AWS Lambda lets you host your code/function without worrying about server or scaling. AWS Lambda is Serverless solution, while using any AWS services, it is easy to point them to lambda function, for an e.g. 1. scheduling lambda function to run on specific timing interval using AWS Cloudwatch rules 2. any image is uploaded to AWS S3, lambda function can create thumbnail for it. 3. creating backup of EC2 instance at timely manner using lambda function and many more. But to use these functionalities within AWS, you don’t need to create REST API endpoint. You can directly integrate AWS Lambda with other services. What if you want to create webhook URL of your lambda function, or you have created API using lambda function and you need API endpoint to point from mobile or web app. In that case, we can use AWS API Gateway to create API endpoint which will point to lambda function.
We will also see how to secure API endpoint from unnecessary traffic using Authorization Header, or you can create open API as per your use case and here, open API means
Let’s get started
Pre requisite
AWS Account
AWS access to create AWS Lambda function and AWS API Gateway
1. Log in to AWS Account
Go to Services and select Lambdaunder Compute section
Check and select Region from right top panel
Click on Create Function
Select Author from scratch
Type function name, and select Python 3.6 or 3.8 version
In permission, Create a new role with basic Lambda permissions
Keep other settings as it is and click on Create function
2. Sample Code
Here, we are going to deploy sample python code will prints JSON as Hello World from IdenticalCloud! , Mainly because our main focus on this tutorial is how to integrate API Gateway with AWS Lambda
Copy below code in lambda_function.py file
import json
def lambda_handler(event, context):
# TODO implement
return {
'statusCode': 200,
'body': json.dumps('Hello World from IdenticalCloud!')
}
You can change body message as per your choice
3. Add Trigger
At left top panel, there’s an option to add a trigger, Click on Add Trigger
In Trigger configuration, select API Gateway
at API, select Create an API
Select REST API
Now, comes security part, In this tutorial, we will see how to create Open API, as well as how to create authentication protected API
For first case, select Open
Choose API name and Deployment stage as per your requirement
and Click on Add
aws-lambda-apigateway
Now, as you can see screenshot attached, here you will get API endpoint which is accessible through internet. Try and run that URL in your browser and you will result as Body
To create authentication protected API
Repeat above described steps and at Security, select API Key
Choose API name and Deployment stage as per your requirement
and Click on Add
Now, at this point if you copy and paste API Gateway URL, you will receive the following error
{"message":"Forbidden"}
You need authentication header to confirm that you are authrozied to use this URL
For that,
Go to AWS Services –> select API Gateway
Select your API Gateway name
In left panel. locate API Keys
Select given API Key, and click on Show button
Copy API Key and save it in secure place
Now, you can try running API Gateway URL with this authorization key header
