Lambda

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.

My First Contribution to Serverless Application Repository

Recently, I have created a simple API to retrieve AWS services by it’s regions. And I decide to make it a Serverless Application and now it is generally available to be used by anyone. AWS SAR : Github: https://github.com/pubudusj/serverless-aws-services How it works Once you deploy the application using SAM locally or using SAR, there is a API gateway url in the output section. You can directly access the url, which will output JSON response which is in similar structure as below:

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.