ASK CLI(v2)から、AWS CloudFormationでAlexa Skillのバックエンドをデプロイできるようになりました。

プロジェクトを作成する

プロジェクトの作成はv1同様ask newから対話的に始めることができます。

Step1: 言語を指定する

% ask new
Please follow the wizard to start your Alexa skill project ->
? Choose the programming language you will use to code your skill:  (Use arrow keys)
❯ NodeJS 
  Python 
  Java 

Step2: バックエンドのデプロイ先・方法を指定する

V1ではLambdaデプロイオンリーでしたが、v2ではHosted / AWS CloudFormation / AWS Lambda / self-hostedから選ぶことができます。

? Choose a method to host your skill's backend resources:  (Use arrow keys)
❯ Alexa-hosted skills
  Host your skill code by Alexa (free). 
  AWS with CloudFormation
  Host your skill code with AWS services and provision with AWS CloudFormation (requires AWS account) 
  AWS Lambda
  Host your skill code on AWS Lambda (requires AWS account). 
  ──────────────
  self-hosted and manage your own hosting 

Step3: ベースのテンプレートを指定する

サンプルスキルを選びましょう。

? Choose a template to start with:  (Use arrow keys)
❯ Hello world           Alexa's hello world skill to send the greetings to the world! 
  Fact skill            Quick sample skill to manage a collection of voice data. 
  High low game         Guess a number high or low using persistent attributes. Make sure your AWS account has the permission to manage DynamoDB! 

Step4: スキル・プロジェクト名を指定する

ディレクトリ名やスキル名を指定して完了です。

? Please type in your skill name:  example-skill
? Please type in your folder name for the skill project (alphanumeric):  exampleSkill

AWS CloudFormationを選んだ場合のディレクトリ構成がこちらです。

% tree 
.
├── LICENSE.txt
├── ask-resources.json
├── infrastructure
│   └── cfn-deployer
│       └── skill-stack.yaml
├── lambda
│   ├── index.js
│   ├── package.json
│   └── util.js
└── skill-package
    ├── assets
    │   ├── en-US_largeIcon.png
    │   └── en-US_smallIcon.png
    ├── interactionModels
    │   └── custom
    │       └── en-US.json
    └── skill.json

7 directories, 10 files

デプロイ

デプロイ方法もv1と同じで、ask deployを実行しましょう。

CloudFormationのリソースをチェックする

.ask/ask-states.jsonにデプロイしたCloudFormationのstack idがあります。

なのでAWS CLI + jqでこのようにすることでスタック情報を取得できます。

% aws cloudformation describe-stack-resources --stack-name $(cat .ask/ask-states.json | jq ".profiles.default.skillInfrastructure["@ask-cli/cfn-deployer"].deployState.default.stackId" -r) | jq .
{
  "StackResources": [
    {
      "StackName": "example-skill-default-skillStack-1587380830650",
      "StackId": "arn:aws:cloudformation:us-east-1:99999999:stack/example-skill-default-skillStack-1587380830650/1e4f54f0-82f7-11ea-86a4-0eb40de15aba",
      "LogicalResourceId": "AlexaSkillFunction",
      "PhysicalResourceId": "example-skill-default-skillSt-AlexaSkillFunction-19SAEJO5SZMBP",
      "ResourceType": "AWS::Lambda::Function",
      "Timestamp": "2020-04-20T11:07:47.639Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },
    {
      "StackName": "example-skill-default-skillStack-1587380830650",
      "StackId": "arn:aws:cloudformation:us-east-1:99999999:stack/example-skill-default-skillStack-1587380830650/1e4f54f0-82f7-11ea-86a4-0eb40de15aba",
      "LogicalResourceId": "AlexaSkillFunctionEventPermission",
      "PhysicalResourceId": "example-skill-default-skillStack-1587380830650-AlexaSkillFunctionEventPermission-14T7X7Q1K8HFM",
      "ResourceType": "AWS::Lambda::Permission",
      "Timestamp": "2020-04-20T11:08:00.883Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },
    {
      "StackName": "example-skill-default-skillStack-1587380830650",
      "StackId": "arn:aws:cloudformation:us-east-1:99999999:stack/example-skill-default-skillStack-1587380830650/1e4f54f0-82f7-11ea-86a4-0eb40de15aba",
      "LogicalResourceId": "AlexaSkillIAMRole",
      "PhysicalResourceId": "example-skill-default-skillSta-AlexaSkillIAMRole-YFXEA2L5SOA4",
      "ResourceType": "AWS::IAM::Role",
      "Timestamp": "2020-04-20T11:07:44.055Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    }
  ]
}

AWS CloudFormationのカスタマイズ

AWS CloudFormation / AWS SAMでスタックをカスタマイズできます。

下の例では、 S3:GetObject をLambdaが実行できるようにカスタムしています。

AWSTemplateFormatVersion: 2010-09-09
Parameters:
  SkillId:
    Type: String
  LambdaRuntime:
    Type: String
  LambdaHandler:
    Type: String
  CodeBucket:
    Type: String
  CodeKey:
    Type: String
  CodeVersion:
    Type: String
Resources:
  AlexaSkillIAMRole:
      Type: AWS::IAM::Role
      Properties:
        AssumeRolePolicyDocument:
          Version: 2012-10-17
          Statement:
            - Effect: Allow
              Principal:
                Service:
                  - lambda.amazonaws.com
              Action:
                - sts:AssumeRole
        Path: /
        Policies:
          - PolicyName: alexaExternalPolicy
            PolicyDocument:
              Version: 2012-10-17
              Statement:
                - Effect: Allow
                  Action:
                    - s3:GetObject
                  Resource: arn:aws:s3:::*
          - PolicyName: alexaSkillExecutionPolicy
            PolicyDocument:
              Version: 2012-10-17
              Statement:
                - Effect: Allow
                  Action:
                    - logs:*
                  Resource: arn:aws:logs:*:*:*
  AlexaSkillFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        S3Bucket: !Ref CodeBucket
        S3Key: !Ref CodeKey
        S3ObjectVersion: !Ref CodeVersion
      Handler: !Ref LambdaHandler
      Runtime: !Ref LambdaRuntime
      Role: !GetAtt AlexaSkillIAMRole.Arn
      MemorySize: 512
      Timeout: 60
  AlexaSkillFunctionEventPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:invokeFunction
      FunctionName: !GetAtt AlexaSkillFunction.Arn
      Principal: alexa-appkit.amazon.com
      EventSourceToken: !Ref SkillId
Outputs:
  SkillEndpoint:
    Description: LambdaARN for the regional endpoint
    Value: !GetAtt AlexaSkillFunction.Arn

Conclusion

ASK CLI(v2)でAWS CloudFormationを使うことで、AWSのリソースを複数組み合わせて動かすスキルなども簡単にデプロイ・管理できるようになりそうです。