AWS Lambda with Node.js: A Quick Beginner's Guide

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22nd Jun, 2022
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AWS Lambda with Node.js: A Quick Beginner's Guide

While creating an application, every developer puts effort into delivering a fantastic user experience to the users. Your backend code needs to run whenever an event occurs on the application. As a result you need to manage your infrastructure so that it can easily host and execute backend code. It can be done by provisioning and scaling servers, managing system updates whenever available, ensuring security patches are done, and consistently monitoring the performance of the infrastructure.

Creating such applications might be complex. But creating applications without any dependency on the underlying infrastructure would be great. This is why the AWS Lambda was introduced and overcame this challenge for the developers. By the end of this article, you can create a Node.js application using AWS Lambda. To go into detail, you must try the best node course.

But before that, we will deep dive into the basics of AWS, AWS Lambda function, serverless computing, and then step forward to create the application. 

AWS Lambda Prerequisites

Before creating a Node.js application, you must create a setup with proper accounts and installed packages.

  • AWS account – create an account and remember your id and password. 
  • Node.js and npm – install the latest version of Node.js and NPM to have compatible execution of commands. The best full stack developer course duration is not too long. If you get enough time, you can learn easily. 
  • Serverless Framework installed – install your choice of the serverless framework. 

Age of Serverless

Earlier, companies had to manage their server and infrastructure to create even a small application, which came with a huge investment cost. But with, the introduction of cloud computing, where companies rely on cloud providers for a fixed amount of services and resources, including servers, is enough for unexpected spikes in the traffic. This lead to the wastage of server resources when the traffic is expected. To overcome server wastage, the cloud vendors have come up with the idea of auto-scaling models. But this auto-scaling model leads to DDos attack activities that can become more costly. 

With serverless computing, you can avail of the backend services on an as-used basis. You can use any serverless provider to write and deploy the code without relying on the underlying infrastructure. Using the backend services from a serverless provider is a cost-effective solution, as you only have to pay based on the computation. Also, you do not have to worry about reserving and paying for the fixed bandwidth, as it is auto-scaling. Despite the name serverless, it still uses the physical servers that the users are unaware of.

AWS

AWS stands for Amazon Web Services, a cloud-based platform that uses inter-connected web-based services to create applications. It has helped several businesses irrespective of the type and size. With its several pre-built services, you can customize your cloud-based solutions. It lets you choose your choice of server with the pay-per-services option, making it a cost-effective solution for business.

It lets the business run its applications via mobile or desktop. Today, each application is built after considering the great user experience for their users. To achieve that, we want several tasks to run simultaneously. We need to create a back-end code that responds to the code. You can seamlessly manage the infrastructure to host back-end codes. It only requires lots of servers. With the AWS Serverless Cloud Functions, the user can only focus on building the application. 

AWS Lambda Function

You need to code your application in a language supported by Lambda, such as Node.js. It will administrator all the servers, OS, auto-scaling, logging, and monitoring code. It has made it easier for developers to run any type of application. With the AWS lambda function, you can effortlessly run your code without even provisioning or managing several servers. 

AWS Lambda lets you extend other AWS services with custom logic or create your backend services. AWS Lambda automatically runs code for multiple events using Amazon API Gateway. 

So, you must organize your code in Lambda functions. To call the Lambda functions, you need to use the Lambda API. 

AWS Lambda Features

Below are the significant features that have made it widely adopted across the globe. 

  • It lets you control the scaling and responsiveness of your applications. 
  • You can choose container images and workflows to create, test, and deploy your lambda functions. 
  • It comes with code signing ensuring that you have deployed the unaltered code in your lambda functions. 
  • It comes with lambda extensions that allow you to integrate Lambda with other tools for better functionality. 
  • It offers a functioning blueprint (including sample code and config) that will explain you to use the lambda function with other AWS services. 

Advantages and Disadvantages of AWS Lambda Function

Below are the advantages and disadvantages of using the AWS Lambda function. 

Advantages of using AWS Lambda 

  • AWS Lambda function makes it easier for the developers to run and deploy applications, as they do not have to manage and scale servers manually. 
  • No more Virtual Machine are required to run applications. 
  • It is cost-effective, as you only have to pay for the compute actions that include the running of your code. 
  • To know what is going on with your application, you can use the CloudWath to monitor your code performance in real-time. 
  • It scales automatically and is capable of handling thousands of requests per second. 
  • Being stateless, it can be scaled quickly. 

Disadvantages of AWS Lambda 

  • It might not be suitable for small projects, as you might not require it. 
  • Due to its reliability on AWS for the infrastructure, so might not be able to install additional software required by your project. 
  • You can only execute concurrent tasks up to 100 only. 
  • You have to use CloudWatch to write, troubleshoot, and manage the logs.

Lamda App with Node.js

Node.js is one of those languages efficiently supported by the Lambda function. So, in this section, we will see to create an application using Nodejs lambda. Below are the steps to get started with AWS lambda Nodejs. 

Create an AWS Account

For implementing the Lambda function, you must have an AWS account. So create one. All you need is a valid email address, Phone number, and Valid credit card. You can simply go for its free tier plan for beginners without paying anything. Now set up a free account using the below simple steps. 

  • Open the AWS console. 
  • Select “create a free account.” 
  • Provide all the details. 
  • Enter the payment information and verify all the information. 
  • For verification, you will get a four-digit code on your screen. Enter it. 
  • Then, select the free plan. 
  • Now, you are ready to use your free AWS account. 

Setting Up Your Local Development Environment

To start working on a lambda Nodejs application, we are going for the serverless framework. It is a CLI tool written in Node.js. Using this tool, you can quickly write and deploy the lambda functions. You must have Node.js installed to install the serverless framework. But make sure that you have the Node.js version supported by Lambda.

For this article, we are using the Node.js v12.x runtime. So we start with setting the runtime. Also, set your local environment as close to your production environment for better results and application work. 

If you do not already have Node.js installed on your system, then go for the the latest version. Hit the following command on your terminal. Here, we have specified the specific version to install. 

$ nvm install v16.15.0 

If you have another version available and do not want to uninstall that, so make sure to use the above version using the following command. 

$ nvm use 16.15.0 

The next step is to install the serverless framework for your application. Execute the following command with -g specifying the global install. 

$ npm install -g serverless 

Now, check which version of the serverless framework has been installed using the following command. 

$ serverless --version 

Create a Programmatic User on AWS

To use the lambda function in environment other than local, you need to take it to the AWS environment, known as deployment. You will need a programmatic user account so that your Serverless framework can seamlessly access the AWS resources and deploy your functions. You cannot use this user to log in to the AWS console. It will only access the available AWS resources with the help of the API calls using access keys. 

Below are the simple steps to creating a programmatic user. 

  • Go to the AWS console and put the IAM user in the search bar. 

  • Select add user, as shown below. 

  • Fill the lambda-example-cli as the user name, select the programmatic access, and click on Next: permissions. 

  • Select the existing policy directly option and click the Administrator access box to define the permissions of a user, role, or group. 

  • Confirm the changes and then click the create user button.

  • Click the download a CSV file option. It will provide you with access key ID and access key secret. 
  • Now, configure the serverless CLI using the downloaded AWS credentials. 
serverless config credentials --provider aws --key <access_key_id> --secret <access_key_secret> 

Your First Lambda App with Node.js

In this AWA Lambda Nodejs example, you can see a simple hello world application.

$ serverless create --template hello-world //lambda function nodejs 

If the above command runs successfully, you will see two files below. Run the ls command.  

In the above Nodejs lambda example, we have specified the template argument that specifies the choice of template. The serverless CLI has many templates.

AWS Lambda: Handler.js, Event, Context, Callback

Handler.js is the Lambda function with the below code.

'use strict'; 
module.exports.helloWorld = (event, context, callback) => { 
... 

As you can see, the above AWS Lambda node function specified three arguments event, context, and a callback. Let us discuss them in detail. 

Event 

It stores the event data. Different events have different attributes. You need to specify a service that will trigger the Lambda function. 

Context 

It is the argument that we will pass as the runtime parameter to the Lambda function. 

Callback

This argument will return the responses to the caller. 

Serverless.yml 

It is a file containing your API definition and other necessary resources required by your application to perform as expected.

We will make some changes to serverless.yml and change the runtime property to nodejs8.10. Then, add a new property called region so you can deploy your app to your specific region. The region property is optional, and if you do not specify it specifically, it will use the default us-east-1.

As you can see, without setting the region, it is showing us-east-1 by default. 

Below is the content of the serverless.yml file. You can see it using the “cat” command from terminal. 

You can add the region as shown below in the serverless.yml file. 

service: serverless-hello-world 
# The `provider` block defines where your service will be deployed 
provider: 
 name: aws 
 runtime: nodejs8.10 
 region: eu-west-1 
.... 
Deploy the app 
Execute the command from your console to deploy the AWS lambda node js. 
$ serverless deploy 
You will see the below output. 
... 
api keys: 
None 
endpoints: 
GET - https://ss7n639ye3.execute-api.eu-west-1.amazonaws.com/dev/hello-world 
functions: 
helloWorld: serverless-hello-world-dev-helloWorld 
… 

In the above node lambda example, you can see the endpoint. You can open this link from your browser to see the output. 

Logging AWS Lambda Function

To understand how your application is performing in production environment, you can check the logs. It is also helpful for troubleshooting your application. You can simply use services for logging purposes, such as Retrace, AWS Cloudwatch, etc., that can work with Lambda functions well. If you do not want to use other Amazon services, you can also log an event from your code using the console.log. 

console.log('An error occurred') 

You can opt for a knowledgeHut’s best node course to learn detailed working. 

Conclusion

Creating Node.js applications using Lambda functions is easy. Whether you are a beginner or an experienced person, all you need is to learn Node.js and how to work around the AWS console. You can get this knowledge online. In this article, we have explained an easy way of creating Lamba Node.js applications.

Today is the time of serverless applications as it does not require you to indulge in the technical part of managing infrastructure and resources. You need to opt for the third party that will do it for you.

Frequently Asked Questions (FAQs)

How can I run Node.js on AWS Lambda?

Use the handler to write the AWS Lambda function in Node.js. The handler in Node.js combines the file name and export function. For Example, we are using the file data.js, and the export function is lambda handler so that the handler will be data.lambdahandler 

For example-

exports.lambdahandler = function(event, context, callback) { //code goes here} 

Can I use Node.js with AWS?

Yes, you can use Node.js with AWS by using any following methods. 

  • You can use the Amazon Machine Image (AMI) to create an Amazon EC2 instance with that AMI.
  • You can simply create an Amazon EC2 instance and install then use Node.js by installing on that instance. 
  • Using AWS Lambda function to create a serverless environment and run your Node.js code as a Lambda function, as explained in this article. 
  • You can also use the AWS Elastic Beanstalk to run your Node.js application. 
  • Use the AWS OpsWorks to create a Node.js application server.

What is the reason for picking node.js for Lambda functions?

Nodejs is one of the languages that is seamlessly supported by the AWS Lambda function. The supported version of Node.js is v6.10 and v8.10. Lambda supports the Node.js runtimes. 

What do you mean by the Lambda function in Node.js?

Lambda offers a runtime for Node.js to run your code to process the available events.

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Aashiya Mittal

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Aashiya has worked as a freelancer for multiple online platforms and clients across the globe. She has almost 4 years of experience in content creation and is known to deliver quality content. She is versed in SEO and relies heavily on her research capabilities.

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