cdk-aws-appsync-events

CDK app that deploys an AppSync Event API with Lambda and DynamoDB data source integrations.

Prerequisites

• AWS:
  • Must have authenticated with Default Credentials in your local environment.
  • Must have completed the CDK bootstrapping for the target AWS environment.
• Node.js + npm:
  • Must be installed in your system.

Installation

npx projen install

Deployment

npx projen deploy

Usage

1. Once deployed, test sending messages and subscribing to events in both namespaces:
   • In AWS Console, AppSync ➜ sample-api ➜ Pub/Sub Editor.
   • To send a message:
     1. Select a namespace.
     2. Provide a channel name (e.g., /ch1).
     3. Leave the default JSON payload or provide a custom one.
     4. Click Publish.
   • To subscribe to messages:
     1. Select a namespace.
     2. Provide a channel name (e.g., /ch1) or leave the default (/*) to subscribe to all channels.
     3. Click Subscribe.
2. For the foo namespace:
   • You should see that the messages received by subscribers are transformed.
   • Optionally, to see the logs generated by the Lambda function:
     • In AWS Console, CloudWatch ➜ Log groups ➜ /aws/lambda/sample-function.
3. For the bar namespace:
   • To see the messages stored in the table:
     • In AWS Console, DynamoDB ➜ Tables ➜ sample-table.

Cleanup

npx projen destroy

Application Details

• foo
  • An AppSync namespace with a Lambda data source integration.
  • It uses a Direct handler for all events.
  • Logs onPublish and onSubscribe events, while transforming onPublish messages.
• bar
  • An AppSync namespace with a DynamoDB data source integration.
  • It uses an AppSyncJS handler for all events.
  • Stores onPublish messages and onSubscribe events in a DynamoDB table.

Architecture Diagram