DEV Community: Ritul Singh

Schedule Events in EventBridge with Lambda

Ritul Singh — Wed, 18 Dec 2024 10:23:20 +0000

In this blog post, we'll explore how to schedule events using AWS EventBridge Scheduler and AWS Lambda. This method is efficient and scalable, ensuring your application can handle multiple scheduled events without creating a mess of individual EventBridge rules. Let's dive in!

What is AWS EventBridge?

AWS EventBridge is a serverless event bus service that makes it easy to connect applications using data from your own applications, integrated Software-as-a-Service (SaaS) applications, and AWS services. EventBridge delivers a stream of real-time data from event sources and routes that data to targets like AWS Lambda, Amazon SNS, and more.

What is AWS Lambda?

AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. You can trigger Lambda functions directly from other AWS services, such as S3, DynamoDB, or EventBridge, and scale automatically from a few requests per day to thousands per second.

Prerequisites

Before we start, make sure you have the following:

An AWS account
Basic knowledge of Node.js
AWS CLI configured on your machine

Step 1: Setting Up Your AWS Environment

Creating an IAM Role

Firstly, we need to create an IAM role that will allow AWS EventBridge Scheduler to invoke your Lambda function.

Go to the IAM Console: Navigate to the IAM console, choose Roles from the left navigation pane, and click Create role.
Select Trusted Entity: Choose AWS service, select Lambda, and click Next: Permissions.
Attach Policies: Attach the following managed policies:
- AWSLambdaBasicExecutionRole: Provides basic Lambda execution permissions.
- AmazonEventBridgeSchedulerFullAccess: Allows EventBridge Scheduler to manage schedules.
Review and Create: Provide a name for the role, e.g., LambdaExecutionRole, review the settings, and click Create role.
Update Trust Relationship: After the role is created, go to the role details page. Under the Trust relationships tab, click Edit trust relationship. Update the trust policy to include scheduler.amazonaws.com service:

   {
     "Version": "2012-10-17",
     "Statement": [
       {
         "Effect": "Allow",
         "Principal": {
           "Service": "lambda.amazonaws.com"
         },
         "Action": "sts:AssumeRole"
       },
       {
         "Effect": "Allow",
         "Principal": {
           "Service": "scheduler.amazonaws.com"
         },
         "Action": "sts:AssumeRole"
       }
     ]
   }

Step 2: Creating the Lambda Function

We'll create a Lambda function that will process the scheduled events.

Go to the Lambda Console: Navigate to the Lambda console, click Create function, and choose Author from scratch.
Configure the Lambda Function: Set the function name to processScheduledEvent, select Node.js 16.x as the runtime, and use the existing role you created earlier (LambdaExecutionRole). Click Create function.
Add Function Code: Replace the default code with your logic to process the event. For instance, you might log the event details or perform specific actions based on the event data:

   exports.handler = async (event) => {
     const eventDetails = event;

     // Your logic to process the event
     console.log("Processing scheduled event:", eventDetails);

     // Example: Process event
     // processEvent(eventDetails);

     return {
       statusCode: 200,
       body: JSON.stringify('Event processed successfully'),
     };
   };

Deploy the Function: Click Deploy to save the changes.

Step 3: Scheduling the Event

Now, let's write the code to schedule an event using AWS EventBridge Scheduler.

First, install the necessary AWS SDK modules:

npm install @aws-sdk/client-scheduler @aws-sdk/client-lambda

Here’s a summary of the steps to implement the scheduling function:

Extract Event Details

Extract the event details from your application's input. Here is an example:

const eventDetails = {
  name: "TEST-EVENT-01",
  userId: "USER123",
  eventId: "EVENT-001",
  eventTime: '2024-12-17T18:05:00+05:30' // IST time in ISO format
};

Convert IST to UTC

Convert the scheduled time from IST (Indian Standard Time) to UTC (Coordinated Universal Time).

const istTime = new Date(eventDetails.eventTime); // IST time
const utcTime = new Date(istTime.getTime() - 5.5 * 60 * 60 * 1000); // Convert to UTC

Format the UTC Time String

Ensure the UTC time string is in the correct format required by EventBridge Scheduler (yyyy-MM-ddTHH:mm:ssZ).

const utcString = utcTime.toISOString().split('.')[0] + 'Z';

Create an EventBridge Schedule

Create an EventBridge schedule using the AWS SDK, specifying the Lambda function ARN as the target and including the event details as input.

const { SchedulerClient, CreateScheduleCommand } = require("@aws-sdk/client-scheduler");
const schedulerClient = new SchedulerClient({ region: "your-region" });

const createScheduleEventRequest = async (req, res) => {
  try {
    const scheduleParams = {
      Name: `schedule_event_${eventDetails.eventId}`,
      ScheduleExpression: `at(${utcString})`,
      Target: {
        Arn: 'arn:aws:lambda:your-region:your-account-id:function:processScheduledEvent', // Replace with your Lambda function ARN
        RoleArn: 'arn:aws:iam::your-account-id:role/LambdaExecutionRole', // Replace with your Role ARN
        Input: JSON.stringify(eventDetails)
      },
      FlexibleTimeWindow: { Mode: 'OFF' },
      State: 'ENABLED',
    };

    const scheduleResult = await schedulerClient.send(new CreateScheduleCommand(scheduleParams));
    console.log("EventBridge schedule created:", scheduleResult);

    return res.status(200).json({
      success: true,
      message: "Scheduled event created successfully",
    });
  } catch (error) {
    console.error("Error creating scheduled event:", error);
    return res.status(500).json({
      success: false,
      message: "Failed to create scheduled event",
      error: error.message,
    });
  }
};

module.exports = { createScheduleEventRequest };

Conclusion

In this blog post, we walked through the process of setting up a scheduled event using AWS EventBridge Scheduler and Lambda. This approach ensures that our application can handle multiple scheduled events efficiently and scalably. With the power of AWS, you can build robust features that enhance user experience and streamline operations.

Happy coding!

Know About HTTP Response Status Codes

Ritul Singh — Sat, 31 Dec 2022 10:31:45 +0000

HTTP response status codes are 3-digit numbers that are used to indicate the status of a request made to a web server. They are returned by the server in response to an HTTP request and provide information about the result of the request.

Here are some common HTTP response status codes and their meanings:

200 OK: This status code indicates that the request was successful and the requested resource was returned.

301 Moved Permanently: This status code indicates that the requested resource has been permanently moved to a new URL. The server returns this code along with the new URL in the response header.

302 Found: This status code indicates that the requested resource has been temporarily moved to a new URL. The server returns this code along with the new URL in the response header.

404 Not Found: This status code indicates that the server could not find the requested resource.

500 Internal Server Error: This status code indicates that there was an error on the server while processing the request.

There are many other HTTP response status codes, each with its own specific meaning. Some of these codes are used more commonly than others, but it's important to be aware of all of them to understand the full range of responses that a server can send.

In addition to the standard HTTP response status codes, some servers may also return custom status codes to provide more information about the result of a request. These custom codes should be used in conjunction with the standard status codes to provide a complete picture of the request's outcome.

My First Hacktoberfest — Experiences of Contributing to Open Source

Ritul Singh — Tue, 03 Nov 2020 17:18:18 +0000

Contributing to Open Source and projects can seem like a daunting process. Your favorite search engine will return a ton of results on guides and repositories to get started. But many times, your search does not yield the result you want, you still do not know how to contribute to Open Source even after reading multiple blog posts. The impeding reputation of certain projects and a harsh undertone does not help either and might complicate matters even further.

I have been there myself. I trawled through pages to find great Open Source repositories to contribute to, only to notice that I did not know how to start.

Frustrated and a little disappointed, I started focusing on other projects instead.

But it all changed when I saw a fellow employee’s Hacktoberfest sticker on their laptop. I was intrigued — was this a remnant of yet another Hackathon?

Hacktoberfest turned out to be very different.

So what is a Hacktoberfest exactly?

Hint: it doesn’t have to do with either beer or hacking or the Oktoberfest (which actually takes place in September, duh!).

Hacktoberfest is a month-long celebration of contributing to Open Source, running from 1st October to 31st October. It was initiated by DigitalOcean in collaboration with GitHub. During the month of October, you are encouraged to contribute and make pull requests to your favorite repositories on GitHub. If you manage to make four in total, you are eligible to receive a swanky T-Shirt.

What can we take away from this?

I would advise you to free yourself from the assumption, that you need to contribute perfect and well-rounded code the first time. Your first contribution does not have to be ground-breaking (or even be code to be precise).

Conclusion

If you have the experience of contributing to open source, please share it in the comments. Happy Coding!

My Top 10 Visual Studio Code Extensions for Python in 2020

Ritul Singh — Fri, 30 Oct 2020 09:50:45 +0000

1.Python extension for Visual Studio Code

by Microsoft

First and foremost - the Python plugin for VS Code. Out of the box, there is no support for Python in the VS Code, but when you open a Python file, VS Code will immediately suggest this plugin. It adds all the necessary features like:

Syntax highlighting for Python files
Intellisense (code-completion suggestions)
Ability to start a debugger

2. Bracket Pair Colorizer

by CoenraadS

This extension allows matching brackets to be identified with colors. The user can define which tokens to match, and which colors to use.

3. Better Comments

by Aaron Bond

The Better Comments extension will help you create more human-friendly comments in your code.
With this extension, you will be able to categorize your annotations into, Alerts, Queries, TODOs.

4. Error Lens

by Alexander

Sometimes the error marks in VS Code are hard to spot (especially the “info” hints). If you don’t wrap lines, it’s even worse - the error can be in the part of the code not visible on the screen.
That’s why I’m using Error Lens. It lets me modify how the errors should be displayed. It can display the error message next to the line where it occurs and a Sublime-like error icon in the gutter (next to the line number)

5. Git Graph

by Mhutchie

If your working with code I assume you use a repository to safely store it. Git graph adds another dimension to the way you use the VS Code. It adds a nice user interface of your Git history and adds the ability to create/checkout new branches with the click of a button.

6. GitLens Git supercharged

by Eric Amodio

This extension has at the time of writing already has more than 5 million downloads! This extension is not only a game-changer it makes sure you use Git in other ways you normally wouldn’t have used it within your CLI.

7. Python Preview

by Dongli

This extension is really simple but extremely handy. It brings a visual view to VSCode for Python, which makes debugging code far simpler and likely quite a bit faster.

8. Bookmarks

by Alessandro Fragnani

This extension lets you bookmark locations in your code, easily list all your bookmarks in a sidebar, and move between them with keyboard shortcuts.

9. TODO Highlight

by Wayou Liu

Highlights all TODO/FIXME/NOTE in the code, so you can easily spot them. You can easily customize it by adding new words and changing the highlight style.

10. Python Indent

by Kevin Rose

Every time you press the Enter key in a python context, this extension will parse your python file up to the location of your cursor, and determine exactly how much the next line (or two in the case of hanging indents) should be indented and how much nearby lines should be un-indented.

Conclusion

These are my top extensions for python that I am using in 2020, there are of-course more extensions that I am using (Django-snippets, Flask-snippets) but I wanted to focus on the extensions that I am using for python only. If you have an extension that is not included in this list, please share it in the comments. Happy Coding!

How to Open File Explorer Using Command Prompt on Windows 10

Ritul Singh — Thu, 22 Oct 2020 17:30:30 +0000

While there are quicker ways to open File Explorer, you can use Command Prompt to open the file manager in the current directory (or any other directory) in Windows 10. Here’s how.

Open File Explorer Using Command Prompt

To begin with, open Command Prompt on your PC by opening the "Start" menu, composing "cmd" in the Windows Search bar, at that point choosing "Order Prompt" from the list items.

Command Prompt will now open. Here, run the following command to open the File Explorer:

The . in the command represents the current directory in the command prompt. This command will open the folder in File Explorer that reflects that directory.
To open the parent folder of the current directory, run this command instead:

start ..

The parent folder of the current directory will now open in File Explorer.

You can keep going back in the directory by appending a backslash and two periods. For example, we’re currently in the “C Program” folder in Command Prompt. Running start .... will open the “D drive” folder in File Explorer—a folder two levels up from the current directory in Command Prompt.

Open a Specific Folder in File Explorer Using Command Prompt

You can change directories in Command Prompt by using the cd command and running the start . command once in the desired directory to open that folder in File Explorer. However, you can also open any folder in File Explorer by running the start command, followed by the path of the folder you’d like to open.

For example, in our current directory, C:\Users\Ritul Singh, we want to open the Documents folder in File Explorer, which is just one level down. To do so, we’d run the following command:

start Documents