feat(serverless): add AWS::Serverless::Application to CFN spec

[sam-goodwin]

Fixes #1602

This change adds support for deploying serverless applications from SAR as part of a CDK application:

• Synchronizes sam_spec from goformation as of [Fix] Add Application.Location and fix SSEEnabled awslabs/goformation#166 - brings in AWS::Serverless::Application and AWS::Serverless:LayerVersion.
• Adds CAPABILITY_AUTO_EXPAND capability to change-sets deployed via the toolkit
• Adds RefKind for AWS::Serverless::Application and AWS::Serverless:LayerVersion.

Example usage:

const app = new cdk.App();
const stack = new cdk.Stack(app, 'serverless');

const processor = new lambda.Function(stack, 'Function', {
  code: lambda.Code.inline('exports.handler = async (event) => console.log(event)'),
  handler: 'index.handler',
  runtime: lambda.Runtime.NodeJS810
});

new CfnApplication(stack, 'App', {
  location: {
    applicationId: 'arn:aws:serverlessrepo:us-east-1:077246666028:applications/aws-serverless-twitter-event-source',
    semanticVersion: '2.0.0'
  },
  parameters: {
    SearchText: '#serverless -filter:nativeretweets',
    TweetProcessorFunctionName: processor.functionName
  }
});

---

Pull Request Checklist

• Testing
  • Unit test added
  • CLI change?: coordinate update of integration tests with team
  • cdk-init template change?: coordinated update of integration tests with team
• Docs
  • jsdocs: All public APIs documented
  • README: README and/or documentation topic updated
• Title and Description
  • Change type: title prefixed with fix, feat will appear in changelog
  • Title: use lower-case and doesn't end with a period
  • Breaking?: last paragraph: "BREAKING CHANGE: <describe what changed + link for details>"
  • Issues: Indicate issues fixed via: "Fixes #xxx" or "Closes #xxx"
• Sensitive Modules (requires 2 PR approvers)
  • IAM Policy Document (in @aws-cdk/aws-iam)
  • EC2 Security Groups and ACLs (in @aws-cdk/aws-ec2)
  • Grant APIs (only if not based on official documentation with a reference)

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license.

[eladb]

@sam-goodwin any updates?

[eladb]

Looks great!

Maybe you can write a small unit test in the @aws-cdk/aws-serverless library that plays with this L1 a little bit?

[jlhood]

Thanks for doing this!

[sam-goodwin]

I tested this and it synthesizes "fine", but it doesn't add the Transform to the template so cdk deploy fails. The toolkit needs to detect use of SAM resources and apply the transform.

[sam-goodwin]

Ah, it needs "RequiredTransform": "AWS::Serverless-2016-10-31" to be set.

[sam-goodwin]

Fixed the transform but then ran into:

4/5 | 22:34:47 | CREATE_FAILED | AWS::CloudFormation::Stack | App Requires capabilities : [CAPABILITY_AUTO_EXPAND]

Also, goformation has been updated with the missing resources: awslabs/goformation#163, but the spec is actually wrong. I submitted a PR with a fix: awslabs/goformation#166

Copy @PaulMaddox