/l3-trip-logger

Primary LanguageTypeScript

Test the Amplify GraphQL API L3 CDK construct (pre-alpha)

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DO NOT USE IN PRODUCTION ENVIRONMENTS - FOR TESTING ONLY

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This is a sample repository showcasing the Amplify GraphQL API L3 CDK construct (pre-alpha) in action. It allows you to leverage all the benefits of the Amplify GraphQL directives (@model, @auth, etc.) via CDK.

Key features

  • 🔗 GraphQL APIs and connected DynamoDB tables with a single schema
    • Use the @model directive from Amplify to generate both an AppSync API with CRUDL operations and their connected DynamoDB sources. A five line GraphQL schema in Amplify would’ve taken hundreds of lines of code and multiple files to write previously.
  • 🤯 Use all Amplify GraphQL directives such as @auth
    • Instead of hand-authoring hundreds of lines of JS/VTL resolver code to handle your app’s authorization needs, you can now leverage Amplify’s @auth directive to enforce owner-based authorization, group-authorization with just a single line of code. Don’t worry, you can still write JS/VTL resolver code you if you’d like.
    • This is great for customers that want the ergonomics of Amplify’s GraphQL capabilities but don’t want to setup the Amplify CLI or use CDK tooling already.
  • 🚀 Escape hatches built-in
    • access/modify all the generated resources as L2 constructs directly from within CDK. No separate build step required.
    • The construct returns an object that contains a resources key. In which you’ll find the L1 and L2 constructs that it generates for resources such as AppSync API, DynamoDB tables, etc.
  • 🧑‍💻 Works seamlessly with the rest of the CDK tooling
    • In our sample code below, you’ll see how easy it is to combine L2 Lambda Function CDK constructs with the Amplify GraphQL L3 constructs.
    • Yes. It works with CDK pipelines.

What's deployed as part of this demo?

  1. A Blog DynamoDB table with authorization rules permitting anyone with an API Key to Create/Read/Update/Delete the items to the table.
  2. A echo query that returns whatever string is sent to it using a Lambda function handler.
  3. A sendEmail mutation that publishes an SNS event with an email subscription using JavaScript resolvers.
  4. A PubSub API (Mutation.publish, Subscription.subscribe) with that allows anyone to publish/subscribe based on a channel & pass freeform data. Uses VTL resolvers.

Quick tour of lib/backend-stack.ts

Go to lib/backend-stack.ts to start exploring the code base:

  • lib/backend-stack.ts includes the AmplifyGraphQlApi CDK construct. You can pass in any schema that works with the Amplify CLI today.
  • lib/mappings include the resolver mapping templates and functions. The publish.req.vtl and publish.res.vtl files are the required files for a basic PubSub application. See addPubSubHandler() for sample code.
  • addSNSTopicHandler() showcases how to use the escape hatch to connect the generated L2 construct with additional resources within your AWS account such as an SNS topic. IMPORTANT: make sure to enter your email into the ENTER_YOUR_EMAIL_HERE to receive the SNS notifications

Still work-in-progress items

  • Final API namings and shapes
  • First-class mechanism to author custom resolver code (right now you still need to escape hatch to the L1/L2 constructs)
  • Generate client configurations and GraphQL client code for Amplify libraries
  • Support to work in conjunction with Amplify Studio

Useful commands

  • cdk watch --hotswap-fallback watches and deploy ongoing file changes
  • cdk deploy deploy this stack to your default AWS account/region
  • cdk diff compare deployed stack with current state
  • cdk synth emits the synthesized CloudFormation template