Building serverless applications with AWS Lambda

Posted on by Panther

Serverless computing has changed the way developers approach application development and infrastructure management. AWS Lambda is a popular serverless computing platform that allows you to run your code without worrying about managing servers or infrastructure. In this tutorial, we will walk you through the process of building serverless applications with AWS Lambda.

Prerequisites

Before starting this tutorial, make sure you have the following:

  • An AWS account
  • A code editor
  • Basic knowledge of programming

Step 1: Create an AWS Lambda function

The first step in building a serverless application with AWS Lambda is to create a Lambda function. A Lambda function is the code that you want to run in response to an event. Here’s how you can create a Lambda function in the AWS console:

  1. Open the AWS Management Console and navigate to the Lambda service.

  2. Click on the “Create Function” button.

  3. Choose the “Author from scratch” option.

  4. Provide a name for your function.

  5. Choose a runtime environment. AWS Lambda supports multiple programming languages, including Node.js, Python, Java, and more.

  6. Specify the role that AWS Lambda will use to execute your function. You can either choose an existing role or create a new one.

  7. Click on the “Create Function” button.

Once you’ve created your Lambda function, you can start writing the code.

Step 2: Write your Lambda function code

To write your Lambda function code, you need to choose the programming language that you want to use. AWS Lambda supports multiple programming languages, including Node.js, Python, Java, and more.

For this tutorial, we will write a simple Node.js function that returns “Hello World” when invoked. Here’s the code:

exports.handler = async function(event) {
  return "Hello World";
};

Save this code in a file named index.js. Once you have your code ready, you can upload it to AWS Lambda.

Step 3: Upload your Lambda function code

To upload your Lambda function code, follow these steps:

  1. Open the AWS Lambda console and select your function.

  2. Click on the “Code” tab.

  3. Click on the “Upload from” button and choose “.zip file”.

  4. Upload your index.js file.

  5. Click on the “Save” button.

Step 4: Test your Lambda function

Once you’ve uploaded your code, you should test your Lambda function to make sure it’s working correctly. Here’s how you can test your Lambda function:

  1. Open the AWS Lambda console and select your function.

  2. Click on the “Test” tab.

  3. Click on the “Test” button and provide input data (if required).

  4. Click on the “Create” button.

  5. You should see the output of your function.

If you see the output “Hello World”, your Lambda function is working correctly.

Step 5: Add an API Gateway trigger

API Gateway is a fully managed service that makes it easy to create, publish, maintain, monitor, and secure APIs. You can use API Gateway to create RESTful APIs that integrate with AWS Lambda.

To add an API Gateway trigger to your AWS Lambda function, follow these steps:

  1. Open the AWS Lambda console and select your function.

  2. Click on the “Add trigger” button.

  3. Choose the “API Gateway” option.

  4. Select the “REST API” option.

  5. Choose the security settings for your API.

  6. Click on the “Add” button.

Once you’ve added the API Gateway trigger to your Lambda function, you can test your API.

Step 6: Test your API

To test your API, follow these steps:

  1. Open the AWS API Gateway console.

  2. Click on the “APIs” option.

  3. Click on the “Create API” button.

  4. Choose the “REST API” option.

  5. Choose the “New API” option.

  6. Provide a name for your API.

  7. Click on the “Create API” button.

  8. Click on the “Create Method” option.

  9. Choose the HTTP method that you want to use, such as GET.

  10. Select the Lambda function that you want to use as the backend.

  11. Click on the “Save” button.

  12. Click on the “Test” button.

  13. Provide input data (if required).

  14. Click on the “Test” button.

  15. You should see the output of your function.

If you see the output “Hello World”, your API is working correctly.

Step 7: Deploy your API

Once you’ve tested your API, you should deploy it to make it available to your users. Here’s how you can deploy your API:

  1. Open the AWS API Gateway console.

  2. Select your API.

  3. Click on the “Actions” button.

  4. Select the “Deploy API” option.

  5. Choose the deployment stage that you want to use.

  6. Click on the “Deploy” button.

Once your API is deployed, you can make requests to it using the API URL.

Conclusion

In this tutorial, we’ve walked you through the process of building serverless applications with AWS Lambda. We’ve shown you how to create a Lambda function, upload your code, add an API Gateway trigger, test your API, and deploy your API. With AWS Lambda, you can build serverless applications quickly and easily, without worrying about infrastructure management. We hope this tutorial has been helpful to you, and that you’re excited to start building your own serverless applications with AWS Lambda.

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