Testing Hooks in your AWS account

Now that you've coded your handler functions that correspond to an invocation point, it's time to test your Hook on a CloudFormation stack.

In Implementing Hook handlers, the Hook failure mode was set to FAIL if the CloudFormation template didn't provision an S3 bucket with the following:

The Amazon S3 bucket encryption is set.
The Amazon S3 bucket key is enabled for the bucket.
The encryption algorithm set for the Amazon S3 bucket is the correct algorithm required.
The AWS Key Management Service key ID is set.

In the following example, create a template called my-failed-bucket-stack.yml with a stack name of my-hook-stack that fails the stack configuration and stops before the resource provisions.

Testing Hooks by provisioning a stack

To provision a stack (example 1)

Provision a non-compliant stack

Author a template that specifies an S3 bucket. For example, my-failed-bucket-stack.yml.


AWSTemplateFormatVersion: 2010-09-09
Resources:
  S3Bucket:
    Type: 'AWS::S3::Bucket'
    Properties: {}

Create a stack, and specify your template in the AWS Command Line Interface (AWS CLI). In the following example, specify the stack name as my-hook-stack and the template name as my-failed-bucket-stack.yml.
```
$ aws cloudformation create-stack \
  --stack-name my-hook-stack \
  --template-body file://my-failed-bucket-stack.yml
```

(Optional) View your stack progress by specifying your stack name. In the following example, specify the stack name my-hook-stack.


$ aws cloudformation describe-stack-events \
  --stack-name my-hook-stack

Use the describe-stack-events operation to see the Hook failure while creating the bucket. The following is an example output of the command.


{
    "StackEvents": [
    ...
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-hook-stack/2c693970-f57e-11eb-a0fb-061a2a83f0b9",
            "EventId": "S3Bucket-CREATE_FAILED-2021-08-04T23:47:03.305Z",
            "StackName": "my-hook-stack",
            "LogicalResourceId": "S3Bucket",
            "PhysicalResourceId": "",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:47:03.305000+00:00",
            "ResourceStatus": "CREATE_FAILED",
            "ResourceStatusReason": "The following hook(s) failed: [MyCompany::Testing::MyTestHook]",
            "ResourceProperties": "{}",
            "ClientRequestToken": "Console-CreateStack-abe71ac2-ade4-a762-0499-8d34d91d6a92"
        },
    ...
    ]
}

Results: The Hook invocation failed the stack configuration and stopped the resource from provisioning.

Use a CloudFormation template to pass Hook validation

To create a stack and pass the Hook validation, update the template so that your resource uses an encrypted S3 bucket. This example uses the template my-encrypted-bucket-stack.yml.


AWSTemplateFormatVersion: 2010-09-09
Description: |
  This CloudFormation template provisions an encrypted S3 Bucket
Resources:
  EncryptedS3Bucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Sub 'encryptedbucket-${AWS::Region}-${AWS::AccountId}'
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: 'aws:kms'
              KMSMasterKeyID: !Ref EncryptionKey
            BucketKeyEnabled: true
  EncryptionKey:
    Type: 'AWS::KMS::Key'
    DeletionPolicy: Retain
    Properties:
      Description: KMS key used to encrypt the resource type artifacts
      EnableKeyRotation: true
      KeyPolicy:
        Version: 2012-10-17
        Statement:
          - Sid: Enable full access for owning account
            Effect: Allow
            Principal:
              AWS: !Ref 'AWS::AccountId'
            Action: 'kms:*'
            Resource: '*'
Outputs:
  EncryptedBucketName:
    Value: !Ref EncryptedS3Bucket

Note

Hooks won't be invoked for skipped resources.

Create a stack and specify your template. In this example, the stack name is my-encrypted-bucket-stack.


$ aws cloudformation create-stack \
  --stack-name my-encrypted-bucket-stack \
  --template-body file://my-encrypted-bucket-stack.yml \

(Optional) View your stack progress by specifying the stack name.


$ aws cloudformation describe-stack-events \
  --stack-name my-encrypted-bucket-stack

Use the describe-stack-events command to view the response. The following is an example of the describe-stack-events command.


{
    "StackEvents": [
    ...
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-CREATE_COMPLETE-2021-08-04T23:23:20.973Z",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "encryptedbucket-us-west-2-ACCOUNT_ID",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:23:20.973000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "ResourceProperties": "{\"BucketName\":\"encryptedbucket-us-west-2-071617338693\",\"BucketEncryption\":{\"ServerSideEncryptionConfiguration\":[{\"BucketKeyEnabled\":\"true\",\"ServerSideEncryptionByDefault\":{\"SSEAlgorithm\":\"aws:kms\",\"KMSMasterKeyID\":\"ENCRYPTION_KEY_ARN\"}}]}}",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-CREATE_IN_PROGRESS-2021-08-04T23:22:59.410Z",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "encryptedbucket-us-west-2-ACCOUNT_ID",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:22:59.410000+00:00",
            "ResourceStatus": "CREATE_IN_PROGRESS",
            "ResourceStatusReason": "Resource creation Initiated",
            "ResourceProperties": "{\"BucketName\":\"encryptedbucket-us-west-2-071617338693\",\"BucketEncryption\":{\"ServerSideEncryptionConfiguration\":[{\"BucketKeyEnabled\":\"true\",\"ServerSideEncryptionByDefault\":{\"SSEAlgorithm\":\"aws:kms\",\"KMSMasterKeyID\":\"ENCRYPTION_KEY_ARN\"}}]}}",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-6516081f-c1f2-4bfe-a0f0-cefa28679994",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:22:58.349000+00:00",
            "ResourceStatus": "CREATE_IN_PROGRESS",
            "ResourceStatusReason": "Hook invocations complete.  Resource creation initiated",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
    ...
    ]
}

Results: CloudFormation successfully created the stack. The Hook's logic verified that the AWS::S3::Bucket resource contained server-side encryption before provisioning the resource.

To provision a stack (example 2)

Provision a non-compliant stack

Author a template that specifies an S3 bucket. For example aes256-bucket.yml.


AWSTemplateFormatVersion: 2010-09-09
Description: |
  This CloudFormation template provisions an encrypted S3 Bucket
Resources:
  EncryptedS3Bucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Sub 'encryptedbucket-${AWS::Region}-${AWS::AccountId}'
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: AES256
            BucketKeyEnabled: true
Outputs:
  EncryptedBucketName:
    Value: !Ref EncryptedS3Bucket

Create a stack, and specify your template in the AWS CLI. In the following example, specify the stack name as my-hook-stack and the template name as aes256-bucket.yml.
```
$ aws cloudformation create-stack \
  --stack-name my-hook-stack \
  --template-body file://aes256-bucket.yml
```

(Optional) View your stack progress by specifying your stack name. In the following example, specify the stack name my-hook-stack.


$ aws cloudformation describe-stack-events \
  --stack-name my-hook-stack

Use the describe-stack-events operation to see the Hook failure while creating the bucket. The following is an example output of the command.


{
    "StackEvents": [
    ...
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-hook-stack/2c693970-f57e-11eb-a0fb-061a2a83f0b9",
            "EventId": "S3Bucket-CREATE_FAILED-2021-08-04T23:47:03.305Z",
            "StackName": "my-hook-stack",
            "LogicalResourceId": "S3Bucket",
            "PhysicalResourceId": "",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:47:03.305000+00:00",
            "ResourceStatus": "CREATE_FAILED",
            "ResourceStatusReason": "The following hook(s) failed: [MyCompany::Testing::MyTestHook]",
            "ResourceProperties": "{}",
            "ClientRequestToken": "Console-CreateStack-abe71ac2-ade4-a762-0499-8d34d91d6a92"
        },
    ...
    ]
}

Results: The Hook invocation failed the stack configuration and stopped the resource from provisioning. The stack failed due to the S3 bucket encryption configured incorrectly. The Hook type configuration requires aws:kms while this bucket uses AES256.

Use a CloudFormation template to pass Hook validation

To create a stack and pass the Hook validation, update the template so that your resource uses an encrypted S3 bucket. This example uses the template kms-bucket-and-queue.yml.


AWSTemplateFormatVersion: 2010-09-09
Description: |
  This CloudFormation template provisions an encrypted S3 Bucket
Resources:
  EncryptedS3Bucket:
    Type: 'AWS::S3::Bucket'
    Properties:
      BucketName: !Sub 'encryptedbucket-${AWS::Region}-${AWS::AccountId}'
      BucketEncryption:
        ServerSideEncryptionConfiguration:
          - ServerSideEncryptionByDefault:
              SSEAlgorithm: 'aws:kms'
              KMSMasterKeyID: !Ref EncryptionKey
            BucketKeyEnabled: true
  EncryptedQueue:
    Type: 'AWS::SQS::Queue'
    Properties:
      QueueName: 'encryptedqueue-${AWS::Region}-${AWS::AccountId}'
      KmsMasterKeyId: !Ref EncryptionKey
  EncryptionKey:
    Type: 'AWS::KMS::Key'
    DeletionPolicy: Retain
    Properties:
      Description: KMS key used to encrypt the resource type artifacts
      EnableKeyRotation: true
      KeyPolicy:
        Version: 2012-10-17
        Statement:
          - Sid: Enable full access for owning account
            Effect: Allow
            Principal:
              AWS: !Ref 'AWS::AccountId'
            Action: 'kms:*'
            Resource: '*'
Outputs:
  EncryptedBucketName:
    Value: !Ref EncryptedS3Bucket
  EncryptedQueueName:
    Value: !Ref EncryptedQueue

Note

Hooks won't be invoked for skipped resources.

Create a stack and specify your template. In this example, the stack name is my-encrypted-bucket-stack.


$ aws cloudformation create-stack \
  --stack-name my-encrypted-bucket-stack \
  --template-body file://kms-bucket-and-queue.yml

(Optional) View your stack progress by specifying the stack name.


$ aws cloudformation describe-stack-events \
  --stack-name my-encrypted-bucket-stack

Use the describe-stack-events command to view the response. The following is an example of the describe-stack-events command.


{
    "StackEvents": [
    ...
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-CREATE_COMPLETE-2021-08-04T23:23:20.973Z",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "encryptedbucket-us-west-2-ACCOUNT_ID",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:23:20.973000+00:00",
            "ResourceStatus": "CREATE_COMPLETE",
            "ResourceProperties": "{\"BucketName\":\"encryptedbucket-us-west-2-071617338693\",\"BucketEncryption\":{\"ServerSideEncryptionConfiguration\":[{\"BucketKeyEnabled\":\"true\",\"ServerSideEncryptionByDefault\":{\"SSEAlgorithm\":\"aws:kms\",\"KMSMasterKeyID\":\"ENCRYPTION_KEY_ARN\"}}]}}",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-CREATE_IN_PROGRESS-2021-08-04T23:22:59.410Z",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "encryptedbucket-us-west-2-ACCOUNT_ID",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:22:59.410000+00:00",
            "ResourceStatus": "CREATE_IN_PROGRESS",
            "ResourceStatusReason": "Resource creation Initiated",
            "ResourceProperties": "{\"BucketName\":\"encryptedbucket-us-west-2-071617338693\",\"BucketEncryption\":{\"ServerSideEncryptionConfiguration\":[{\"BucketKeyEnabled\":\"true\",\"ServerSideEncryptionByDefault\":{\"SSEAlgorithm\":\"aws:kms\",\"KMSMasterKeyID\":\"ENCRYPTION_KEY_ARN\"}}]}}",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
        {
            "StackId": "arn:aws:cloudformation:us-west-2:ACCOUNT_ID:stack/my-encrypted-bucket-stack/82a97150-f57a-11eb-8eb2-06a6bdcc7779",
            "EventId": "EncryptedS3Bucket-6516081f-c1f2-4bfe-a0f0-cefa28679994",
            "StackName": "my-encrypted-bucket-stack",
            "LogicalResourceId": "EncryptedS3Bucket",
            "PhysicalResourceId": "",
            "ResourceType": "AWS::S3::Bucket",
            "Timestamp": "2021-08-04T23:22:58.349000+00:00",
            "ResourceStatus": "CREATE_IN_PROGRESS",
            "ResourceStatusReason": "Hook invocations complete.  Resource creation initiated",
            "ClientRequestToken": "Console-CreateStack-39df35ac-ca00-b7f6-5661-4e917478d075"
        },
    ...
    ]
}

Results: CloudFormation successfully created the stack. The Hook's logic verified that the AWS::S3::Bucket resource contained server-side encryption before provisioning the resource.

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