Created API for Invoice Portal using AWS Lambda function and API Gateway

At first I decided to use MongoDB Atlas Data API for my Invoice Portal App to read and write data from MongoDB database. But during querying the Mongo Data API, it gave an CORS error.

So, MongoDB Data API only supports server apps and not browser app .In order to use it you have to implement another API in front of it to access it.

I wanted to learn and use AWS services ,so I thought of using AWS Lambda and API Gateway to create the APIs. 

Create a MockAPI using AWS Lambda function and API Gateway and test it in Postman.

AWS Lambda

1.     Created createInvoice function by connecting it to MongoDB database and using InsertOne                     function of MongoDB, to add data to the collection

        const result = await db.collection("Invoices").insertOne(JSON.parse(event.body));

2.    Created getSingleInvoice function and used find function of MongoDB, to find the requested                 Invoice based on path parameter InvoiceID in the API route.

        

         //Get the parameter invoiceID from the event to find the invoice from the DB

         var invoiceID = event.pathParameters.invoiceID;

     

        const invoice = await db.collection("Invoices").find({ "_id": new ObjectID(invoiceID)                              }).toArray();

3.    Created getAllInvoices function ,to get all the invoices from the DB

        

        const invoice = await db.collection("Invoices").find({}).toArray();

AWS API Gateway

1.    Create API

2.    Select HTTP API which has CORS support in it and Build it

3.    Add API Name and  in Add Integrations ,add Lambda functions that you created

4.    Configure routes select HTTP route method and route path based on what your function will be               doing

5.    Configure Access-Control-Allow-Origin to * i.e. ALL

API implementation code:

Git Back End Invoice Portal App