Serverless API with AWS Lambda, DynamoDB, and API Gateway for Data Management

Overview

This Document guides you through the process of setting up an Amazon API Gateway, a Lambda function, and a DynamoDB table. The API supports various DynamoDB operations and includes testing methods. The Lambda function is integrated with the API Gateway, allowing you to perform CRUD operations on a DynamoDB table.

Architecture

Setup

Create Lambda IAM Role

1. Open the roles page in the IAM console.
2. Choose Create role.
3. Create a role named lambda-apigateway-role with permissions for DynamoDB and CloudWatch Logs.

   {
       "Version": "2012-10-17",
       "Statement": [
           {
               "Sid": "Stmt1428341300017",
               "Action": [
                   "dynamodb:DeleteItem",
                   "dynamodb:GetItem",
                   "dynamodb:PutItem",
                   "dynamodb:Query",
                   "dynamodb:Scan",
                   "dynamodb:UpdateItem"
               ],
               "Effect": "Allow",
               "Resource": "*"
           },
           {
               "Sid": "",
               "Resource": "*",
               "Action": [
                   "logs:CreateLogGroup",
                   "logs:CreateLogStream",
                   "logs:PutLogEvents"
               ],
               "Effect": "Allow"
           }
       ]
   }

Create Lambda Function

1. Click "Create function" in AWS Lambda Console.
2. Select "Author from scratch," name it LambdaFunctionOverHttps, choose Python 3.7 as Runtime.
3. Under Permissions, select "Use an existing role," and choose the lambda-apigateway-role from the drop-down.
4. Click "Create function."
5. Replace the code with the provided Python code snippet and click "Save."

Test Lambda Function

1. Configure a test event with the following JSON:

   {
       "operation": "echo",
       "payload": {
           "somekey1": "somevalue1",
           "somekey2": "somevalue2"
       }
   }

2. Click "Test" to execute the test event.

Create DynamoDB Table

1. Open the DynamoDB console.
2. Choose "Create table."
3. Create a table named lambda-apigateway with the primary key as id (string).
4. Click "Create."

Create API

1. Go to the API Gateway console.
2. Click "Create API" and select "Build" for REST API.
3. Name the API as DynamoDBOperations and click "Create API."
4. Click "Actions," then click "Create Resource."
5. Input "DynamoDBManager" as the Resource Name and click "Create Resource."
6. Create a POST Method for the API with the "/dynamodbmanager" resource selected.

Deploy the API

1. Click "Actions" and select "Deploy API."
2. Choose "[New Stage]" for "Deployment stage" and name the stage as "Prod."
3. Click "Deploy."

Run the Solution

1. Obtain the API endpoint URL from the "Stages" screen.
2. Use Postman to execute the API using a sample JSON payload for the create operation.
3. Execute the provided JSON for DynamoDB create operation through Postman using the generated API Invoke URL.

   {
       "operation": "create",
       "tableName": "lambda-apigateway",
       "payload": {
           "Item": {
               "id": "1234ABCD",
               "number": 5
           }
       }
   }

4. Verify the item in DynamoDB console.

Cleanup

1. Delete the DynamoDB table from the DynamoDB console.
2. Delete the Lambda function from the Lambda console.
3. Delete the API from the API Gateway console.

Congratulations!

🎉 You have successfully created a serverless API with AWS Lambda, API Gateway, and DynamoDB! 🚀