Creating microservice in simple steps using AWS API Gateway, Lambda & DynamoDB

Microservices have revolutionized software development by breaking down complex applications into smaller, independent services that can be deployed and scaled separately. In this article, we’ll walk through creating a microservice using AWS API Gateway, Lambda, Python, and DynamoDB.

Step 1: Create a DynamoDB table

First, we need to create a DynamoDB table to store our data. We’ll use this table to store information about our service. To create a DynamoDB table, go to the AWS Management Console and select DynamoDB. Click on Create table and give it a name, such as “MyServiceTable”. Set the partition key to “myservice_id” and click on Create.

Step 2: Create a Lambda function

Next, we’ll create a Lambda function to handle requests to our microservice. Go to the AWS Management Console and select Lambda. Click on Create function and choose “Author from scratch”. Give your function a name, such as “MyServiceHandler”. Set the runtime to “Python 3.8”. Under “Permissions”, choose “Create a new role with basic Lambda permissions”. Click on Create function.

Now, we need to write the code for our Lambda function. Here’s an example function that will retrieve information about a service from our DynamoDB table:

import json
import boto3
dynamo = boto3.resource('dynamodb')
table = dynamo.Table('MyServiceTable')
def lambda_handler(event, context):
    service_id = event['pathParameters']['myservice_id']
    response = table.get_item(Key={'service_id': myservice_id})
    item = response.get('Item')
    if not item:
        return {
            'statusCode': 404,
            'body': json.dumps({'error': 'Service not found'})
        }
    return {
        'statusCode': 200,
        'body': json.dumps(item)
    }

This function will receive a request with a myservice_id in the path parameter. It will use this ID to retrieve the corresponding service from our DynamoDB table. If the service does not exist, the function will return a 404 Not Found error. Otherwise, it will return a 200 OK response with the service information.

Step 3: Create an API Gateway endpoint

Now, we’ll create an API Gateway endpoint to handle requests to our microservice. Go to the AWS Management Console and select API Gateway. Click on Create API and choose “REST API”. Give your API a name, such as “MyServiceAPI”. Under “Security”, choose “Open” and click on Create API.

Next, we need to create a resource and method for our endpoint. Click on Create Resource and give it a name, such as “MyService”. Click on Create Method and choose “GET”. Select our Lambda function as the integration type and click on Save.

Now, we need to deploy our API to a stage. Click on Actions and choose Deploy API. Give your deployment a name, such as “Production”. Choose a deployment stage, such as “prod”, and click on Deploy.

Step 4: Test our microservice

Now, we can test our microservice by sending a request to our API Gateway endpoint. The URL of our endpoint should be displayed in the Stages section of our API Gateway dashboard.

For example, if our endpoint URL is “https://api.example.com/prod/myservice/{myservice_id}", we can send a GET request to “https://api.example.com/prod/myservice/1234" to retrieve information about the service with ID 1234.

Conclusion

In this article, we’ve walked through creating a microservice using AWS API Gateway, Lambda, Python, and DynamoDB. We’ve created a DynamoDB table to store our data, a Lambda function to handle requests to our microservice, and an API Gateway endpoint to route to our Lambda function.

To know more about AWS Microservices, refer to the below link

https://aws.amazon.com/microservices/