Serverless

AWS Step Functions — Are Active Executions Affected When Your State Machine Gets Updated?

Intro AWS Step Functions is a Serverless orchestration service that helps to build a workflow with various steps that connect different AWS services. These steps are defined in State Machine, which will be implemented in Amazon States Language (ASL). There are two types of workflows in Step Functions: Express flow Standard flow Among many differences, Express flow can only run up to five minutes and Standard flow can run up to one year.

Simple Leave Management System with AWS Serverless

Intro In this project, I will discuss how you can build a simple leave apply/approval system using AWS Serverless services. These are the main functionalities of this implementation. Apply for a leave Confirmation for leave application. Send notification to the approver regarding new leave request. Send reminder notification to the approver. Send notification upon approval/rejection. And below services/functionalities are in use in this project: Step functions SDK integrations for SES, DynamoDB Step functions Parallel processing Step functions wait for callback pattern Lambda function URLs DynamoDB streams with filtering AWS CDK with TypeScript as IAC Architecture State Machine How it works Create a leave request CreateLeave Lambda function accepts leave requester’s email, leave approver’s email, leave dates and reason and is responsible to validate and save it to the DyanmoDB table.

Manage webhooks at scale with AWS Serverless

Webhooks are still a preferred choice of many organizations to communicate with 3rd party services. Since webhook calls are event-driven, building a webhook management system with Serverless is a great choice. In this post, I am going to discuss how to build such a webhook management system with AWS Serverless. In an Application Tracking Systems (ATS), whenever a candidate related event occurs (ex: candidate created, applied for a job, candidate state changed, etc), it might need to call to a registered webhook.

How to create a simple OTP service with AWS Serverless services

Intro This post describes how to implement a simple One Time Password (OTP) system with AWS Serverless services which can be used as a part of two step verification. Below tools and technologies used to build this application. AWS Lambda API Gateway DynamoDB Simple Email Service - SES Amplify Web Hosting VueJS for frontend Deploy with AWS SAM Architecture Image: Architecture How it works In this scenario, I used a login form, which is developed with VueJS and hosted using Amplify static web hosting.

How I created a Photo Booth with AWS Serverless

Intro This is how I built a photo booth application with AWS Serverless services. Once user capture an image and provide an email, background of the image is removed and new background applied and watermark with timestamp will be added. Then the image will be emailed to the given email address. Below tools and technologies are used to built this. Backend: AWS Lambda with runtime Node.js Step Function S3 SES remove.

How I created a simple activity logger with AWS Serverless to record nuisance activities of my neighbor

NOTE: This post is originally published at dev.to Intro This is how I created a simple activity logger with AWS API Gateway direct integrations with DynamoDB to record some nuisance activities of one of the neighbors. There are few activities he does which annoy us, such as door slam, punch to the wall, and walking with klomps which make a heavy sound. He is not corporating, so before going for further actions, I wanted to keep track of when he does those activities.

How I created a 'physical' alarm to warn me when my servers are down

NOTE: This post is originally published at dev.to This post contains a weekend project I worked on to create an alarm when my AWS EC2 servers are down. Tools and technologies used: AWS Lambda, EventBridge, Greengrass, Raspberry Pi, Active Buzzer and LED light (as the alarm), GPIO, etc. Architecture: How it works: When an EC2 is stopped or terminated, EventBridge will capture the event. EventBrige will trigger the Lambda function (PublishToIotCloud) which publish a message to IOT cloud with the topic ‘alarm’.

How I created a door bell with AWS Serverless

NOTE: This post is originally published at dev.to Intro Recently, there was a hackathon at my work place, Wonderkind, and with one of my colleagues, I created a intelligent door bell with AWS Serverless services + a raspberry pi. Whenever someone clicks on the button of the ‘door bell’, it will capture a image and check through a Amazon Rekognition faces collection to see if the faces on the image are already indexed.

Whitelisting Lambda IP

Recently, one of my friend/client came up with the scenario below. Scenario: There is a lambda function, which calls to a external API and fetch some data. This external API only accepts incoming requests only from pre-configured whitelisted IPs. As per today, AWS doesnt’ support elastic IPs for Lambda. However, there is a simple work around. Solution: Simple solution is, to create the lambda function within a VPC and make the 3rd party API to be accessible via a NAT gateway.

Understanding Lambda Concurrency

Lambda by nature is highly scalable. However there ares some limitations you need to consider when there are lot of Lambda functions run simultaneously. Please note: This will not applicable for all the scenarios, but for a system with a high throughput. Account Level Concurrent Execution Limit As at now, Lambda has a soft limit of 1000 concurrent executions per region. Which means, at any given moment, sum of lambda executions running belongs to all of your lambda functions in a single region must be less than 1000.