Since my app is of a food tracking system, I eventually need to implement an Android app to show an overview of what is inside the fridge inventory.

I am planning for a HTTP API for (perhaps) an Android App to access. The request flow will be like this.

• Android app → HTTP Request → AWS API Gateway → AWS Lambda → AWS DynamoDB

I will try out AWS API Gateway today to retrieve contents in the AWS DynamoDB database.

(1) Create Lambda to be invoked by API Gateway.

Go to Lambda console

• Function > Create function
• Function name: CypressPsocApiLambda

After creating the lambda go to IAM console

• Access management > Roles > Permissions > (Click on the function name) 
• Attach policy: AmazonDynamoDBFullAccess

(2) Create API Gateway and integrate it to Lambda

Navigate to the API Gateway service console, and choose Create API. In API name, type CommentsApi and type a short description. Finally, choose Create API.

• HTTP API > Build
• API name: CypressPsocApi
• Stage name (leave as default)

Create a route

• GET request: /retrieve

Create and attach and integration

• Integration with: Lambda function > Choose “CypressPsocApiLambda”

(3) Edit Lambda to parse DynamoDB items

I used the document client to scan for the table name. This retrieves all the items without any filters. Perhaps I'll add a filter parameter in if I need it in the future part of this project.

And now, I can go to the /retrieve page and I see all the test entry in my database.

For next time, I want to do up the android app and also the RFID portion of the PSoC device.