AWS API gateway + AWS Lambda + NodeJS REST API development

from— pexels.com

API Gateway is gateway service of AWS cloud platform to access backed services like EC2 and Lambda as HTTP endpoints.
API gateway provides

— Security
— Monitoring
— Deployment Life Cycle
— Custom Request and Response
— Request Validation

features to maintain and monitor apis.

AWS Lambda is serverless service of AWS cloud platform to develop serverless solutions with

• Scalability
• Security
• Monitoring
• Version management

Lambda support following programming languages.

• Python
• Javascript
• Java
• GoLang
• C#
• Powershell

Pre-requisite — An AWS account — https://portal.aws.amazon.com/billing/signup#/start

Create a Lambda function ⚡️ ⚡️

STEP 1 — Goto — Lambda home — https://us-east-2.console.aws.amazon.com/lambda/home?region=us-east-2#/functions

STEP 2 — Click on create function

STEP 3 — Select Author from scratch and fill the given form.

Name — myLambda

Runtime — Node.JS8.10

Role — Create new role from one or more templates

Role Name — myLambdaRole

Policy Template — Amazon S3 object read only permission

Click to “Create function” button.

Congratulations your lambda function got created 👏 👏

myLambda function created

Create an API 🔌

STEP 1 — Goto — API Gateway home — https://us-east-2.console.aws.amazon.com/apigateway/home?region=us-east-2#/apis

crate-api

STEP 2 — Click CreateAPI button and insert required details

New API creation

Api name — myLambdaAPI

Description — A basic api creation

Endpoint Type — Regional

and click “CreateAPI” button.

Congratulations your new AWS api got created 👏 👏

API dashboard — https://us-east-2.console.aws.amazon.com/apigateway/home?region=us-east-2#/apis

myLambda API created

API and Lambda Function Linking 🔗 🔗

STEP 1 — Click on api(myLambdaApi) => click on action drop down => Click Create Method

STEP 2 — select ANY from drop down and click ☑️ button.

Create Method

STEP 3 — Select Radio button “Lambda Function” and enter lambda function name “myLambda” and click save button

STEP 4 — click OK to confirm Lambda service execution permission to API gateway.

STEP 5 — Click on Test Icon ⚡️

AWS Gateway Method setup

STEP 6 — select GET method from dropdown and click Test button.

AWS api gateway test screen

Expected output

{
  "statusCode": 200,
  "body": "\"Hello from Lambda!\""
}

AWS lambda testing screen.

Congratulations AWS api gateway and Lambda function linking done successfully. 👏 👏

Deploy AWS Gateway API 🚀 🚀 🚀

STEP 1 — Goto API dashboard — API dashboard — https://us-east-2.console.aws.amazon.com/apigateway/home?region=us-east-2#/apis and click myLambdaAPI

api dashboard

STEP 2 — Click Actions drop down => click Deploy API

Opened Action Dropdown

STEP 3 — select [new State]

select new stage

Enter stage details and click Deploy button.

STEP 4 — Goto to stages and click “Invoke URL”

Expected output

lambda api response

Congratulations you public api is ready 🔥 🔥

References:

• https://docs.aws.amazon.com/lambda/latest/dg/getting-started.html
• https://docs.aws.amazon.com/apigateway/latest/developerguide/welcome.html