typescript

The Simple GraphQL Service

This is an example CDK stack to deploy The Simple GraphQL Service inspired by Thorsten Hoeger's contributions to the CDK AppSync Module example

An advanced version of this pattern was talked about by Heitor Lessa at re:Invent 2019 as "The Cherry Pick".

• Youtube Recording
• Static Slides

This is the most basic of AppSync implementations and would have to be hardened before production use. e.g. cognito user pools configured

Note, never print your API Key to the logs in a production system. This was added to make learning AppSync and GraphQL easier. If you want to use this pattern in a production system remove the two cloudformation outputs

Testing

1. After CDK Deploy, capture outputs from the log.

TheSimpleGraphqlServiceStack: deploying...
TheSimpleGraphqlServiceStack: creating CloudFormation changeset...

   TheSimpleGraphqlServiceStack

Outputs:
TheSimpleGraphqlServiceStack.APIKey = <API Key>
TheSimpleGraphqlServiceStack.Endpoint = https://<endpoint URL>.appsync-api.us-east-1.amazonaws.com/graphql

2. Setup Postman as outlined in Postman's Using GraphQL Instructions

3. Set POST request URL, x-api-key and Content-Type

• x-api-key = 'your API Key'
• Content-Type = application/graphql

4. Execute Mutations and Queries to exercice resolvers to dynamo and Lambda datasources

// Inserts to Dynamo
mutation add {
  addCustomer(customer: { name: "CDKPatterns"}) {
    id
    name
  }
}

// Queries the Dynamo DB
query getCustomers {
  getCustomers{id name}
}

// Executes the Lambda
query getLoyalty {
  getLoyaltyLevel { level }
}

Useful commands

• npm run build compile typescript to js
• npm run watch watch for changes and compile
• npm run test perform the jest unit tests
• npm run 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