DEV Community: Munisekhar Udavalapati

Tailwind CSS Complete Documentation

Munisekhar Udavalapati — Mon, 31 Mar 2025 06:30:27 +0000

Introduction to Tailwind CSS

Tailwind CSS is a utility-first CSS framework that provides low-level utility classes to build custom designs quickly without writing custom CSS.

Installation

To use Tailwind CSS, install it via npm:

npm install -D tailwindcss
npx tailwindcss init

Include it in your CSS:

@tailwind base;
@tailwind components;
@tailwind utilities;

Utility Classes in Tailwind CSS

1. Layout Utilities

CSS Property	Tailwind Class
`display: flex;`	`flex`
`display: grid;`	`grid`
`justify-content: center;`	`justify-center`
`align-items: center;`	`items-center`
`width: 100%;`	`w-full`
`max-width: 1200px;`	`max-w-7xl`
`height: 100vh;`	`h-screen`

2. Spacing Utilities

CSS Property	Tailwind Class
`margin: 1rem;`	`m-4`
`margin-left: auto; margin-right: auto;`	`mx-auto`
`padding: 0.5rem;`	`p-2`
`padding-left: 1rem; padding-right: 1rem;`	`px-4`

3. Typography Utilities

CSS Property	Tailwind Class
`font-size: 1.5rem;`	`text-2xl`
`font-weight: bold;`	`font-bold`
`text-align: center;`	`text-center`
`line-height: 1.75;`	`leading-relaxed`
`letter-spacing: 0.1em;`	`tracking-wide`

4. Color Utilities

CSS Property	Tailwind Class
`background-color: blue;`	`bg-blue-500`
`color: gray;`	`text-gray-800`
`border-color: gray;`	`border-gray-300`

5. Border Utilities

CSS Property	Tailwind Class
`border-width: 2px;`	`border-2`
`border-radius: 8px;`	`rounded-lg`

Table Styling in Tailwind CSS

Tailwind provides utilities to style tables efficiently.

Basic Table Structure

<table class="table-auto border-collapse border border-gray-300 w-full">
  <thead>
    <tr class="bg-gray-200">
      <th class="border border-gray-300 px-4 py-2">Name</th>
      <th class="border border-gray-300 px-4 py-2">Age</th>
      <th class="border border-gray-300 px-4 py-2">City</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td class="border border-gray-300 px-4 py-2">John Doe</td>
      <td class="border border-gray-300 px-4 py-2">25</td>
      <td class="border border-gray-300 px-4 py-2">New York</td>
    </tr>
    <tr class="bg-gray-100">
      <td class="border border-gray-300 px-4 py-2">Jane Smith</td>
      <td class="border border-gray-300 px-4 py-2">30</td>
      <td class="border border-gray-300 px-4 py-2">Los Angeles</td>
    </tr>
  </tbody>
</table>

Table Styling Classes

CSS Property	Tailwind Class
`width: auto;`	`table-auto`
`width: 100%;`	`w-full`
`border: 1px solid;`	`border`
`border-collapse: collapse;`	`border-collapse`
`border-spacing: 2px;`	`border-separate`
`padding: 16px;`	`p-4`
`background-color: #f7fafc;`	`bg-gray

Deploying a NestJS App with MongoDB on GCP

Munisekhar Udavalapati — Wed, 19 Mar 2025 06:42:57 +0000

🚀 Deploying a NestJS App with MongoDB on GCP using Docker and Kubernetes

Step 1: Set Up GCP

1️⃣ Create a GCP Account

Go to Google Cloud Console.
Create a new project.

2️⃣ Enable Required APIs

Navigate to APIs & Services > Library and enable the following:
- Kubernetes Engine API
- Cloud Build API
- Container Registry API
- Compute Engine API

3️⃣ Install Google Cloud SDK

curl https://sdk.cloud.google.com | bash
exec -l $SHELL
gcloud init

4️⃣ Authenticate and Set Your Project

gcloud auth login
gcloud config set project YOUR_PROJECT_ID

Step 2: Install Dependencies

Ensure you have the following installed:

Docker: Download
Kubectl: Download
Google Cloud SDK: Installed in the previous step
Node.js and NestJS (already installed for your project)

Step 3: Dockerize Your NestJS Application

1️⃣ Create a `Dockerfile`

# Use official Node.js image
FROM node:18

# Set working directory
WORKDIR /app

# Copy package.json and install dependencies
COPY package*.json ./
RUN npm install

# Copy the rest of the application
COPY . .

# Build the NestJS app
RUN npm run build

# Expose the port
EXPOSE 3000

# Start the application
CMD ["npm", "run", "start"]

2️⃣ Create a `.dockerignore` file

node_modules
dist
.env

3️⃣ Build and Tag the Docker Image

docker build -t gcr.io/YOUR_PROJECT_ID/nestjs-app .

4️⃣ Push the Image to Google Container Registry (GCR)

gcloud auth configure-docker
docker push gcr.io/YOUR_PROJECT_ID/nestjs-app

Step 4: Set Up MongoDB on GCP

Option 1️⃣: Use MongoDB Atlas (Recommended)

Sign up at MongoDB Atlas.
Create a free cluster and get the connection string.
Update your .env file:

DATABASE_URL=mongodb+srv://username:password@cluster.mongodb.net/dbname

Option 2️⃣: Deploy MongoDB on GKE

Create a Persistent Volume

mongo-pv.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mongo-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

Deploy MongoDB

mongo-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mongo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongo
  template:
    metadata:
      labels:
        app: mongo
    spec:
      containers:
        - name: mongo
          image: mongo:latest
          ports:
            - containerPort: 27017
          volumeMounts:
            - name: mongo-storage
              mountPath: /data/db
      volumes:
        - name: mongo-storage
          persistentVolumeClaim:
            claimName: mongo-pvc

Expose MongoDB

mongo-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: mongo
spec:
  selector:
    app: mongo
  ports:
    - protocol: TCP
      port: 27017
      targetPort: 27017

Apply MongoDB Configurations

kubectl apply -f mongo-pv.yaml
kubectl apply -f mongo-deployment.yaml
kubectl apply -f mongo-service.yaml

Step 5: Deploy NestJS to GKE

1️⃣ Create a Kubernetes Deployment

nestjs-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nestjs-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nestjs-app
  template:
    metadata:
      labels:
        app: nestjs-app
    spec:
      containers:
        - name: nestjs-app
          image: gcr.io/YOUR_PROJECT_ID/nestjs-app
          ports:
            - containerPort: 3000
          env:
            - name: DATABASE_URL
              value: "mongodb://mongo:27017/mydatabase"

2️⃣ Expose the Application

nestjs-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: nestjs-service
spec:
  type: LoadBalancer
  selector:
    app: nestjs-app
  ports:
    - protocol: TCP
      port: 80
      targetPort: 3000

3️⃣ Deploy the NestJS App

kubectl apply -f nestjs-deployment.yaml
kubectl apply -f nestjs-service.yaml

Step 6: Configure GKE (Google Kubernetes Engine)

1️⃣ Create a Kubernetes Cluster

gcloud container clusters create nestjs-cluster --num-nodes=2

2️⃣ Get Cluster Credentials

gcloud container clusters get-credentials nestjs-cluster

3️⃣ Deploy Kubernetes Resources

kubectl apply -f mongo-deployment.yaml
kubectl apply -f mongo-service.yaml
kubectl apply -f nestjs-deployment.yaml
kubectl apply -f nestjs-service.yaml

4️⃣ Get the External IP of the Application

kubectl get service nestjs-service

Use the EXTERNAL-IP to access your NestJS API.

Step 7: Set Up Domain and SSL (Optional)

Use Google Cloud Load Balancer for a custom domain.
Use Cert-Manager for HTTPS with Let's Encrypt.

Step 8: Monitor and Scale

Check Logs

kubectl logs -f deployment/nestjs-app

Scale Application

kubectl scale deployment nestjs-app --replicas=3

🎉 Congratulations! Your NestJS app is now running on GCP with MongoDB using Docker and Kubernetes. 🚀

Mongoose with NestJS and MongoDB: A Complete Guide || By Munisekhar Udavalapati

Munisekhar Udavalapati — Mon, 10 Mar 2025 13:28:55 +0000

Introduction

Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node.js. It provides schema validation, middleware, and built-in query-building methods. In this guide, we will integrate Mongoose with NestJS to create a structured and scalable backend application using MongoDB.

Prerequisites

Basic knowledge of TypeScript and NestJS
Installed Node.js and NestJS CLI
A running instance of MongoDB (local or cloud-based)

Installing Dependencies

To use Mongoose with NestJS, install the required packages:

npm install @nestjs/mongoose mongoose

For TypeScript types:

npm install -D @types/mongoose

Setting Up Mongoose in NestJS

NestJS provides MongooseModule to manage MongoDB connections. Add it to the root module:

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';

@Module({
  imports: [MongooseModule.forRoot('mongodb://localhost:27017/nestjs-app', {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  })],
})
export class AppModule {}

Understanding Mongoose Concepts

1. Schema

Defines the structure of documents in a collection.

2. Model

A wrapper for the schema that allows interacting with the database.

3. Document

An instance of a model that represents a single record.

4. Middleware

Functions that execute before or after certain actions (e.g., saving a document).

5. Virtuals

Computed properties that are not stored in the database.

6. Hooks

Functions that run before or after certain Mongoose operations (e.g., pre-save, post-save).

Creating a Mongoose Schema and Model

Define a schema using decorators with @nestjs/mongoose.

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import { Document } from 'mongoose';

@Schema({ timestamps: true })
export class User extends Document {
  @Prop({ required: true })
  name: string;

  @Prop({ unique: true, required: true })
  email: string;

  @Prop({ default: Date.now })
  createdAt: Date;
}

export const UserSchema = SchemaFactory.createForClass(User);

Adding Middleware (Hooks)

Middleware functions allow executing logic before or after certain events like saving a document.

UserSchema.pre('save', function(next) {
  console.log('User is being saved:', this);
  next();
});

Defining Virtuals

Virtuals allow creating computed properties that do not get stored in MongoDB.

UserSchema.virtual('fullName').get(function() {
  return `${this.firstName} ${this.lastName}`;
});

Registering the Schema in the Module

To use the schema, register it in a module:

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';
import { User, UserSchema } from './user.schema';
import { UserService } from './user.service';
import { UserController } from './user.controller';

@Module({
  imports: [MongooseModule.forFeature([{ name: User.name, schema: UserSchema }])],
  controllers: [UserController],
  providers: [UserService],
})
export class UserModule {}

Creating a Service for Database Operations

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { User } from './user.schema';

@Injectable()
export class UserService {
  constructor(@InjectModel(User.name) private userModel: Model<User>) {}

  async createUser(name: string, email: string): Promise<User> {
    const newUser = new this.userModel({ name, email });
    return newUser.save();
  }
}

Querying with Mongoose

Find all users:

async getUsers(): Promise<User[]> {
  return this.userModel.find().exec();
}

Find by ID:

async getUserById(id: string): Promise<User> {
  return this.userModel.findById(id).exec();
}

Select Specific Fields:

async getUserByEmail(email: string): Promise<User> {
  return this.userModel.findOne({ email }).select('name email').exec();
}

Using Indexes for Performance Optimization

UserSchema.index({ email: 1 });

Find with Filtering:

async getUsersByCreatedDate(date: Date): Promise<User[]> {
  return this.userModel.find({ createdAt: { $gte: date } }).exec();
}

Sorting Results:

async getUsersSorted(): Promise<User[]> {
  return this.userModel.find().sort({ name: 1 }).exec();
}

Pagination with Limit & Skip:

async getUsersPaginated(page: number, limit: number): Promise<User[]> {
  return this.userModel.find().skip((page - 1) * limit).limit(limit).exec();
}

Transactions in MongoDB

To ensure atomic operations, use MongoDB transactions:

const session = await this.userModel.db.startSession();
session.startTransaction();
try {
  const user = new this.userModel({ name, email });
  await user.save({ session });
  await session.commitTransaction();
} catch (error) {
  await session.abortTransaction();
} finally {
  session.endSession();
}

Best Practices

Use DTOs for validation and request handling
Enable indexes for better query performance
Use MongoDB Transactions for atomic operations
Implement middleware for logging and error handling
Keep schema definitions clean and structured
Use .select() to fetch only necessary fields for efficiency
Use .sort(), .skip(), and .limit() for better data retrieval management

Conclusion

This guide covers setting up Mongoose with NestJS, defining schemas, implementing CRUD operations, handling transactions, indexing, filtering, and best practices. With this foundation, you can build powerful and optimized applications using NestJS and MongoDB.

🔥 NestJS Middleware: Logging Requests with Ease! || By Munisekhar Udavalapati

Munisekhar Udavalapati — Fri, 07 Mar 2025 06:36:27 +0000

🔥 Middleware in NestJS

1️⃣ What is Middleware?

Middleware in NestJS is a function that runs before the request reaches the controller. It can be used for:

✅ Logging requests

✅ Authentication

✅ Modifying request data

✅ Blocking unauthorized requests

🔥 Task 1: Create a Logging Middleware

Step 1: Create a Middleware File

Inside src/, create a new file: logger.middleware.ts

Step 2: Write the Middleware Code

import { Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';

@Injectable()
export class LoggerMiddleware implements NestMiddleware {
  use(req: Request, res: Response, next: NextFunction) {
    console.log(`[${new Date().toISOString()}] ${req.method} ${req.url}`);
    next();
  }
}

✔ This middleware logs the method and URL of every request.

✔ next() → Passes control to the next handler (controller or another middleware).

🔥 Task 2: Apply Middleware in `app.module.ts`

Modify src/app.module.ts to apply the middleware:

import { MiddlewareConsumer, Module, NestModule } from '@nestjs/common';
import { UserModule } from './user/user.module';
import { LoggerMiddleware } from './logger.middleware';

@Module({
  imports: [UserModule],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(LoggerMiddleware).forRoutes('*'); // Apply to all routes
  }
}

✔ This applies the logging middleware to all routes in the app.

🔥 Task 3: Test the Middleware

1️⃣ Start the server

Run the following command:

npm run start

2️⃣ Send a request

Make a GET request to:

http://localhost:3000/user

3️⃣ Check the terminal

You should see logs like:

[2025-03-06T10:30:00.123Z] GET /user

🚀 Bonus: Logging Request Body for POST Requests

Modify the logger.middleware.ts file to log the request body only for POST requests:

import { Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';

@Injectable()
export class LoggerMiddleware implements NestMiddleware {
  use(req: Request, res: Response, next: NextFunction) {
    console.log(`[${new Date().toISOString()}] ${req.method} ${req.url}`);

    // Log request body for POST requests
    if (req.method === 'POST') {
      console.log('Request Body:', JSON.stringify(req.body));
    }

    next();
  }
}

Now, when you send a POST request, the terminal will display:

[2025-03-06T10:31:00.456Z] POST /user
Request Body: {"name":"John","email":"john@example.com"}

✅ Your Task

🔥 Implement the logging middleware in your NestJS project.

🔥 Modify it to log the request body for POST requests.

🔥 Test it and drop your thoughts in the comments! 🚀

💬 What do you think?

Do you use middleware in your NestJS projects? Share your experience in the comments! 🎯

📌Important GCP Commands for Developers By Munisekhar Udavalapati

Munisekhar Udavalapati — Thu, 06 Mar 2025 10:29:37 +0000

# 📌 Important GCP Commands for Developers

## 🔍 Cloud Run Logs & Monitoring

🔹 View Cloud Run Logs

gcloud logs read --format=json --limit=50

🔹 View Logs for a Specific Service

gcloud run logs read nest-app --region us-central1

🔹 Stream Logs in Real-Time

gcloud run logs tail --region us-central1

## 📜 Kubernetes (kubectl) Logs & Monitoring

🔹 View Logs for a Pod

kubectl logs <pod-name>

🔹 View Logs for a Pod with Multiple Containers

kubectl logs <pod-name> -c <container-name>

🔹 Stream Logs in Real-Time

kubectl logs -f <pod-name>

🔹 View Logs for All Pods in a Namespace

kubectl logs --all-containers=true -n <namespace>

🔹 View Events in the Cluster

kubectl get events --sort-by=.metadata.creationTimestamp

## 🏗️ Managing Cloud Run Services

🔹 List All Deployed Services

gcloud run services list

🔹 Update Existing Deployment

gcloud run deploy nest-app --image gcr.io/$PROJECT_ID/nest-app --region us-central1

🔹 Delete a Cloud Run Service

gcloud run services delete nest-app --region us-central1

## 💻 Compute Engine VM Management

🔹 SSH into Compute Engine VM

gcloud compute ssh your-vm-instance-name --zone=us-central1-a

🔹 List All Running VM Instances

gcloud compute instances list

🔹 Start a Compute Engine VM

gcloud compute instances start your-vm-instance-name --zone=us-central1-a

🔹 Stop a Compute Engine VM

gcloud compute instances stop your-vm-instance-name --zone=us-central1-a

🔹 Delete a Compute Engine VM

gcloud compute instances delete your-vm-instance-name --zone=us-central1-a

## 📦 Container Registry & Images

🔹 List All Docker Images in Container Registry

gcloud container images list

🔹 Delete a Docker Image from Container Registry

gcloud container images delete gcr.io/$PROJECT_ID/nest-app

✅ Final Notes

Always use --region=<your-region> when working with GCP services.
Use gcloud config list to check active project settings.
Use gcloud help to explore more available commands.

🚀 Happy coding! 🔥

🚀 Deploy NestJS Application on GCP By Munisekhar Udavalapati

Munisekhar Udavalapati — Thu, 06 Mar 2025 10:21:30 +0000

# 🚀 Deploy NestJS Application on GCP for Free

## 1️⃣ Create a Google Cloud Account

Go to Google Cloud Console
Sign up for $300 free credits (valid for 90 days).
Enable Billing (required even for free-tier services).

## 2️⃣ Install Required CLI Tools

# Install Google Cloud SDK
curl -O https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-sdk-441.0.0-linux-x86_64.tar.gz
tar -xvzf google-cloud-sdk-*.tar.gz
./google-cloud-sdk/install.sh

# Restart terminal and initialize GCP CLI
gcloud init

Authenticate with your Google account.
Set your default project and region.

## 3️⃣ Enable Required GCP Services

gcloud services enable run.googleapis.com containerregistry.googleapis.com artifactregistry.googleapis.com

## 4️⃣ Clone Your GitHub Repository

git clone <YOUR_GITHUB_REPO_URL>
cd <YOUR_PROJECT_FOLDER>

## 5️⃣ Create a Dockerfile (if not already present)

# Use official Node.js image
FROM node:18

# Set the working directory
WORKDIR /app

# Copy package.json and install dependencies
COPY package*.json ./
RUN npm install

# Copy the rest of the app files
COPY . .

# Build the app
RUN npm run build

# Expose the port
EXPOSE 3000

# Start the application
CMD ["npm", "run", "start"]

## 6️⃣ Build and Push Docker Image to GCP

# Authenticate Docker with Google Cloud
gcloud auth configure-docker

# Set your project ID
export PROJECT_ID=$(gcloud config get-value project)

# Build the Docker image
docker build -t gcr.io/$PROJECT_ID/nest-app .

# Push the image to Google Container Registry
docker push gcr.io/$PROJECT_ID/nest-app

## 7️⃣ Deploy to Cloud Run

gcloud run deploy nest-app \
  --image gcr.io/$PROJECT_ID/nest-app \
  --platform managed \
  --region us-central1 \
  --allow-unauthenticated

Service name → Press Enter (default: nest-app)
Region → Choose us-central1 (free tier)
Allow unauthenticated → y (for public access)

## 8️⃣ Get the Live URL

Service [nest-app] revision [nest-app-xxxxx] has been deployed and is serving traffic at:
https://nest-app-xxxxxxxxxx-uc.a.run.app

🎉 Your NestJS app is live! 🚀

## 9️⃣ Optional: Connect a Custom Domain

Go to Cloud Run > Your Service > Custom Domains
Follow the setup process to map your domain.

✅ Final Notes

Cloud Run provides 2 million free requests per month.
For databases, consider Firestore (free tier available).
Want a free VM? Use Compute Engine (e2-micro instance).

🚀 Happy coding! 🔥

Nest JS Documentation 1

Munisekhar Udavalapati — Fri, 21 Feb 2025 17:22:02 +0000

Installation Nest JS

$ npm i -g @nestjs/cli
$ nest new project-name

Alternatives Way To Install Nest JS

$ git clone https://github.com/nestjs/typescript-starter.git project
$ cd project
$ npm install
$ npm run start

Decorators In NestJS

┌───────────────────────┬──────────────────┬──────────────────────────────┐
│ Type                  │ Example          │ Use Case                      │
├───────────────────────┼──────────────────┼──────────────────────────────┤
│ Class Decorators      │ @Controller()    │ Defines controllers & modules │
│ Method Decorators     │ @Get(), @Post()  │ Handles HTTP requests         │
│ Property Decorators   │ @Inject()        │ Injects dependencies          │
│ Parameter Decorators  │ @Param(), @Body()│ Extracts request data         │
│ Custom Decorators     │ @Log()           │ Adds reusable logic           │
└───────────────────────┴──────────────────┴──────────────────────────────┘

constrollers
controllers can handel the incoming requests
and sending to the response to the clint

Example for to create simple API using Controller and Get Decorator

import {Controller, Get} from '@nestjs/common';

@Controller('all-students')
export class allStudents(){
 @Get()
 findAllStudents():string{
  return "This is All Students Response"
 }
}

Providers In NestJs
In NestJs Provider is a class that can be Injected into other classes using Dependency Injection (ID)

Example user.service.ts

import {Injectable} from '@nestjs/common';

@Injectable()
export class UserService{
 private users=[
  {id:1,name:"Aishwary"},
  {id:2,name:"Harsh"},
  {id:3,name:"Ambuj"},
  {id:4,name:"Somyadeb"},
  {id:5,name:"Shubham"},
  {id:6,name:"Anish"}
 ];

 getUserById(id:number){
  return this.user.find(user=>user.id===id);
 }
}

Example user.controller.ts

import {Controller,Get,Param} from '@nestjs/common';
import {UserService} from './user.service';

export class UserController{
 constructor(private readonly userService:UserServivce){}

 @Get('user')
 getUser(@Param(':id')id:string){
  return this.userService.getUserById(Number(id));
 }
}

Example user.module.ts

import {module} from '@nestjs/common';
import {UserSerive} from './user.service';
import {UserController} from './uer.controller';

@Module({
 controllers:[UserController],
 providers:[Userservice],
)}
export class UserModule {}

Example app.module.ts

import {Module} from '@nestjs/common';
import {UserModule} from  './user/user.module';

@Module({
 import:[UserModule],
})
export class AppModuel{}

kubernetes documentation

Munisekhar Udavalapati — Thu, 06 Feb 2025 11:02:33 +0000

View Cluster Resources

kubectl get pods # List all pods
kubectl get deployments # List all deployments
kubectl get services # List all services

Inspect Specific Resources

kubectl describe pod # Get details about a specific pod
kubectl describe deployment # Get details about a specific deployment

Inspect Logs

kubectl logs # Get logs of a specific pod
kubectl logs -c # If there are multiple containers in the pod

Execute Commands in Pods

kubectl exec -it -- /bin/bash # Open a shell in a running pod
kubectl exec -it -- printenv # View environment variables inside a pod

Create and Expose a Deployment in a Local Cluster

kubectl create deployment hello-world --image=nginx
kubectl expose deployment hello-world --type=NodePort --port=80
kubectl get all

Step-by-Step Process of BBPS Biller Integration

Munisekhar Udavalapati — Mon, 03 Feb 2025 12:42:54 +0000

1. Understanding BBPS Participants

Before integration, you need to understand the key players:

BBPCU (Bharat Bill Payment Central Unit - NPCI): Governs and regulates BBPS.
BBPOU (Bharat Bill Payment Operating Unit): Banks & Non-Banks authorized by NPCI to onboard billers.
Biller (Merchant/Utility Company): The entity whose bills need to be paid.
Agent Institution (AI): Payment channels like apps, banks, and digital wallets.
Customer: End-user making payments.

2. Biller Onboarding Process

To integrate as a biller, follow these steps:

Step 1: Choose BBPOU

A biller cannot integrate directly with NPCI. You need to choose a BBPOU (like a bank or fintech) that will connect your system to BBPS.

Step 2: Submit Required Documents

Business registration proof (GST, PAN, etc.)
Bank details for settlement
Technical API specifications & compliance documents

Step 3: Agreement & Approval

Sign an agreement with the BBPOU.
NPCI verifies and approves the biller registration.

3. Technical Integration Process

After onboarding, technical integration begins.

Step 4: API Integration with BBPOU

BBPS follows an API-based architecture. The biller must integrate the following APIs:

Bill Fetch API – Retrieves customer bill details.
Bill Payment API – Processes customer payments.
Transaction Status API – Checks payment status.
Refund API (if applicable) – Handles reversals in case of failures.

BBPOU provides API specifications, security guidelines, and authentication mechanisms.

Step 5: Data Security & Compliance

Implement AES256 encryption for data security.
Follow PCI-DSS compliance (if handling card payments).
Use OAuth 2.0 or JWT for API authentication.

4. Testing & UAT (User Acceptance Testing)

Before going live, perform the following steps:

UAT Testing: Validate bill fetch, payment, and status update APIs.
NPCI Certification: BBPOU submits API test results to NPCI for certification.
Security Audit: Ensure the system follows BBPS security guidelines.

5. Go-Live & Monitoring

After approval, BBPOU enables the biller on the BBPS network. Customers can now pay bills via BBPS agents/apps.

Implement real-time transaction monitoring to detect issues.
Generate reconciliation reports to match transactions.

Benefits of BBPS Biller Integration

✅ Wider Customer Reach – Payments can be made from any BBPS-enabled app or bank.
✅ Real-Time Payment Settlement – Faster transactions and improved cash flow.
✅ Fraud Prevention – Secure API integration with encrypted communication.
✅ Better User Experience – Customers can fetch & pay bills seamlessly.
✅ Regulatory Compliance – NPCI ensures industry standards are followed.

Next Steps for Your BBPS QR Code System

Since you're implementing a QR code-based bill payment system, you'll need:

Generate QR Codes linked to biller/customer accounts.
Scan & Fetch Bill Details using BBPS Bill Fetch API.
Enable Payment Processing via BBPS Payment API.
Implement Notification & Reconciliation for success/failure tracking.

simplify bill payments for millions! 🚀

7. Reverse Integer

Munisekhar Udavalapati — Sat, 16 Nov 2024 14:01:43 +0000

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.

Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

Example 1:

Input: x = 123
Output: 321
Example 2:

Input: x = -123
Output: -321
Example 3:

Input: x = 120
Output: 21

`Constraints:

-231 <= x <= 231 - 1`

var reverse = function(x) {

    let bit = Math.pow(2,31) - 1   

    let rev= x.toString().split('').reverse().join('') 

    let result = parseInt(rev)

    if(result > (bit) || result < -(bit)){
        return 0
    }

    if(x<0){
        return -result
    }else{
        return result
    }
}

6. Zigzag Conversion

Munisekhar Udavalapati — Sun, 03 Nov 2024 14:34:51 +0000

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P A H N
A P L S I I G
Y I R
And then read line by line: "PAHNAPLSIIGYIR"

Write the code that will take a string and make this conversion given a number of rows:

string convert(string s, int numRows);

Example 1:
Input: s = "PAYPALISHIRING", numRows = 3
Output: "PAHNAPLSIIGYIR"
Example 2:
Input: s = "PAYPALISHIRING", numRows = 4
Output: "PINALSIGYAHRPI"
Explanation:
P     I    N
A   L S  I G
Y A   H R
P     I
Example 3:
Input: s = "A", numRows = 1
Output: "A"

Constraints:

1 <= s.length <= 1000
s consists of English letters (lower-case and upper-case), ',' and '.'.
1 <= numRows <= 1000

var convert = function(s, numRows) {
    let res = [];
    let count = 0;
    let up = true;
    for(let i =0; i<s.length;i++){

        if(!res[count]) res[count] = []
        res[count].push(s[i])

        count = up ? count+1 : count-1

        if(count+1 == numRows) up = false;
        else if(count == 0) up = true;
    }
    let result = ''
    for(let i of res){
        result += i.join('')
    }
    return result;
};

5. Longest Palindromic Substring

Munisekhar Udavalapati — Fri, 01 Nov 2024 14:46:30 +0000

Given a string s, return the longest
palindromic

substring
in s.

Example 1:
Input: s = "babad"
Output: "bab"
Explanation: "aba" is also a valid answer.

Example 2:
Input: s = "cbbd"
Output: "bb"