로젝트를 생성하면 예제 후크 스키마가 JSON 형식의 텍스트 파일 로 생성됩니다`hook-name.json`.

대상 호출 지점 및 대상 작업은 후크가 호출되는 정확한 지점을 지정합니다. *후크 핸들러*는 이러한 지점에 대한 실행 파일 사용자 지정 로직을 호스팅합니다. 예를 들어 `CREATE` 작업의 대상 작업은 `preCreate` 핸들러를 사용합니다. 핸들러에 작성된 코드는 후크 대상 및 서비스가 일치하는 작업을 수행할 때 호출됩니다. *후크 대상*은 후크가 호출되는 대상입니다. CloudFormation 퍼블릭 리소스, 프라이빗 리소스 또는 사용자 지정 리소스와 같은 대상을 지정할 수 있습니다. 후크는 무제한의 후크 대상을 지원합니다.

스키마에는 후크에 필요한 권한이 포함되어 있습니다. 후크를 작성하려면 각 후크 핸들러에 대한 권한을 지정해야 합니다. CloudFormation은 작성자에게 *최소 권한을* 부여하거나 작업을 수행하는 데 필요한 권한만 부여하는 표준 보안 조언을 따르는 정책을 작성하도록 권장합니다. 사용자(및 역할)가 수행해야 할 작업을 결정한 다음 후크 작업에 대해 해당 작업*만* 수행하도록 허용하는 정책을 생성합니다. CloudFormation은 이러한 권한을 사용하여 후크 사용자가 제공한 권한을 범위 축소합니다. 이러한 권한은 후크로 전달됩니다. 후크 핸들러는 이러한 권한을 사용하여 AWS 리소스에 액세스합니다.

다음 스키마 파일을 시작점으로 사용하여 후크를 정의할 수 있습니다. 후크 스키마를 사용하여 구현할 핸들러를 지정합니다. 특정 핸들러를 구현하지 않도록 선택한 경우 후크 스키마의 핸들러 섹션에서 제거합니다. 스키마에 대한 자세한 내용은 섹션을 참조하세요[스키마 구문](hooks-schema.md).

```
{
    "typeName":"MyCompany::Testing::MyTestHook",
    "description":"Verifies S3 bucket and SQS queues properties before create and update",
    "sourceUrl":"https://mycorp.com/my-repo.git",
    "documentationUrl":"https://mycorp.com/documentation",
    "typeConfiguration":{
        "properties":{
            "minBuckets":{
                "description":"Minimum number of compliant buckets",
                "type":"string"
            },
            "minQueues":{
                "description":"Minimum number of compliant queues",
                "type":"string"
            },
            "encryptionAlgorithm":{
                "description":"Encryption algorithm for SSE",
                "default":"AES256",
                "type":"string"
            }
        },
        "required":[
            
        ],
        "additionalProperties":false
    },
    "handlers":{
        "preCreate":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                
            ]
        },
        "preUpdate":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                
            ]
        },
        "preDelete":{
            "targetNames":[
                "AWS::S3::Bucket",
                "AWS::SQS::Queue"
            ],
            "permissions":[
                "s3:ListBucket",
                "s3:ListAllMyBuckets",
                "s3:GetEncryptionConfiguration",
                "sqs:ListQueues",
                "sqs:GetQueueAttributes",
                "sqs:GetQueueUrl"
            ]
        }
    },
    "additionalProperties":false
}
```

**Topics**
+ [Java를 사용하여 사용자 지정 CloudFormation 후크 모델링](hooks-model-java.md)
+ [Python을 사용하여 사용자 지정 CloudFormation 후크 모델링](hooks-model-python.md)

# Java를 사용하여 사용자 지정 CloudFormation 후크 모델링
<a name="hooks-model-java"></a>

사용자 지정 CloudFormation 후크 모델링에는 후크, 해당 속성 및 속성을 정의하는 스키마를 생성하는 작업이 포함됩니다. 이 자습서에서는 Java를 사용하여 사용자 지정 후크를 모델링하는 방법을 안내합니다.

## 1단계: 프로젝트 종속성 추가
<a name="model-hook-project-dependencies"></a>

Java 기반 후크 프로젝트는 Maven의 `pom.xml` 파일을 종속성으로 사용합니다. 다음 섹션을 확장하고 소스 코드를 프로젝트 루트의 `pom.xml` 파일에 복사합니다.

### 후크 프로젝트 종속성(pom.xml)
<a name="hook-java-dependencies"></a>

```
<?xml version="1.0" encoding="UTF-8"?>
<project
    xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mycompany.testing.mytesthook</groupId>
    <artifactId>mycompany-testing-mytesthook-handler</artifactId>
    <name>mycompany-testing-mytesthook-handler</name>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <aws.java.sdk.version>2.16.1</aws.java.sdk.version>
        <checkstyle.version>8.36.2</checkstyle.version>
        <commons-io.version>2.8.0</commons-io.version>
        <jackson.version>2.11.3</jackson.version>
        <maven-checkstyle-plugin.version>3.1.1</maven-checkstyle-plugin.version>
        <mockito.version>3.6.0</mockito.version>
        <spotbugs.version>4.1.4</spotbugs.version>
        <spotless.version>2.5.0</spotless.version>
        <maven-javadoc-plugin.version>3.2.0</maven-javadoc-plugin.version>
        <maven-source-plugin.version>3.2.1</maven-source-plugin.version>
        <cfn.generate.args/>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>software.amazon.awssdk</groupId>
                <artifactId>bom</artifactId>
                <version>2.16.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/software.amazon.cloudformation/aws-cloudformation-rpdk-java-plugin -->
        <dependency>
            <groupId>software.amazon.cloudformation</groupId>
            <artifactId>aws-cloudformation-rpdk-java-plugin</artifactId>
            <version>[2.0.0,3.0.0)</version>
        </dependency>

        <!-- AWS Java SDK v2 Dependencies -->
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>sdk-core</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>cloudformation</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>s3</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>utils</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>apache-client</artifactId>
        </dependency>
        <dependency>
            <groupId>software.amazon.awssdk</groupId>
            <artifactId>sqs</artifactId>
        </dependency>

        <!-- Test dependency for Java Providers -->
        <dependency>
            <groupId>software.amazon.cloudformation</groupId>
            <artifactId>cloudformation-cli-java-plugin-testing-support</artifactId>
            <version>1.0.0</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-s3 -->
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-java-sdk-s3</artifactId>
            <version>1.12.85</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>${commons-io.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.9</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-collections4 -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-collections4</artifactId>
            <version>4.4</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>29.0-jre</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-cloudformation -->
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-java-sdk-cloudformation</artifactId>
            <version>1.11.555</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/commons-codec/commons-codec -->
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.14</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/software.amazon.cloudformation/aws-cloudformation-resource-schema -->
        <dependency>
            <groupId>software.amazon.cloudformation</groupId>
            <artifactId>aws-cloudformation-resource-schema</artifactId>
            <version>[2.0.5, 3.0.0)</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.dataformat/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.dataformat/jackson-dataformat-cbor -->
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-cbor</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.module/jackson-modules-java8 -->
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-modules-java8</artifactId>
            <version>${jackson.version}</version>
            <type>pom</type>
            <scope>runtime</scope>
        </dependency>

         <!-- https://mvnrepository.com/artifact/org.json/json -->
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20180813</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-core -->
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-java-sdk-core</artifactId>
            <version>1.11.1034</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-lambda-java-core -->
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-core</artifactId>
            <version>1.2.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-lambda-java-log4j2 -->
        <dependency>
            <groupId>com.amazonaws</groupId>
            <artifactId>aws-lambda-java-log4j2</artifactId>
            <version>1.2.0</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.8</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.4</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.17.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.17.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-slf4j-impl -->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j-impl</artifactId>
            <version>2.17.1</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.assertj/assertj-core -->
        <dependency>
            <groupId>org.assertj</groupId>
            <artifactId>assertj-core</artifactId>
            <version>3.12.2</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.5.0-M1</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mockito/mockito-core -->
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>3.6.0</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mockito/mockito-junit-jupiter -->
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-junit-jupiter</artifactId>
            <version>3.6.0</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <compilerArgs>
                        <arg>-Xlint:all,-options,-processing</arg>
                    </compilerArgs>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.3</version>
                <configuration>
                    <createDependencyReducedPom>false</createDependencyReducedPom>
                    <filters>
                        <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                                <exclude>**/Log4j2Plugins.dat</exclude>
                            </excludes>
                        </filter>
                    </filters>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.6.0</version>
                <executions>
                    <execution>
                        <id>generate</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>exec</goal>
                        </goals>
                        <configuration>
                            <executable>cfn</executable>
                            <commandlineArgs>generate ${cfn.generate.args}</commandlineArgs>
                            <workingDirectory>${project.basedir}</workingDirectory>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>build-helper-maven-plugin</artifactId>
                <version>3.0.0</version>
                <executions>
                    <execution>
                        <id>add-source</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>add-source</goal>
                        </goals>
                        <configuration>
                            <sources>
                                <source>${project.basedir}/target/generated-sources/rpdk</source>
                            </sources>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.4</version>
            </plugin>
            <plugin>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>3.0.0-M3</version>
            </plugin>
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
                <version>0.8.4</version>
                <configuration>
                    <excludes>
                        <exclude>**/BaseHookConfiguration*</exclude>
                        <exclude>**/BaseHookHandler*</exclude>
                        <exclude>**/HookHandlerWrapper*</exclude>
                        <exclude>**/ResourceModel*</exclude>
                        <exclude>**/TypeConfigurationModel*</exclude>
                        <exclude>**/model/**/*</exclude>
                    </excludes>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>prepare-agent</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>report</id>
                        <phase>test</phase>
                        <goals>
                            <goal>report</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>jacoco-check</id>
                        <goals>
                            <goal>check</goal>
                        </goals>
                        <configuration>
                            <rules>
                                <rule>
                                    <element>PACKAGE</element>
                                    <limits>
                                        <limit>
                                            <counter>BRANCH</counter>
                                            <value>COVEREDRATIO</value>
                                            <minimum>0.8</minimum>
                                        </limit>
                                        <limit>
                                            <counter>INSTRUCTION</counter>
                                            <value>COVEREDRATIO</value>
                                            <minimum>0.8</minimum>
                                        </limit>
                                    </limits>
                                </rule>
                            </rules>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>${project.basedir}</directory>
                <includes>
                    <include>mycompany-testing-mytesthook.json</include>
                </includes>
            </resource>
            <resource>
                <directory>${project.basedir}/target/loaded-target-schemas</directory>
                <includes>
                    <include>**/*.json</include>
                </includes>
            </resource>
        </resources>
    </build>
</project>
```

## 2단계: 후크 프로젝트 패키지 생성
<a name="model-hook-project-package-java"></a>

후크 프로젝트 패키지를 생성합니다. CloudFormation CLI는 후크 사양에 정의된 대상 수명 주기의 특정 후크 작업에 해당하는 빈 핸들러 함수를 생성합니다.

```
cfn generate
```

명령은 다음 출력을 반환합니다.

```
Generated files for MyCompany::Testing::MyTestHook
```

**참고**  
더 이상 사용되지 않는 버전을 사용하지 않도록 Lambda 런타임이 up-to-date 상태인지 확인합니다. 자세한 내용은 [리소스 유형 및 후크에 대한 Lambda 런타임 업데이트를 참조하세요](https://docs.aws.amazon.com/cloudformation-cli/latest/userguide/runtime-update.html).

## 3단계: 후크 핸들러 추가
<a name="model-hook-project-add-handler-java"></a>

구현하도록 선택한 핸들러에 자체 후크 핸들러 런타임 코드를 추가합니다. 예를 들어 로깅을 위해 다음 코드를 추가할 수 있습니다.

```
logger.log("Internal testing Hook triggered for target: " + request.getHookContext().getTargetName());
```

CloudFormation CLI는 일반 구형 Java 객체(Java POJO)를 생성합니다. 다음은에서 생성된 출력 예제입니다`AWS::S3::Bucket`.

**Example AwsS3BucketTargetModel.java**  

```
package com.mycompany.testing.mytesthook.model.aws.s3.bucket;

import...


@Data
@NoArgsConstructor
@EqualsAndHashCode(callSuper = true)
@ToString(callSuper = true)
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
public class AwsS3BucketTargetModel extends ResourceHookTargetModel<AwsS3Bucket> {

    @JsonIgnore
    private static final TypeReference<AwsS3Bucket> TARGET_REFERENCE =
        new TypeReference<AwsS3Bucket>() {};

    @JsonIgnore
    private static final TypeReference<AwsS3BucketTargetModel> MODEL_REFERENCE =
        new TypeReference<AwsS3BucketTargetModel>() {};

    @JsonIgnore
    public static final String TARGET_TYPE_NAME = "AWS::S3::Bucket";


    @JsonIgnore
    public TypeReference<AwsS3Bucket> getHookTargetTypeReference() {
        return TARGET_REFERENCE;
    }

    @JsonIgnore
    public TypeReference<AwsS3BucketTargetModel> getTargetModelTypeReference() {
        return MODEL_REFERENCE;
    }
}
```

**Example AwsS3Bucket.java**  

```
package com.mycompany.testing.mytesthook.model.aws.s3.bucket;

import ...


@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@EqualsAndHashCode(callSuper = true)
@ToString(callSuper = true)
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
public class AwsS3Bucket extends ResourceHookTarget {
    @JsonIgnore
    public static final String TYPE_NAME = "AWS::S3::Bucket";

    @JsonIgnore
    public static final String IDENTIFIER_KEY_ID = "/properties/Id";

    @JsonProperty("InventoryConfigurations")
    private List<InventoryConfiguration> inventoryConfigurations;

    @JsonProperty("WebsiteConfiguration")
    private WebsiteConfiguration websiteConfiguration;

    @JsonProperty("DualStackDomainName")
    private String dualStackDomainName;

    @JsonProperty("AccessControl")
    private String accessControl;

    @JsonProperty("AnalyticsConfigurations")
    private List<AnalyticsConfiguration> analyticsConfigurations;

    @JsonProperty("AccelerateConfiguration")
    private AccelerateConfiguration accelerateConfiguration;

    @JsonProperty("PublicAccessBlockConfiguration")
    private PublicAccessBlockConfiguration publicAccessBlockConfiguration;

    @JsonProperty("BucketName")
    private String bucketName;

    @JsonProperty("RegionalDomainName")
    private String regionalDomainName;

    @JsonProperty("OwnershipControls")
    private OwnershipControls ownershipControls;

    @JsonProperty("ObjectLockConfiguration")
    private ObjectLockConfiguration objectLockConfiguration;

    @JsonProperty("ObjectLockEnabled")
    private Boolean objectLockEnabled;

    @JsonProperty("LoggingConfiguration")
    private LoggingConfiguration loggingConfiguration;

    @JsonProperty("ReplicationConfiguration")
    private ReplicationConfiguration replicationConfiguration;

    @JsonProperty("Tags")
    private List<Tag> tags;

    @JsonProperty("DomainName")
    private String domainName;

    @JsonProperty("BucketEncryption")
    private BucketEncryption bucketEncryption;

    @JsonProperty("WebsiteURL")
    private String websiteURL;

    @JsonProperty("NotificationConfiguration")
    private NotificationConfiguration notificationConfiguration;

    @JsonProperty("LifecycleConfiguration")
    private LifecycleConfiguration lifecycleConfiguration;

    @JsonProperty("VersioningConfiguration")
    private VersioningConfiguration versioningConfiguration;

    @JsonProperty("MetricsConfigurations")
    private List<MetricsConfiguration> metricsConfigurations;

    @JsonProperty("IntelligentTieringConfigurations")
    private List<IntelligentTieringConfiguration> intelligentTieringConfigurations;

    @JsonProperty("CorsConfiguration")
    private CorsConfiguration corsConfiguration;

    @JsonProperty("Id")
    private String id;

    @JsonProperty("Arn")
    private String arn;

    @JsonIgnore
    public JSONObject getPrimaryIdentifier() {
        final JSONObject identifier = new JSONObject();
        if (this.getId() != null) {
            identifier.put(IDENTIFIER_KEY_ID, this.getId());
        }

        // only return the identifier if it can be used, i.e. if all components are present
        return identifier.length() == 1 ? identifier : null;
    }

    @JsonIgnore
    public List<JSONObject> getAdditionalIdentifiers() {
        final List<JSONObject> identifiers = new ArrayList<JSONObject>();
        // only return the identifiers if any can be used
        return identifiers.isEmpty() ? null : identifiers;
    }
}
```

**Example BucketEncryption.java**  

```
package software.amazon.testing.mytesthook.model.aws.s3.bucket;

import ...


@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
public class BucketEncryption {
    @JsonProperty("ServerSideEncryptionConfiguration")
    private List<ServerSideEncryptionRule> serverSideEncryptionConfiguration;

}
```

**Example ServerSideEncryptionRule.java**  

```
package com.mycompany.testing.mytesthook.model.aws.s3.bucket;

import ...


@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
public class ServerSideEncryptionRule {
    @JsonProperty("BucketKeyEnabled")
    private Boolean bucketKeyEnabled;

    @JsonProperty("ServerSideEncryptionByDefault")
    private ServerSideEncryptionByDefault serverSideEncryptionByDefault;

}
```

**Example ServerSideEncryptionByDefault.java**  

```
package com.mycompany.testing.mytesthook.model.aws.s3.bucket;

import ...


@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE)
public class ServerSideEncryptionByDefault {
    @JsonProperty("SSEAlgorithm")
    private String sSEAlgorithm;

    @JsonProperty("KMSMasterKeyID")
    private String kMSMasterKeyID;

}
```

POJOs 생성되면 이제 후크의 기능을 실제로 구현하는 핸들러를 작성할 수 있습니다. 이 예제에서는 핸들러에 대한 `preCreate` 및 `preUpdate` 호출 지점을 구현합니다.

## 4단계: 후크 핸들러 구현
<a name="model-hook-project-code-handler-java"></a>

**Topics**
+ [API 클라이언트 빌더 코딩](#java-code-api-client-builder)
+ [API 요청 생성자 코딩](#code-the-api-request-maker)
+ [헬퍼 코드 구현](#implement-helper-code)
+ [기본 핸들러 구현](#implement-base-hook-handler)
+ [`preCreate` 핸들러 구현](#implementing-precreate-handler)
+ [`preCreate` 핸들러 코딩](#coding-the-precreate-handler)
+ [`preCreate` 테스트 업데이트](#updating-the-precreate-handler)
+ [`preUpdate` 핸들러 구현](#implementing-preupdate-handler)
+ [`preUpdate` 핸들러 코딩](#coding-preupdate-handler)
+ [`preUpdate` 테스트 업데이트](#update-the-preupdate-handler)
+ [`preDelete` 핸들러 구현](#implement-the-predelete-hander)
+ [`preDelete` 핸들러 코딩](#code-the-predelete-handler)
+ [`preDelete` 핸들러 업데이트](#update-the-predelete-handler)

### API 클라이언트 빌더 코딩
<a name="java-code-api-client-builder"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더에 있는 `ClientBuilder.java` 파일을 엽니다.

1. `ClientBuilder.java` 파일의 전체 내용을 다음 코드로 바꿉니다.  
**Example ClientBuilder.java**  

   ```
   package com.awscommunity.kms.encryptionsettings;
   
   import software.amazon.awssdk.services.ec2.Ec2Client;
   import software.amazon.cloudformation.HookLambdaWrapper;
   
   /**
    * Describes static HTTP clients (to consume less memory) for API calls that
    * this hook makes to a number of AWS services.
    */
   public final class ClientBuilder {
   
       private ClientBuilder() {
       }
   
       /**
        * Create an HTTP client for Amazon EC2.
        *
        * @return Ec2Client An {@link Ec2Client} object.
        */
       public static Ec2Client getEc2Client() {
           return Ec2Client.builder().httpClient(HookLambdaWrapper.HTTP_CLIENT).build();
       }
   }
   ```

### API 요청 생성자 코딩
<a name="code-the-api-request-maker"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더에 있는 `Translator.java` 파일을 엽니다.

1. `Translator.java` 파일의 전체 내용을 다음 코드로 바꿉니다.  
**Example Translator.java**  

   ```
   package com.mycompany.testing.mytesthook;
   
   
   import software.amazon.awssdk.services.s3.model.GetBucketEncryptionRequest;
   import software.amazon.awssdk.services.s3.model.ListBucketsRequest;
   import software.amazon.awssdk.services.sqs.model.ListQueuesRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   /**
    * This class is a centralized placeholder for
    *  - api request construction
    *  - object translation to/from aws sdk
    */
   
   public class Translator {
   
       static ListBucketsRequest translateToListBucketsRequest(final HookTargetModel targetModel) {
           return ListBucketsRequest.builder().build();
       }
   
       static ListQueuesRequest translateToListQueuesRequest(final String nextToken) {
           return ListQueuesRequest.builder().nextToken(nextToken).build();
       }
   
       static ListBucketsRequest createListBucketsRequest() {
           return ListBucketsRequest.builder().build();
       }
   
       static ListQueuesRequest createListQueuesRequest() {
           return createListQueuesRequest(null);
       }
   
       static ListQueuesRequest createListQueuesRequest(final String nextToken) {
           return ListQueuesRequest.builder().nextToken(nextToken).build();
       }
   
       static GetBucketEncryptionRequest createGetBucketEncryptionRequest(final String bucket) {
           return GetBucketEncryptionRequest.builder().bucket(bucket).build();
       }
   }
   ```

### 헬퍼 코드 구현
<a name="implement-helper-code"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더에 있는 `AbstractTestBase.java` 파일을 엽니다.

1. `AbstractTestBase.java` 파일의 전체 내용을 다음 코드로 바꿉니다.  
**Example Translator.java**  

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.google.common.collect.ImmutableMap;
   import org.mockito.Mockito;
   import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider;
   import software.amazon.awssdk.auth.credentials.AwsSessionCredentials;
   import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
   import software.amazon.awssdk.awscore.AwsRequest;
   import software.amazon.awssdk.awscore.AwsRequestOverrideConfiguration;
   import software.amazon.awssdk.awscore.AwsResponse;
   import software.amazon.awssdk.core.SdkClient;
   import software.amazon.awssdk.core.pagination.sync.SdkIterable;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.Credentials;
   import software.amazon.cloudformation.proxy.LoggerProxy;
   import software.amazon.cloudformation.proxy.OperationStatus;
   import software.amazon.cloudformation.proxy.ProgressEvent;
   import software.amazon.cloudformation.proxy.ProxyClient;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   import javax.annotation.Nonnull;
   import java.time.Duration;
   import java.util.concurrent.CompletableFuture;
   import java.util.function.Function;
   import java.util.function.Supplier;
   
   import static org.assertj.core.api.Assertions.assertThat;
   
   @lombok.Getter
   public class AbstractTestBase {
       protected final AwsSessionCredentials awsSessionCredential;
       protected final AwsCredentialsProvider v2CredentialsProvider;
       protected final AwsRequestOverrideConfiguration configuration;
       protected final LoggerProxy loggerProxy;
       protected final Supplier<Long> awsLambdaRuntime = () -> Duration.ofMinutes(15).toMillis();
       protected final AmazonWebServicesClientProxy proxy;
       protected final Credentials mockCredentials =
           new Credentials("mockAccessId", "mockSecretKey", "mockSessionToken");
   
       @lombok.Setter
       private SdkClient serviceClient;
   
       protected AbstractTestBase() {
           loggerProxy = Mockito.mock(LoggerProxy.class);
           awsSessionCredential = AwsSessionCredentials.create(mockCredentials.getAccessKeyId(),
               mockCredentials.getSecretAccessKey(), mockCredentials.getSessionToken());
           v2CredentialsProvider = StaticCredentialsProvider.create(awsSessionCredential);
           configuration = AwsRequestOverrideConfiguration.builder()
               .credentialsProvider(v2CredentialsProvider)
               .build();
           proxy = new AmazonWebServicesClientProxy(
               loggerProxy,
               mockCredentials,
               awsLambdaRuntime
           ) {
               @Override
               public <ClientT> ProxyClient<ClientT> newProxy(@Nonnull Supplier<ClientT> client) {
                   return new ProxyClient<ClientT>() {
                       @Override
                       public <RequestT extends AwsRequest, ResponseT extends AwsResponse>
                           ResponseT injectCredentialsAndInvokeV2(RequestT request,
                                                                  Function<RequestT, ResponseT> requestFunction) {
                           return proxy.injectCredentialsAndInvokeV2(request, requestFunction);
                       }
   
                       @Override
                       public <RequestT extends AwsRequest, ResponseT extends AwsResponse> CompletableFuture<ResponseT>
                           injectCredentialsAndInvokeV2Async(RequestT request, Function<RequestT, CompletableFuture<ResponseT>> requestFunction) {
                           return proxy.injectCredentialsAndInvokeV2Async(request, requestFunction);
                       }
   
                       @Override
                       public <RequestT extends AwsRequest, ResponseT extends AwsResponse, IterableT extends SdkIterable<ResponseT>>
                           IterableT
                           injectCredentialsAndInvokeIterableV2(RequestT request, Function<RequestT, IterableT> requestFunction) {
                           return proxy.injectCredentialsAndInvokeIterableV2(request, requestFunction);
                       }
   
                       @SuppressWarnings("unchecked")
                       @Override
                       public ClientT client() {
                           return (ClientT) serviceClient;
                       }
                   };
               }
           };
       }
   
       protected void assertResponse(final ProgressEvent<HookTargetModel, CallbackContext> response, final OperationStatus expectedStatus, final String expectedMsg) {
           assertThat(response).isNotNull();
           assertThat(response.getStatus()).isEqualTo(expectedStatus);
           assertThat(response.getCallbackContext()).isNull();
           assertThat(response.getCallbackDelaySeconds()).isEqualTo(0);
           assertThat(response.getMessage()).isNotNull();
           assertThat(response.getMessage()).isEqualTo(expectedMsg);
       }
   
       protected HookTargetModel createHookTargetModel(final Object resourceProperties) {
           return HookTargetModel.of(ImmutableMap.of("ResourceProperties", resourceProperties));
       }
       
       protected HookTargetModel createHookTargetModel(final Object resourceProperties, final Object previousResourceProperties) {
           return HookTargetModel.of(
                   ImmutableMap.of(
                       "ResourceProperties", resourceProperties,
                       "PreviousResourceProperties", previousResourceProperties
                   )
           );
       }
   }
   ```

### 기본 핸들러 구현
<a name="implement-base-hook-handler"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더에 있는 `BaseHookHandlerStd.java` 파일을 엽니다.

1. `BaseHookHandlerStd.java` 파일의 전체 내용을 다음 코드로 바꿉니다.  
**Example Translator.java**  

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueue;
   import software.amazon.awssdk.services.s3.S3Client;
   import software.amazon.awssdk.services.sqs.SqsClient;
   import software.amazon.cloudformation.exceptions.UnsupportedTargetException;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.ProgressEvent;
   import software.amazon.cloudformation.proxy.ProxyClient;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   
   public abstract class BaseHookHandlerStd extends BaseHookHandler<CallbackContext, TypeConfigurationModel> {
       public static final String HOOK_TYPE_NAME = "MyCompany::Testing::MyTestHook";
   
       protected Logger logger;
   
       @Override
       public ProgressEvent<HookTargetModel, CallbackContext> handleRequest(
               final AmazonWebServicesClientProxy proxy,
               final HookHandlerRequest request,
               final CallbackContext callbackContext,
               final Logger logger,
               final TypeConfigurationModel typeConfiguration
       ) {
           this.logger = logger;
   
           final String targetName = request.getHookContext().getTargetName();
   
           final ProgressEvent<HookTargetModel, CallbackContext> result;
           if (AwsS3Bucket.TYPE_NAME.equals(targetName)) {
               result = handleS3BucketRequest(
                       proxy,
                       request,
                       callbackContext != null ? callbackContext : new CallbackContext(),
                       proxy.newProxy(ClientBuilder::createS3Client),
                       typeConfiguration
               );
           } else if (AwsSqsQueue.TYPE_NAME.equals(targetName)) {
               result = handleSqsQueueRequest(
                       proxy,
                       request,
                       callbackContext != null ? callbackContext : new CallbackContext(),
                       proxy.newProxy(ClientBuilder::createSqsClient),
                       typeConfiguration
               );
           } else {
               throw new UnsupportedTargetException(targetName);
           }
   
           log(
               String.format(
                   "Result for [%s] invocation for target [%s] returned status [%s] with message [%s]",
                   request.getHookContext().getInvocationPoint(),
                   targetName,
                   result.getStatus(),
                   result.getMessage()
               )
           );
   
           return result;
       }
   
       protected abstract ProgressEvent<HookTargetModel, CallbackContext> handleS3BucketRequest(
               final AmazonWebServicesClientProxy proxy,
               final HookHandlerRequest request,
               final CallbackContext callbackContext,
               final ProxyClient<S3Client> proxyClient,
               final TypeConfigurationModel typeConfiguration
       );
   
       protected abstract ProgressEvent<HookTargetModel, CallbackContext> handleSqsQueueRequest(
               final AmazonWebServicesClientProxy proxy,
               final HookHandlerRequest request,
               final CallbackContext callbackContext,
               final ProxyClient<SqsClient> proxyClient,
               final TypeConfigurationModel typeConfiguration
       );
   
       protected void log(final String message) {
           if (logger != null) {
               logger.log(message);
           } else {
               System.out.println(message);
           }
       }
   }
   ```

### `preCreate` 핸들러 구현
<a name="implementing-precreate-handler"></a>

`preCreate` 핸들러는 `AWS::S3::Bucket` 또는 `AWS::SQS::Queue` 리소스에 대한 서버 측 암호화 설정을 확인합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  + Amazon S3 버킷 암호화가 설정되어 있습니다.
  + 버킷에 대해 Amazon S3 버킷 키가 활성화됩니다.
  + Amazon S3 버킷에 설정된 암호화 알고리즘이 필요한 올바른 알고리즘입니다.
  +  AWS Key Management Service 키 ID가 설정됩니다.
+ `AWS::SQS::Queue` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  +  AWS Key Management Service 키 ID가 설정됩니다.

### `preCreate` 핸들러 코딩
<a name="coding-the-precreate-handler"></a>

1. IDE에서 `src/main/java/software/mycompany/testing/mytesthook` 폴더에 있는 `PreCreateHookHandler.java` 파일을 엽니다.

1. `PreCreateHookHandler.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3BucketTargetModel;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.BucketEncryption;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionByDefault;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionRule;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueue;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueueTargetModel;
   import org.apache.commons.collections.CollectionUtils;
   import org.apache.commons.lang3.StringUtils;
   import software.amazon.cloudformation.exceptions.UnsupportedTargetException;
   import software.amazon.cloudformation.proxy.HandlerErrorCode;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.hook.HookStatus;
   import software.amazon.cloudformation.proxy.hook.HookProgressEvent;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.ResourceHookTargetModel;
   
   import java.util.List;
   
   public class PreCreateHookHandler extends BaseHookHandler<TypeConfigurationModel, CallbackContext> {
   
       @Override
       public HookProgressEvent<CallbackContext> handleRequest(
           final AmazonWebServicesClientProxy proxy,
           final HookHandlerRequest request,
           final CallbackContext callbackContext,
           final Logger logger,
           final TypeConfigurationModel typeConfiguration) {
   
           final String targetName = request.getHookContext().getTargetName();
           if ("AWS::S3::Bucket".equals(targetName)) {
               final ResourceHookTargetModel<AwsS3Bucket> targetModel = request.getHookContext().getTargetModel(AwsS3BucketTargetModel.class);
   
               final AwsS3Bucket bucket = targetModel.getResourceProperties();
               final String encryptionAlgorithm = typeConfiguration.getEncryptionAlgorithm();
   
               return validateS3BucketEncryption(bucket, encryptionAlgorithm);
   
           } else if ("AWS::SQS::Queue".equals(targetName)) {
               final ResourceHookTargetModel<AwsSqsQueue> targetModel = request.getHookContext().getTargetModel(AwsSqsQueueTargetModel.class);
   
               final AwsSqsQueue queue = targetModel.getResourceProperties();
               return validateSQSQueueEncryption(queue);
           } else {
               throw new UnsupportedTargetException(targetName);
           }
       }
   
       private HookProgressEvent<CallbackContext> validateS3BucketEncryption(final AwsS3Bucket bucket, final String requiredEncryptionAlgorithm) {
           HookStatus resultStatus = null;
           String resultMessage = null;
   
           if (bucket != null) {
               final BucketEncryption bucketEncryption = bucket.getBucketEncryption();
               if (bucketEncryption != null) {
                   final List<ServerSideEncryptionRule> serverSideEncryptionRules = bucketEncryption.getServerSideEncryptionConfiguration();
                   if (CollectionUtils.isNotEmpty(serverSideEncryptionRules)) {
                       for (final ServerSideEncryptionRule rule : serverSideEncryptionRules) {
                           final Boolean bucketKeyEnabled = rule.getBucketKeyEnabled();
                           if (bucketKeyEnabled) {
                               final ServerSideEncryptionByDefault serverSideEncryptionByDefault = rule.getServerSideEncryptionByDefault();
   
                               final String encryptionAlgorithm = serverSideEncryptionByDefault.getSSEAlgorithm();
                               final String kmsKeyId = serverSideEncryptionByDefault.getKMSMasterKeyID(); // "KMSMasterKeyID" is name of the property for an AWS::S3::Bucket;
   
                               if (!StringUtils.equals(encryptionAlgorithm, requiredEncryptionAlgorithm) && StringUtils.isBlank(kmsKeyId)) {
                                   resultStatus = HookStatus.FAILED;
                                   resultMessage = "KMS Key ID not set and SSE Encryption Algorithm is incorrect for bucket with name: " + bucket.getBucketName();
                               } else if (!StringUtils.equals(encryptionAlgorithm, requiredEncryptionAlgorithm)) {
                                   resultStatus = HookStatus.FAILED;
                                   resultMessage = "SSE Encryption Algorithm is incorrect for bucket with name: " + bucket.getBucketName();
                               } else if (StringUtils.isBlank(kmsKeyId)) {
                                   resultStatus = HookStatus.FAILED;
                                   resultMessage = "KMS Key ID not set for bucket with name: " + bucket.getBucketName();
                               } else {
                                   resultStatus = HookStatus.SUCCESS;
                                   resultMessage = "Successfully invoked PreCreateHookHandler for target: AWS::S3::Bucket";
                               }
                           } else {
                               resultStatus = HookStatus.FAILED;
                               resultMessage = "Bucket key not enabled for bucket with name: " + bucket.getBucketName();
                           }
   
                           if (resultStatus == HookStatus.FAILED) {
                               break;
                           }
                       }
                   } else {
                       resultStatus = HookStatus.FAILED;
                       resultMessage = "No SSE Encryption configurations for bucket with name: " + bucket.getBucketName();
                   }
               } else {
                   resultStatus = HookStatus.FAILED;
                   resultMessage = "Bucket Encryption not enabled for bucket with name: " + bucket.getBucketName();
               }
           } else {
               resultStatus = HookStatus.FAILED;
               resultMessage = "Resource properties for S3 Bucket target model are empty";
           }
   
           return HookProgressEvent.<CallbackContext>builder()
                   .status(resultStatus)
                   .message(resultMessage)
                   .errorCode(resultStatus == HookStatus.FAILED ? HandlerErrorCode.ResourceConflict : null)
                   .build();
       }
   
       private HookProgressEvent<CallbackContext> validateSQSQueueEncryption(final AwsSqsQueue queue) {
           if (queue == null) {
               return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.FAILED)
                       .message("Resource properties for SQS Queue target model are empty")
                       .errorCode(HandlerErrorCode.ResourceConflict)
                       .build();
           }
   
           final String kmsKeyId = queue.getKmsMasterKeyId(); // "KmsMasterKeyId" is name of the property for an AWS::SQS::Queue
           if (StringUtils.isBlank(kmsKeyId)) {
               return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.FAILED)
                       .message("Server side encryption turned off for queue with name: " + queue.getQueueName())
                       .errorCode(HandlerErrorCode.ResourceConflict)
                       .build();
           }
   
           return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.SUCCESS)
                       .message("Successfully invoked PreCreateHookHandler for target: AWS::SQS::Queue")
                       .build();
       }
   }
   ```

### `preCreate` 테스트 업데이트
<a name="updating-the-precreate-handler"></a>

1. IDE에서 `src/test/java/software/mycompany/testing/mytesthook` 폴더에 있는 `PreCreateHandlerTest.java` 파일을 엽니다.

1. `PreCreateHandlerTest.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.google.common.collect.ImmutableMap;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.BucketEncryption;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionByDefault;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionRule;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueue;
   import org.junit.jupiter.api.BeforeEach;
   import org.junit.jupiter.api.Test;
   import org.junit.jupiter.api.extension.ExtendWith;
   import org.mockito.Mock;
   import org.mockito.junit.jupiter.MockitoExtension;
   import software.amazon.cloudformation.exceptions.UnsupportedTargetException;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.HandlerErrorCode;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.hook.HookContext;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.HookProgressEvent;
   import software.amazon.cloudformation.proxy.hook.HookStatus;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   import java.util.Collections;
   import java.util.Map;
   
   import static org.assertj.core.api.Assertions.assertThat;
   import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
   import static org.mockito.Mockito.mock;
   
   @ExtendWith(MockitoExtension.class)
   public class PreCreateHookHandlerTest {
   
       @Mock
       private AmazonWebServicesClientProxy proxy;
   
       @Mock
       private Logger logger;
   
       @BeforeEach
       public void setup() {
           proxy = mock(AmazonWebServicesClientProxy.class);
           logger = mock(Logger.class);
       }
       
       @Test
       public void handleRequest_awsSqsQueueSuccess() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsSqsQueue queue = buildSqsQueue("MyQueue", "KmsKey");
           final HookTargetModel targetModel = createHookTargetModel(queue);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::SQS::Queue").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.SUCCESS, "Successfully invoked PreCreateHookHandler for target: AWS::SQS::Queue");
       }
   
       @Test
       public void handleRequest_awsS3BucketSuccess() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsS3Bucket bucket = buildAwsS3Bucket("amzn-s3-demo-bucket", true, "AES256", "KmsKey");
           final HookTargetModel targetModel = createHookTargetModel(bucket);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.SUCCESS, "Successfully invoked PreCreateHookHandler for target: AWS::S3::Bucket");
       }
   
       @Test
       public void handleRequest_awsS3BucketFail_bucketKeyNotEnabled() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsS3Bucket bucket = buildAwsS3Bucket("amzn-s3-demo-bucket", false, "AES256", "KmsKey");
           final HookTargetModel targetModel = createHookTargetModel(bucket);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, "Bucket key not enabled for bucket with name: amzn-s3-demo-bucket");
       }
   
       @Test
       public void handleRequest_awsS3BucketFail_incorrectSSEEncryptionAlgorithm() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsS3Bucket bucket = buildAwsS3Bucket("amzn-s3-demo-bucket", true, "SHA512", "KmsKey");
           final HookTargetModel targetModel = createHookTargetModel(bucket);
          final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, "SSE Encryption Algorithm is incorrect for bucket with name: amzn-s3-demo-bucket");
       }
   
       @Test
       public void handleRequest_awsS3BucketFail_kmsKeyIdNotSet() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsS3Bucket bucket = buildAwsS3Bucket("amzn-s3-demo-bucket", true, "AES256", null);
           final HookTargetModel targetModel = createHookTargetModel(bucket);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, "KMS Key ID not set for bucket with name: amzn-s3-demo-bucket");
       }
   
       @Test
       public void handleRequest_awsSqsQueueFail_serverSideEncryptionOff() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final AwsSqsQueue queue = buildSqsQueue("MyQueue", null);
           final HookTargetModel targetModel = createHookTargetModel(queue);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::SQS::Queue").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, "Server side encryption turned off for queue with name: MyQueue");
       }
   
       @Test
       public void handleRequest_unsupportedTarget() {
           final PreCreateHookHandler handler = new PreCreateHookHandler();
   
           final Map<String, Object> unsupportedTarget = ImmutableMap.of("ResourceName", "MyUnsupportedTarget");
           final HookTargetModel targetModel = createHookTargetModel(unsupportedTarget);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::Unsupported::Target").targetModel(targetModel).build())
               .build();
   
           assertThatExceptionOfType(UnsupportedTargetException.class)
                   .isThrownBy(() -> handler.handleRequest(proxy, request, null, logger, typeConfiguration))
                   .withMessageContaining("Unsupported target")
                   .withMessageContaining("AWS::Unsupported::Target")
                   .satisfies(e -> assertThat(e.getErrorCode()).isEqualTo(HandlerErrorCode.InvalidRequest));
       }
   
       private void assertResponse(final HookProgressEvent<CallbackContext> response, final HookStatus expectedStatus, final String expectedErrorMsg) {
           assertThat(response).isNotNull();
           assertThat(response.getStatus()).isEqualTo(expectedStatus);
           assertThat(response.getCallbackContext()).isNull();
           assertThat(response.getCallbackDelaySeconds()).isEqualTo(0);
           assertThat(response.getMessage()).isNotNull();
           assertThat(response.getMessage()).isEqualTo(expectedErrorMsg);
       }
   
       private HookTargetModel createHookTargetModel(final Object resourceProperties) {
           return HookTargetModel.of(ImmutableMap.of("ResourceProperties", resourceProperties));
       }
   
       @SuppressWarnings("SameParameterValue")
       private AwsSqsQueue buildSqsQueue(final String queueName, final String kmsKeyId) {
           return AwsSqsQueue.builder()
                   .queueName(queueName)
                   .kmsMasterKeyId(kmsKeyId) // "KmsMasterKeyId" is name of the property for an AWS::SQS::Queue
                   .build();
       }
   
       @SuppressWarnings("SameParameterValue")
       private AwsS3Bucket buildAwsS3Bucket(
               final String bucketName,
               final Boolean bucketKeyEnabled,
               final String sseAlgorithm,
               final String kmsKeyId
       ) {
           return AwsS3Bucket.builder()
                   .bucketName(bucketName)
                   .bucketEncryption(
                       BucketEncryption.builder()
                           .serverSideEncryptionConfiguration(
                               Collections.singletonList(
                                   ServerSideEncryptionRule.builder()
                                       .bucketKeyEnabled(bucketKeyEnabled)
                                       .serverSideEncryptionByDefault(
                                           ServerSideEncryptionByDefault.builder()
                                               .sSEAlgorithm(sseAlgorithm)
                                               .kMSMasterKeyID(kmsKeyId) // "KMSMasterKeyID" is name of the property for an AWS::S3::Bucket
                                               .build()
                                       ).build()
                               )
                           ).build()
                   ).build();
       }
   }
   ```

### `preUpdate` 핸들러 구현
<a name="implementing-preupdate-handler"></a>

`preUpdate` 핸들러에서 지정된 모든 대상에 대한 업데이트 작업 전에 시작하는 핸들러를 구현합니다. `preUpdate` 핸들러는 다음을 수행합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  + Amazon S3 버킷의 버킷 암호화 알고리즘이 수정되지 않았습니다.

### `preUpdate` 핸들러 코딩
<a name="coding-preupdate-handler"></a>

1. IDE에서 `src/main/java/software/mycompany/testing/mytesthook` 폴더에 있는 `PreUpdateHookHandler.java` 파일을 엽니다.

1. `PreUpdateHookHandler.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3BucketTargetModel;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionRule;
   import org.apache.commons.lang3.StringUtils;
   import software.amazon.cloudformation.exceptions.UnsupportedTargetException;
   import software.amazon.cloudformation.proxy.HandlerErrorCode;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.hook.HookStatus;
   import software.amazon.cloudformation.proxy.hook.HookProgressEvent;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.ResourceHookTargetModel;
   
   import java.util.List;
   
   public class PreUpdateHookHandler extends BaseHookHandler<TypeConfigurationModel, CallbackContext> {
   
       @Override
       public HookProgressEvent<CallbackContext> handleRequest(
           final AmazonWebServicesClientProxy proxy,
           final HookHandlerRequest request,
           final CallbackContext callbackContext,
           final Logger logger,
           final TypeConfigurationModel typeConfiguration) {
   
           final String targetName = request.getHookContext().getTargetName();
           if ("AWS::S3::Bucket".equals(targetName)) {
               final ResourceHookTargetModel<AwsS3Bucket> targetModel = request.getHookContext().getTargetModel(AwsS3BucketTargetModel.class);
   
               final AwsS3Bucket bucketProperties = targetModel.getResourceProperties();
               final AwsS3Bucket previousBucketProperties = targetModel.getPreviousResourceProperties();
   
               return validateBucketEncryptionRulesNotUpdated(bucketProperties, previousBucketProperties);
           } else {
               throw new UnsupportedTargetException(targetName);
           }
       }
   
       private HookProgressEvent<CallbackContext> validateBucketEncryptionRulesNotUpdated(final AwsS3Bucket resourceProperties, final AwsS3Bucket previousResourceProperties) {
           final List<ServerSideEncryptionRule> bucketEncryptionConfigs = resourceProperties.getBucketEncryption().getServerSideEncryptionConfiguration();
           final List<ServerSideEncryptionRule> previousBucketEncryptionConfigs = previousResourceProperties.getBucketEncryption().getServerSideEncryptionConfiguration();
   
           if (bucketEncryptionConfigs.size() != previousBucketEncryptionConfigs.size()) {
               return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.FAILED)
                       .errorCode(HandlerErrorCode.NotUpdatable)
                       .message(
                           String.format(
                               "Current number of bucket encryption configs does not match previous. Current has %d configs while previously there were %d configs",
                               bucketEncryptionConfigs.size(),
                               previousBucketEncryptionConfigs.size()
                           )
                       ).build();
           }
   
           for (int i = 0; i < bucketEncryptionConfigs.size(); ++i) {
               final String currentEncryptionAlgorithm = bucketEncryptionConfigs.get(i).getServerSideEncryptionByDefault().getSSEAlgorithm();
               final String previousEncryptionAlgorithm = previousBucketEncryptionConfigs.get(i).getServerSideEncryptionByDefault().getSSEAlgorithm();
   
               if (!StringUtils.equals(currentEncryptionAlgorithm, previousEncryptionAlgorithm)) {
                   return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.FAILED)
                       .errorCode(HandlerErrorCode.NotUpdatable)
                       .message(
                           String.format(
                               "Bucket Encryption algorithm can not be changed once set. The encryption algorithm was changed to '%s' from '%s'.",
                               currentEncryptionAlgorithm,
                               previousEncryptionAlgorithm
                           )
                       )
                       .build();
               }
           }
   
           return HookProgressEvent.<CallbackContext>builder()
                       .status(HookStatus.SUCCESS)
                       .message("Successfully invoked PreUpdateHookHandler for target: AWS::SQS::Queue")
                       .build();
       }
   }
   ```

### `preUpdate` 테스트 업데이트
<a name="update-the-preupdate-handler"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더의 `PreUpdateHandlerTest.java` 파일을 엽니다.

1. `PreUpdateHandlerTest.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.google.common.collect.ImmutableMap;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.BucketEncryption;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionByDefault;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.ServerSideEncryptionRule;
   import org.junit.jupiter.api.BeforeEach;
   import org.junit.jupiter.api.Test;
   import org.junit.jupiter.api.extension.ExtendWith;
   import org.mockito.Mock;
   import org.mockito.junit.jupiter.MockitoExtension;
   import software.amazon.cloudformation.exceptions.UnsupportedTargetException;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.HandlerErrorCode;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.hook.HookContext;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.HookProgressEvent;
   import software.amazon.cloudformation.proxy.hook.HookStatus;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   import java.util.Arrays;
   import java.util.stream.Stream;
   
   import static org.assertj.core.api.Assertions.assertThat;
   import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
   import static org.mockito.Mockito.mock;
   
   @ExtendWith(MockitoExtension.class)
   public class PreUpdateHookHandlerTest {
   
       @Mock
       private AmazonWebServicesClientProxy proxy;
   
       @Mock
       private Logger logger;
   
       @BeforeEach
       public void setup() {
           proxy = mock(AmazonWebServicesClientProxy.class);
           logger = mock(Logger.class);
       }
   
       @Test
       public void handleRequest_awsS3BucketSuccess() {
           final PreUpdateHookHandler handler = new PreUpdateHookHandler();
   
           final ServerSideEncryptionRule serverSideEncryptionRule = buildServerSideEncryptionRule("AES256");
           final AwsS3Bucket resourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", serverSideEncryptionRule);
           final AwsS3Bucket previousResourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", serverSideEncryptionRule);
           final HookTargetModel targetModel = createHookTargetModel(resourceProperties, previousResourceProperties);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.SUCCESS, "Successfully invoked PreUpdateHookHandler for target: AWS::SQS::Queue");
       }
   
       @Test
       public void handleRequest_awsS3BucketFail_bucketEncryptionConfigsDontMatch() {
           final PreUpdateHookHandler handler = new PreUpdateHookHandler();
   
           final ServerSideEncryptionRule[] serverSideEncryptionRules = Stream.of("AES256", "SHA512", "AES32")
                   .map(this::buildServerSideEncryptionRule)
                   .toArray(ServerSideEncryptionRule[]::new);
   
           final AwsS3Bucket resourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", serverSideEncryptionRules[0]);
           final AwsS3Bucket previousResourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", serverSideEncryptionRules);
           final HookTargetModel targetModel = createHookTargetModel(resourceProperties, previousResourceProperties);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, "Current number of bucket encryption configs does not match previous. Current has 1 configs while previously there were 3 configs");
       }
   
       @Test
       public void handleRequest_awsS3BucketFail_bucketEncryptionAlgorithmDoesNotMatch() {
           final PreUpdateHookHandler handler = new PreUpdateHookHandler();
   
           final AwsS3Bucket resourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", buildServerSideEncryptionRule("SHA512"));
           final AwsS3Bucket previousResourceProperties = buildAwsS3Bucket("amzn-s3-demo-bucket", buildServerSideEncryptionRule("AES256"));
           final HookTargetModel targetModel = createHookTargetModel(resourceProperties, previousResourceProperties);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::S3::Bucket").targetModel(targetModel).build())
               .build();
   
           final HookProgressEvent<CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
           assertResponse(response, HookStatus.FAILED, String.format("Bucket Encryption algorithm can not be changed once set. The encryption algorithm was changed to '%s' from '%s'.", "SHA512", "AES256"));
       }
   
       @Test
       public void handleRequest_unsupportedTarget() {
           final PreUpdateHookHandler handler = new PreUpdateHookHandler();
   
           final Object resourceProperties = ImmutableMap.of("FileSizeLimit", 256);
           final Object previousResourceProperties = ImmutableMap.of("FileSizeLimit", 512);
           final HookTargetModel targetModel = createHookTargetModel(resourceProperties, previousResourceProperties);
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder().encryptionAlgorithm("AES256").build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
               .hookContext(HookContext.builder().targetName("AWS::Unsupported::Target").targetModel(targetModel).build())
               .build();
   
           assertThatExceptionOfType(UnsupportedTargetException.class)
                   .isThrownBy(() -> handler.handleRequest(proxy, request, null, logger, typeConfiguration))
                   .withMessageContaining("Unsupported target")
                   .withMessageContaining("AWS::Unsupported::Target")
                   .satisfies(e -> assertThat(e.getErrorCode()).isEqualTo(HandlerErrorCode.InvalidRequest));
       }
   
       private void assertResponse(final HookProgressEvent<CallbackContext> response, final HookStatus expectedStatus, final String expectedErrorMsg) {
           assertThat(response).isNotNull();
           assertThat(response.getStatus()).isEqualTo(expectedStatus);
           assertThat(response.getCallbackContext()).isNull();
           assertThat(response.getCallbackDelaySeconds()).isEqualTo(0);
           assertThat(response.getMessage()).isNotNull();
           assertThat(response.getMessage()).isEqualTo(expectedErrorMsg);
       }
   
       private HookTargetModel createHookTargetModel(final Object resourceProperties, final Object previousResourceProperties) {
           return HookTargetModel.of(
                   ImmutableMap.of(
                       "ResourceProperties", resourceProperties,
                       "PreviousResourceProperties", previousResourceProperties
                   )
           );
       }
   
       @SuppressWarnings("SameParameterValue")
       private AwsS3Bucket buildAwsS3Bucket(
               final String bucketName,
               final ServerSideEncryptionRule ...serverSideEncryptionRules
               ) {
           return AwsS3Bucket.builder()
                   .bucketName(bucketName)
                   .bucketEncryption(
                       BucketEncryption.builder()
                           .serverSideEncryptionConfiguration(
                                   Arrays.asList(serverSideEncryptionRules)
                           ).build()
                   ).build();
       }
   
       private ServerSideEncryptionRule buildServerSideEncryptionRule(final String encryptionAlgorithm) {
           return ServerSideEncryptionRule.builder()
                   .bucketKeyEnabled(true)
                   .serverSideEncryptionByDefault(
                           ServerSideEncryptionByDefault.builder()
                                   .sSEAlgorithm(encryptionAlgorithm)
                                   .build()
                   ).build();
       }
   }
   ```

### `preDelete` 핸들러 구현
<a name="implement-the-predelete-hander"></a>

`preDelete` 핸들러에서 지정된 모든 대상에 대한 삭제 작업 전에 시작하는 핸들러를 구현합니다. `preDelete` 핸들러는 다음을 수행합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  + 리소스를 삭제한 후 계정에 필요한 최소 수신 거부 리소스가 있는지 확인합니다.
  + 최소 필수 수신 거부 리소스 양은 후크의 유형 구성에서 설정됩니다.

### `preDelete` 핸들러 코딩
<a name="code-the-predelete-handler"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더의 `PreDeleteHookHandler.java` 파일을 엽니다.

1. `PreDeleteHookHandler.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.google.common.annotations.VisibleForTesting;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3BucketTargetModel;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueue;
   import com.mycompany.testing.mytesthook.model.aws.sqs.queue.AwsSqsQueueTargetModel;
   import org.apache.commons.lang3.StringUtils;
   import org.apache.commons.lang3.math.NumberUtils;
   import software.amazon.awssdk.services.cloudformation.CloudFormationClient;
   import software.amazon.awssdk.services.cloudformation.model.CloudFormationException;
   import software.amazon.awssdk.services.cloudformation.model.DescribeStackResourceRequest;
   import software.amazon.awssdk.services.s3.S3Client;
   import software.amazon.awssdk.services.s3.model.Bucket;
   import software.amazon.awssdk.services.s3.model.S3Exception;
   import software.amazon.awssdk.services.sqs.SqsClient;
   import software.amazon.awssdk.services.sqs.model.GetQueueAttributesRequest;
   import software.amazon.awssdk.services.sqs.model.GetQueueUrlRequest;
   import software.amazon.awssdk.services.sqs.model.ListQueuesRequest;
   import software.amazon.awssdk.services.sqs.model.ListQueuesResponse;
   import software.amazon.awssdk.services.sqs.model.QueueAttributeName;
   import software.amazon.awssdk.services.sqs.model.SqsException;
   import software.amazon.cloudformation.exceptions.CfnGeneralServiceException;
   import software.amazon.cloudformation.proxy.AmazonWebServicesClientProxy;
   import software.amazon.cloudformation.proxy.HandlerErrorCode;
   import software.amazon.cloudformation.proxy.OperationStatus;
   import software.amazon.cloudformation.proxy.ProgressEvent;
   import software.amazon.cloudformation.proxy.ProxyClient;
   import software.amazon.cloudformation.proxy.hook.HookContext;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   import software.amazon.cloudformation.proxy.hook.targetmodel.ResourceHookTargetModel;
   
   import java.util.ArrayList;
   import java.util.Collection;
   import java.util.HashSet;
   import java.util.List;
   import java.util.Objects;
   import java.util.stream.Collectors;
   
   public class PreDeleteHookHandler extends BaseHookHandlerStd {
   
       private ProxyClient<S3Client> s3Client;
       private ProxyClient<SqsClient> sqsClient;
   
       @Override
       protected ProgressEvent<HookTargetModel, CallbackContext> handleS3BucketRequest(
               final AmazonWebServicesClientProxy proxy,
               final HookHandlerRequest request,
               final CallbackContext callbackContext,
               final ProxyClient<S3Client> proxyClient,
               final TypeConfigurationModel typeConfiguration
       ) {
           final HookContext hookContext = request.getHookContext();
           final String targetName = hookContext.getTargetName();
           if (!AwsS3Bucket.TYPE_NAME.equals(targetName)) {
               throw new RuntimeException(String.format("Request target type [%s] is not 'AWS::S3::Bucket'", targetName));
           }
           this.s3Client = proxyClient;
   
           final String encryptionAlgorithm = typeConfiguration.getEncryptionAlgorithm();
           final int minBuckets = NumberUtils.toInt(typeConfiguration.getMinBuckets());
   
           final ResourceHookTargetModel<AwsS3Bucket> targetModel = hookContext.getTargetModel(AwsS3BucketTargetModel.class);
           final List<String> buckets = listBuckets().stream()
                   .filter(b -> !StringUtils.equals(b, targetModel.getResourceProperties().getBucketName()))
                   .collect(Collectors.toList());
   
           final List<String> compliantBuckets = new ArrayList<>();
           for (final String bucket : buckets) {
               if (getBucketSSEAlgorithm(bucket).contains(encryptionAlgorithm)) {
                   compliantBuckets.add(bucket);
               }
   
               if (compliantBuckets.size() >= minBuckets) {
                   return ProgressEvent.<HookTargetModel, CallbackContext>builder()
                           .status(OperationStatus.SUCCESS)
                           .message("Successfully invoked PreDeleteHookHandler for target: AWS::S3::Bucket")
                           .build();
               }
           }
   
           return ProgressEvent.<HookTargetModel, CallbackContext>builder()
                   .status(OperationStatus.FAILED)
                   .errorCode(HandlerErrorCode.NonCompliant)
                   .message(String.format("Failed to meet minimum of [%d] encrypted buckets.", minBuckets))
                   .build();
       }
   
       @Override
       protected ProgressEvent<HookTargetModel, CallbackContext> handleSqsQueueRequest(
               final AmazonWebServicesClientProxy proxy,
               final HookHandlerRequest request,
               final CallbackContext callbackContext,
               final ProxyClient<SqsClient> proxyClient,
               final TypeConfigurationModel typeConfiguration
       ) {
           final HookContext hookContext = request.getHookContext();
           final String targetName = hookContext.getTargetName();
           if (!AwsSqsQueue.TYPE_NAME.equals(targetName)) {
               throw new RuntimeException(String.format("Request target type [%s] is not 'AWS::SQS::Queue'", targetName));
           }
           this.sqsClient = proxyClient;
           final int minQueues = NumberUtils.toInt(typeConfiguration.getMinQueues());
   
           final ResourceHookTargetModel<AwsSqsQueue> targetModel = hookContext.getTargetModel(AwsSqsQueueTargetModel.class);
   
           final String queueName = Objects.toString(targetModel.getResourceProperties().get("QueueName"), null);
   
           String targetQueueUrl = null;
           if (queueName != null) {
               try {
                   targetQueueUrl = sqsClient.injectCredentialsAndInvokeV2(
                           GetQueueUrlRequest.builder().queueName(
                                   queueName
                           ).build(),
                           sqsClient.client()::getQueueUrl
                   ).queueUrl();
               } catch (SqsException e) {
                   log(String.format("Error while calling GetQueueUrl API for queue name [%s]: %s", queueName, e.getMessage()));
               }
           } else {
               log("Queue name is empty, attempting to get queue's physical ID");
               try {
                   final ProxyClient<CloudFormationClient> cfnClient = proxy.newProxy(ClientBuilder::createCloudFormationClient);
                   targetQueueUrl = cfnClient.injectCredentialsAndInvokeV2(
                           DescribeStackResourceRequest.builder()
                                   .stackName(hookContext.getTargetLogicalId())
                                   .logicalResourceId(hookContext.getTargetLogicalId())
                                   .build(),
                           cfnClient.client()::describeStackResource
                   ).stackResourceDetail().physicalResourceId();
               } catch (CloudFormationException e) {
                   log(String.format("Error while calling DescribeStackResource API for queue name: %s", e.getMessage()));
               }
           }
   
           // Creating final variable for the filter lambda
           final String finalTargetQueueUrl = targetQueueUrl;
   
           final List<String> compliantQueues = new ArrayList<>();
   
           String nextToken = null;
           do {
               final ListQueuesRequest req = Translator.createListQueuesRequest(nextToken);
               final ListQueuesResponse res = sqsClient.injectCredentialsAndInvokeV2(req, sqsClient.client()::listQueues);
               final List<String> queueUrls = res.queueUrls().stream()
                       .filter(q -> !StringUtils.equals(q, finalTargetQueueUrl))
                       .collect(Collectors.toList());
   
               for (final String queueUrl : queueUrls) {
                   if (isQueueEncrypted(queueUrl)) {
                       compliantQueues.add(queueUrl);
                   }
   
                   if (compliantQueues.size() >= minQueues) {
                       return ProgressEvent.<HookTargetModel, CallbackContext>builder()
                           .status(OperationStatus.SUCCESS)
                           .message("Successfully invoked PreDeleteHookHandler for target: AWS::SQS::Queue")
                           .build();
                   }
                   nextToken = res.nextToken();
               }
           } while (nextToken != null);
   
           return ProgressEvent.<HookTargetModel, CallbackContext>builder()
                   .status(OperationStatus.FAILED)
                   .errorCode(HandlerErrorCode.NonCompliant)
                   .message(String.format("Failed to meet minimum of [%d] encrypted queues.", minQueues))
                   .build();
       }
   
       private List<String> listBuckets() {
           try {
               return s3Client.injectCredentialsAndInvokeV2(Translator.createListBucketsRequest(), s3Client.client()::listBuckets)
                       .buckets()
                       .stream()
                       .map(Bucket::name)
                       .collect(Collectors.toList());
           } catch (S3Exception e) {
               throw new CfnGeneralServiceException("Error while calling S3 ListBuckets API", e);
           }
       }
   
       @VisibleForTesting
       Collection<String> getBucketSSEAlgorithm(final String bucket) {
           try {
               return s3Client.injectCredentialsAndInvokeV2(Translator.createGetBucketEncryptionRequest(bucket), s3Client.client()::getBucketEncryption)
                       .serverSideEncryptionConfiguration()
                       .rules()
                       .stream()
                       .filter(r -> Objects.nonNull(r.applyServerSideEncryptionByDefault()))
                       .map(r -> r.applyServerSideEncryptionByDefault().sseAlgorithmAsString())
                       .collect(Collectors.toSet());
           } catch (S3Exception e) {
               return new HashSet<>();
           }
       }
   
       @VisibleForTesting
       boolean isQueueEncrypted(final String queueUrl) {
           try {
               final GetQueueAttributesRequest request = GetQueueAttributesRequest.builder()
                       .queueUrl(queueUrl)
                       .attributeNames(QueueAttributeName.KMS_MASTER_KEY_ID)
                       .build();
               final String kmsKeyId = sqsClient.injectCredentialsAndInvokeV2(request, sqsClient.client()::getQueueAttributes)
                       .attributes()
                       .get(QueueAttributeName.KMS_MASTER_KEY_ID);
   
               return StringUtils.isNotBlank(kmsKeyId);
           } catch (SqsException e) {
               throw new CfnGeneralServiceException("Error while calling SQS GetQueueAttributes API", e);
           }
       }
   }
   ```

### `preDelete` 핸들러 업데이트
<a name="update-the-predelete-handler"></a>

1. IDE에서 `src/main/java/com/mycompany/testing/mytesthook` 폴더의 `PreDeleteHookHandler.java` 파일을 엽니다.

1. `PreDeleteHookHandler.java` 파일의 전체 내용을 다음 코드로 바꿉니다.

   ```
   package com.mycompany.testing.mytesthook;
   
   import com.google.common.collect.ImmutableList;
   import com.google.common.collect.ImmutableMap;
   import com.mycompany.testing.mytesthook.model.aws.s3.bucket.AwsS3Bucket;
   import org.junit.jupiter.api.BeforeEach;
   import org.junit.jupiter.api.Test;
   import org.junit.jupiter.api.extension.ExtendWith;
   import org.mockito.Mock;
   import org.mockito.Mockito;
   import org.mockito.junit.jupiter.MockitoExtension;
   import software.amazon.awssdk.services.s3.S3Client;
   import software.amazon.awssdk.services.s3.model.Bucket;
   import software.amazon.awssdk.services.s3.model.GetBucketEncryptionRequest;
   import software.amazon.awssdk.services.s3.model.GetBucketEncryptionResponse;
   import software.amazon.awssdk.services.s3.model.ListBucketsRequest;
   import software.amazon.awssdk.services.s3.model.ListBucketsResponse;
   import software.amazon.awssdk.services.s3.model.S3Exception;
   import software.amazon.awssdk.services.s3.model.ServerSideEncryptionByDefault;
   import software.amazon.awssdk.services.s3.model.ServerSideEncryptionConfiguration;
   import software.amazon.awssdk.services.s3.model.ServerSideEncryptionRule;
   import software.amazon.awssdk.services.sqs.SqsClient;
   import software.amazon.awssdk.services.sqs.model.GetQueueAttributesRequest;
   import software.amazon.awssdk.services.sqs.model.GetQueueAttributesResponse;
   import software.amazon.awssdk.services.sqs.model.GetQueueUrlRequest;
   import software.amazon.awssdk.services.sqs.model.GetQueueUrlResponse;
   import software.amazon.awssdk.services.sqs.model.ListQueuesRequest;
   import software.amazon.awssdk.services.sqs.model.ListQueuesResponse;
   import software.amazon.awssdk.services.sqs.model.QueueAttributeName;
   import software.amazon.cloudformation.proxy.Logger;
   import software.amazon.cloudformation.proxy.OperationStatus;
   import software.amazon.cloudformation.proxy.ProgressEvent;
   import software.amazon.cloudformation.proxy.hook.HookContext;
   import software.amazon.cloudformation.proxy.hook.HookHandlerRequest;
   import software.amazon.cloudformation.proxy.hook.targetmodel.HookTargetModel;
   
   import java.util.Arrays;
   import java.util.Collection;
   import java.util.HashMap;
   import java.util.List;
   import java.util.stream.Collectors;
   
   import static org.mockito.ArgumentMatchers.any;
   import static org.mockito.Mockito.mock;
   import static org.mockito.Mockito.never;
   import static org.mockito.Mockito.times;
   import static org.mockito.Mockito.verify;
   import static org.mockito.Mockito.when;
   
   @ExtendWith(MockitoExtension.class)
   public class PreDeleteHookHandlerTest extends AbstractTestBase {
   
       @Mock private S3Client s3Client;
       @Mock private SqsClient sqsClient;
       @Mock private Logger logger;
   
       @BeforeEach
       public void setup() {
           s3Client = mock(S3Client.class);
           sqsClient = mock(SqsClient.class);
           logger = mock(Logger.class);
       }
   
       @Test
       public void handleRequest_awsS3BucketSuccess() {
           final PreDeleteHookHandler handler = Mockito.spy(new PreDeleteHookHandler());
   
           final List<Bucket> bucketList = ImmutableList.of(
                   Bucket.builder().name("bucket1").build(),
                   Bucket.builder().name("bucket2").build(),
                   Bucket.builder().name("toBeDeletedBucket").build(),
                   Bucket.builder().name("bucket3").build(),
                   Bucket.builder().name("bucket4").build(),
                   Bucket.builder().name("bucket5").build()
           );
           final ListBucketsResponse mockResponse = ListBucketsResponse.builder().buckets(bucketList).build();
           when(s3Client.listBuckets(any(ListBucketsRequest.class))).thenReturn(mockResponse);
           when(s3Client.getBucketEncryption(any(GetBucketEncryptionRequest.class)))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256"))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256", "aws:kms"))
                   .thenThrow(S3Exception.builder().message("No Encrypt").build())
                   .thenReturn(buildGetBucketEncryptionResponse("aws:kms"))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256"));
           setServiceClient(s3Client);
   
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder()
                   .encryptionAlgorithm("AES256")
                   .minBuckets("3")
                   .build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
                   .hookContext(
                       HookContext.builder()
                           .targetName("AWS::S3::Bucket")
                           .targetModel(
                               createHookTargetModel(
                                   AwsS3Bucket.builder()
                                       .bucketName("toBeDeletedBucket")
                                       .build()
                               )
                           )
                           .build())
                   .build();
   
           final ProgressEvent<HookTargetModel, CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
   
           verify(s3Client, times(5)).getBucketEncryption(any(GetBucketEncryptionRequest.class));
           verify(handler, never()).getBucketSSEAlgorithm("toBeDeletedBucket");
   
           assertResponse(response, OperationStatus.SUCCESS, "Successfully invoked PreDeleteHookHandler for target: AWS::S3::Bucket");
       }
   
   
       @Test
       public void handleRequest_awsSqsQueueSuccess() {
           final PreDeleteHookHandler handler = Mockito.spy(new PreDeleteHookHandler());
   
           final List<String> queueUrls = ImmutableList.of(
                   "https://queue1.queue",
                   "https://queue2.queue",
                   "https://toBeDeletedQueue.queue",
                   "https://queue3.queue",
                   "https://queue4.queue",
                   "https://queue5.queue"
           );
   
           when(sqsClient.getQueueUrl(any(GetQueueUrlRequest.class)))
                   .thenReturn(GetQueueUrlResponse.builder().queueUrl("https://toBeDeletedQueue.queue").build());
           when(sqsClient.listQueues(any(ListQueuesRequest.class)))
                   .thenReturn(ListQueuesResponse.builder().queueUrls(queueUrls).build());
           when(sqsClient.getQueueAttributes(any(GetQueueAttributesRequest.class)))
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(new HashMap<>()).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(new HashMap<>()).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build());
           setServiceClient(sqsClient);
   
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder()
                   .minQueues("3")
                   .build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
                   .hookContext(
                       HookContext.builder()
                           .targetName("AWS::SQS::Queue")
                           .targetModel(
                               createHookTargetModel(
                                   ImmutableMap.of("QueueName", "toBeDeletedQueue")
                               )
                           )
                           .build())
                   .build();
   
           final ProgressEvent<HookTargetModel, CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
   
           verify(sqsClient, times(5)).getQueueAttributes(any(GetQueueAttributesRequest.class));
           verify(handler, never()).isQueueEncrypted("toBeDeletedQueue");
   
           assertResponse(response, OperationStatus.SUCCESS, "Successfully invoked PreDeleteHookHandler for target: AWS::SQS::Queue");
       }
   
       @Test
       public void handleRequest_awsS3BucketFailed() {
           final PreDeleteHookHandler handler = Mockito.spy(new PreDeleteHookHandler());
   
           final List<Bucket> bucketList = ImmutableList.of(
                   Bucket.builder().name("bucket1").build(),
                   Bucket.builder().name("bucket2").build(),
                   Bucket.builder().name("toBeDeletedBucket").build(),
                   Bucket.builder().name("bucket3").build(),
                   Bucket.builder().name("bucket4").build(),
                   Bucket.builder().name("bucket5").build()
           );
           final ListBucketsResponse mockResponse = ListBucketsResponse.builder().buckets(bucketList).build();
           when(s3Client.listBuckets(any(ListBucketsRequest.class))).thenReturn(mockResponse);
           when(s3Client.getBucketEncryption(any(GetBucketEncryptionRequest.class)))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256"))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256", "aws:kms"))
                   .thenThrow(S3Exception.builder().message("No Encrypt").build())
                   .thenReturn(buildGetBucketEncryptionResponse("aws:kms"))
                   .thenReturn(buildGetBucketEncryptionResponse("AES256"));
           setServiceClient(s3Client);
   
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder()
                   .encryptionAlgorithm("AES256")
                   .minBuckets("10")
                   .build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
                   .hookContext(
                       HookContext.builder()
                           .targetName("AWS::S3::Bucket")
                           .targetModel(
                               createHookTargetModel(
                                   AwsS3Bucket.builder()
                                       .bucketName("toBeDeletedBucket")
                                       .build()
                               )
                           )
                           .build())
                   .build();
   
           final ProgressEvent<HookTargetModel, CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
   
           verify(s3Client, times(5)).getBucketEncryption(any(GetBucketEncryptionRequest.class));
           verify(handler, never()).getBucketSSEAlgorithm("toBeDeletedBucket");
   
           assertResponse(response, OperationStatus.FAILED, "Failed to meet minimum of [10] encrypted buckets.");
       }
   
   
       @Test
       public void handleRequest_awsSqsQueueFailed() {
           final PreDeleteHookHandler handler = Mockito.spy(new PreDeleteHookHandler());
   
           final List<String> queueUrls = ImmutableList.of(
                   "https://queue1.queue",
                   "https://queue2.queue",
                   "https://toBeDeletedQueue.queue",
                   "https://queue3.queue",
                   "https://queue4.queue",
                   "https://queue5.queue"
           );
   
           when(sqsClient.getQueueUrl(any(GetQueueUrlRequest.class)))
                   .thenReturn(GetQueueUrlResponse.builder().queueUrl("https://toBeDeletedQueue.queue").build());
           when(sqsClient.listQueues(any(ListQueuesRequest.class)))
                   .thenReturn(ListQueuesResponse.builder().queueUrls(queueUrls).build());
           when(sqsClient.getQueueAttributes(any(GetQueueAttributesRequest.class)))
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(new HashMap<>()).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(new HashMap<>()).build())
                   .thenReturn(GetQueueAttributesResponse.builder().attributes(ImmutableMap.of(QueueAttributeName.KMS_MASTER_KEY_ID, "kmsKeyId")).build());
           setServiceClient(sqsClient);
   
           final TypeConfigurationModel typeConfiguration = TypeConfigurationModel.builder()
                   .minQueues("10")
                   .build();
   
           final HookHandlerRequest request = HookHandlerRequest.builder()
                   .hookContext(
                       HookContext.builder()
                           .targetName("AWS::SQS::Queue")
                           .targetModel(
                               createHookTargetModel(
                                   ImmutableMap.of("QueueName", "toBeDeletedQueue")
                               )
                           )
                           .build())
                   .build();
   
           final ProgressEvent<HookTargetModel, CallbackContext> response = handler.handleRequest(proxy, request, null, logger, typeConfiguration);
   
           verify(sqsClient, times(5)).getQueueAttributes(any(GetQueueAttributesRequest.class));
           verify(handler, never()).isQueueEncrypted("toBeDeletedQueue");
   
           assertResponse(response, OperationStatus.FAILED, "Failed to meet minimum of [10] encrypted queues.");
       }
   
       private GetBucketEncryptionResponse buildGetBucketEncryptionResponse(final String ...sseAlgorithm) {
           return buildGetBucketEncryptionResponse(
                   Arrays.stream(sseAlgorithm)
                       .map(a -> ServerSideEncryptionRule.builder().applyServerSideEncryptionByDefault(
                           ServerSideEncryptionByDefault.builder()
                               .sseAlgorithm(a)
                               .build()
                           ).build()
                       )
                       .collect(Collectors.toList())
           );
       }
   
       private GetBucketEncryptionResponse buildGetBucketEncryptionResponse(final Collection<ServerSideEncryptionRule> rules) {
           return GetBucketEncryptionResponse.builder()
                   .serverSideEncryptionConfiguration(
                       ServerSideEncryptionConfiguration.builder().rules(
                           rules
                       ).build()
                   ).build();
       }
   }
   ```

# Python을 사용하여 사용자 지정 CloudFormation 후크 모델링
<a name="hooks-model-python"></a>

사용자 지정 CloudFormation 후크 모델링에는 후크, 해당 속성 및 속성을 정의하는 스키마를 생성하는 작업이 포함됩니다. 이 자습서에서는 Python을 사용하여 사용자 지정 후크를 모델링하는 방법을 안내합니다.

## 1단계: 후크 프로젝트 패키지 생성
<a name="model-hook-project-package-python"></a>

후크 프로젝트 패키지를 생성합니다. CloudFormation CLI는 후크 사양에 정의된 대상 수명 주기의 특정 후크 작업에 해당하는 빈 핸들러 함수를 생성합니다.

```
cfn generate
```

명령은 다음 출력을 반환합니다.

```
Generated files for MyCompany::Testing::MyTestHook
```

**참고**  
더 이상 사용되지 않는 버전을 사용하지 않도록 Lambda 런타임이 up-to-date 상태인지 확인합니다. 자세한 내용은 [리소스 유형 및 후크에 대한 Lambda 런타임 업데이트를 참조하세요](https://docs.aws.amazon.com/cloudformation-cli/latest/userguide/runtime-update.html).

## 2단계: 후크 핸들러 추가
<a name="model-hook-project-add-handler"></a>

구현하도록 선택한 핸들러에 자체 후크 핸들러 런타임 코드를 추가합니다. 예를 들어 로깅을 위해 다음 코드를 추가할 수 있습니다.

```
LOG.setLevel(logging.INFO)
LOG.info("Internal testing Hook triggered for target: " + request.hookContext.targetName);
```

CloudFormation CLI는에서 `src/models.py` 파일을 생성합니다[후크 구성 스키마 구문 참조](hook-configuration-schema.md).

**Example models.py**  

```
import sys
from dataclasses import dataclass
from inspect import getmembers, isclass
from typing import (
    AbstractSet,
    Any,
    Generic,
    Mapping,
    MutableMapping,
    Optional,
    Sequence,
    Type,
    TypeVar,
)

from cloudformation_cli_python_lib.interface import (
    BaseModel,
    BaseHookHandlerRequest,
)
from cloudformation_cli_python_lib.recast import recast_object
from cloudformation_cli_python_lib.utils import deserialize_list

T = TypeVar("T")


def set_or_none(value: Optional[Sequence[T]]) -> Optional[AbstractSet[T]]:
    if value:
        return set(value)
    return None


@dataclass
class HookHandlerRequest(BaseHookHandlerRequest):
    pass


@dataclass
class TypeConfigurationModel(BaseModel):
    limitSize: Optional[str]
    cidr: Optional[str]
    encryptionAlgorithm: Optional[str]

    @classmethod
    def _deserialize(
        cls: Type["_TypeConfigurationModel"],
        json_data: Optional[Mapping[str, Any]],
    ) -> Optional["_TypeConfigurationModel"]:
        if not json_data:
            return None
        return cls(
            limitSize=json_data.get("limitSize"),
            cidr=json_data.get("cidr"),
            encryptionAlgorithm=json_data.get("encryptionAlgorithm"),
        )


_TypeConfigurationModel = TypeConfigurationModel
```

## 3단계: 후크 핸들러 구현
<a name="model-hook-project-code-handler-python"></a>

Python 데이터 클래스가 생성되면 후크의 기능을 실제로 구현하는 핸들러를 작성할 수 있습니다. 이 예제에서는 핸들러에 대한 `preCreate``preUpdate`, 및 `preDelete` 호출 지점을 구현합니다.

**Topics**
+ [preCreate 핸들러 구현](#model-hook-project-code-handler-python-precreate)
+ [preUpdate 핸들러 구현](#model-hook-project-code-handler-python-preupdate)
+ [preDelete 핸들러 구현](#model-hook-project-code-handler-python-predelete)
+ [후크 핸들러 구현](#model-hook-project-code-handler-python-hook-handler)

### preCreate 핸들러 구현
<a name="model-hook-project-code-handler-python-precreate"></a>

`preCreate` 핸들러는 `AWS::S3::Bucket ` 또는 `AWS::SQS::Queue` 리소스에 대한 서버 측 암호화 설정을 확인합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음이 true인 경우에만 전달합니다.
  + Amazon S3 버킷 암호화가 설정되어 있습니다.
  + 버킷에 대해 Amazon S3 버킷 키가 활성화됩니다.
  + Amazon S3 버킷에 설정된 암호화 알고리즘이 필요한 올바른 알고리즘입니다.
  +  AWS Key Management Service 키 ID가 설정됩니다.
+ `AWS::SQS::Queue` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  +  AWS Key Management Service 키 ID가 설정됩니다.

### preUpdate 핸들러 구현
<a name="model-hook-project-code-handler-python-preupdate"></a>

`preUpdate` 핸들러에서 지정된 모든 대상에 대한 업데이트 작업 전에 시작하는 핸들러를 구현합니다. `preUpdate` 핸들러는 다음을 수행합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  + Amazon S3 버킷의 버킷 암호화 알고리즘이 수정되지 않았습니다.

### preDelete 핸들러 구현
<a name="model-hook-project-code-handler-python-predelete"></a>

`preDelete` 핸들러에서 지정된 모든 대상에 대한 삭제 작업 전에 시작하는 핸들러를 구현합니다. `preDelete` 핸들러는 다음을 수행합니다.
+ `AWS::S3::Bucket` 리소스의 경우 후크는 다음과 같은 경우에만 전달합니다.
  + 리소스를 삭제한 후 계정에 필요한 최소 규정 준수 리소스가 존재하는지 확인합니다.
  + 필요한 최소 규정 준수 리소스 양은 후크의 구성에서 설정됩니다.

### 후크 핸들러 구현
<a name="model-hook-project-code-handler-python-hook-handler"></a>

1. IDE에서 `src` 폴더에 있는 `handlers.py` 파일을 엽니다.

1. `handlers.py` 파일의 전체 내용을 다음 코드로 바꿉니다.  
**Example handlers.py**  

   ```
   import logging
   from typing import Any, MutableMapping, Optional
   import botocore
   
   from cloudformation_cli_python_lib import (
       BaseHookHandlerRequest,
       HandlerErrorCode,
       Hook,
       HookInvocationPoint,
       OperationStatus,
       ProgressEvent,
       SessionProxy,
       exceptions,
   )
   
   from .models import HookHandlerRequest, TypeConfigurationModel
   
   # Use this logger to forward log messages to CloudWatch Logs.
   LOG = logging.getLogger(__name__)
   TYPE_NAME = "MyCompany::Testing::MyTestHook"
   
   LOG.setLevel(logging.INFO)
   
   hook = Hook(TYPE_NAME, TypeConfigurationModel)
   test_entrypoint = hook.test_entrypoint
   
   
   def _validate_s3_bucket_encryption(
       bucket: MutableMapping[str, Any], required_encryption_algorithm: str
   ) -> ProgressEvent:
       status = None
       message = ""
       error_code = None
   
       if bucket:
           bucket_name = bucket.get("BucketName")
   
           bucket_encryption = bucket.get("BucketEncryption")
           if bucket_encryption:
               server_side_encryption_rules = bucket_encryption.get(
                   "ServerSideEncryptionConfiguration"
               )
               if server_side_encryption_rules:
                   for rule in server_side_encryption_rules:
                       bucket_key_enabled = rule.get("BucketKeyEnabled")
                       if bucket_key_enabled:
                           server_side_encryption_by_default = rule.get(
                               "ServerSideEncryptionByDefault"
                           )
   
                           encryption_algorithm = server_side_encryption_by_default.get(
                               "SSEAlgorithm"
                           )
                           kms_key_id = server_side_encryption_by_default.get(
                               "KMSMasterKeyID"
                           )  # "KMSMasterKeyID" is name of the property for an AWS::S3::Bucket
   
                           if encryption_algorithm == required_encryption_algorithm:
                               if encryption_algorithm == "aws:kms" and not kms_key_id:
                                   status = OperationStatus.FAILED
                                   message = f"KMS Key ID not set for bucket with name: f{bucket_name}"
                               else:
                                   status = OperationStatus.SUCCESS
                                   message = f"Successfully invoked PreCreateHookHandler for AWS::S3::Bucket with name: {bucket_name}"
                           else:
                               status = OperationStatus.FAILED
                               message = f"SSE Encryption Algorithm is incorrect for bucket with name: {bucket_name}"
                       else:
                           status = OperationStatus.FAILED
                           message = f"Bucket key not enabled for bucket with name: {bucket_name}"
   
                       if status == OperationStatus.FAILED:
                           break
               else:
                   status = OperationStatus.FAILED
                   message = f"No SSE Encryption configurations for bucket with name: {bucket_name}"
           else:
               status = OperationStatus.FAILED
               message = (
                   f"Bucket Encryption not enabled for bucket with name: {bucket_name}"
               )
       else:
           status = OperationStatus.FAILED
           message = "Resource properties for S3 Bucket target model are empty"
   
       if status == OperationStatus.FAILED:
           error_code = HandlerErrorCode.NonCompliant
   
       return ProgressEvent(status=status, message=message, errorCode=error_code)
   
   
   def _validate_sqs_queue_encryption(queue: MutableMapping[str, Any]) -> ProgressEvent:
       if not queue:
           return ProgressEvent(
               status=OperationStatus.FAILED,
               message="Resource properties for SQS Queue target model are empty",
               errorCode=HandlerErrorCode.NonCompliant,
           )
       queue_name = queue.get("QueueName")
   
       kms_key_id = queue.get(
           "KmsMasterKeyId"
       )  # "KmsMasterKeyId" is name of the property for an AWS::SQS::Queue
       if not kms_key_id:
           return ProgressEvent(
               status=OperationStatus.FAILED,
               message=f"Server side encryption turned off for queue with name: {queue_name}",
               errorCode=HandlerErrorCode.NonCompliant,
           )
   
       return ProgressEvent(
           status=OperationStatus.SUCCESS,
           message=f"Successfully invoked PreCreateHookHandler for targetAWS::SQS::Queue with name: {queue_name}",
       )
   
   
   @hook.handler(HookInvocationPoint.CREATE_PRE_PROVISION)
   def pre_create_handler(
       session: Optional[SessionProxy],
       request: HookHandlerRequest,
       callback_context: MutableMapping[str, Any],
       type_configuration: TypeConfigurationModel,
   ) -> ProgressEvent:
       target_name = request.hookContext.targetName
       if "AWS::S3::Bucket" == target_name:
           return _validate_s3_bucket_encryption(
               request.hookContext.targetModel.get("resourceProperties"),
               type_configuration.encryptionAlgorithm,
           )
       elif "AWS::SQS::Queue" == target_name:
           return _validate_sqs_queue_encryption(
               request.hookContext.targetModel.get("resourceProperties")
           )
       else:
           raise exceptions.InvalidRequest(f"Unknown target type: {target_name}")
   
   
   def _validate_bucket_encryption_rules_not_updated(
       resource_properties, previous_resource_properties
   ) -> ProgressEvent:
       bucket_encryption_configs = resource_properties.get("BucketEncryption", {}).get(
           "ServerSideEncryptionConfiguration", []
       )
       previous_bucket_encryption_configs = previous_resource_properties.get(
           "BucketEncryption", {}
       ).get("ServerSideEncryptionConfiguration", [])
   
       if len(bucket_encryption_configs) != len(previous_bucket_encryption_configs):
           return ProgressEvent(
               status=OperationStatus.FAILED,
               message=f"Current number of bucket encryption configs does not match previous. Current has {str(len(bucket_encryption_configs))} configs while previously there were {str(len(previous_bucket_encryption_configs))} configs",
               errorCode=HandlerErrorCode.NonCompliant,
           )
   
       for i in range(len(bucket_encryption_configs)):
           current_encryption_algorithm = (
               bucket_encryption_configs[i]
               .get("ServerSideEncryptionByDefault", {})
               .get("SSEAlgorithm")
           )
           previous_encryption_algorithm = (
               previous_bucket_encryption_configs[i]
               .get("ServerSideEncryptionByDefault", {})
               .get("SSEAlgorithm")
           )
   
           if current_encryption_algorithm != previous_encryption_algorithm:
               return ProgressEvent(
                   status=OperationStatus.FAILED,
                   message=f"Bucket Encryption algorithm can not be changed once set. The encryption algorithm was changed to {current_encryption_algorithm} from {previous_encryption_algorithm}.",
                   errorCode=HandlerErrorCode.NonCompliant,
               )
   
       return ProgressEvent(
           status=OperationStatus.SUCCESS,
           message="Successfully invoked PreUpdateHookHandler for target: AWS::SQS::Queue",
       )
   
   
   def _validate_queue_encryption_not_disabled(
       resource_properties, previous_resource_properties
   ) -> ProgressEvent:
       if previous_resource_properties.get(
           "KmsMasterKeyId"
       ) and not resource_properties.get("KmsMasterKeyId"):
           return ProgressEvent(
               status=OperationStatus.FAILED,
               errorCode=HandlerErrorCode.NonCompliant,
               message="Queue encryption can not be disable",
           )
       else:
           return ProgressEvent(status=OperationStatus.SUCCESS)
   
   
   @hook.handler(HookInvocationPoint.UPDATE_PRE_PROVISION)
   def pre_update_handler(
       session: Optional[SessionProxy],
       request: BaseHookHandlerRequest,
       callback_context: MutableMapping[str, Any],
       type_configuration: MutableMapping[str, Any],
   ) -> ProgressEvent:
       target_name = request.hookContext.targetName
       if "AWS::S3::Bucket" == target_name:
           resource_properties = request.hookContext.targetModel.get("resourceProperties")
           previous_resource_properties = request.hookContext.targetModel.get(
               "previousResourceProperties"
           )
   
           return _validate_bucket_encryption_rules_not_updated(
               resource_properties, previous_resource_properties
           )
       elif "AWS::SQS::Queue" == target_name:
           resource_properties = request.hookContext.targetModel.get("resourceProperties")
           previous_resource_properties = request.hookContext.targetModel.get(
               "previousResourceProperties"
           )
   
           return _validate_queue_encryption_not_disabled(
               resource_properties, previous_resource_properties
           )
       else:
           raise exceptions.InvalidRequest(f"Unknown target type: {target_name}")
   ```

다음 항목인 [에 사용자 지정 후크 등록 CloudFormation](registering-hooks.md) 단원으로 이동합니다.