reuploading assignments to git

assignment1/README.md

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+# Docker Web Application Deployment
+
+The application consists of two services:
+
+1. **Web Service (Nginx):**
+   - Uses the official Nginx image.
+   - Listens on port 80 inside the container and is mapped to host port 8080.
+2. **Database Service (MySQL 5.7):**
+   - Uses the official MySQL 5.7 image.
+   - Configured with a root password and a default database.
+   - Persists its data using the named volume `mysql-data`.
+
+## Files Overview
+
+- **prepare-app.sh:** 
+  - Creates the required Docker network (`myapp-net`) and persistent volume (`mysql-data`).
+- **docker-compose.yaml:**
+  - Defines the two services along with their ports, environment variables, volumes, and restart policies.
+- **start-app.sh:**
+  - Starts the services using Docker Compose in detached mode.
+  - Displays the URL to access the web service.
+- **stop-app.sh:**
+  - Stops the running containers without deleting the persistent volume.
+- **remove-app.sh:**
+  - Removes all the created resources (containers, network, and volume) from the deployment.
+
+## Deployment Instructions
+
+1. **Preparation:**
+   - Ensure Docker and Docker Compose are installed.
+   - Make the scripts executable:
+     ```bash
+     chmod +x prepare-app.sh start-app.sh stop-app.sh remove-app.sh
+     ```
+   - Run the preparation script:
+     ```bash
+     ./prepare-app.sh
+     ```
+
+2. **Starting the Application:**
+   - Launch the services by running:
+     ```bash
+     ./start-app.sh
+     ```
+   - Open your web browser and navigate to [http://localhost:8080](http://localhost:8080) to see the Nginx welcome page.
+
+3. **Stopping the Application:**
+   - Stop the services without losing data:
+     ```bash
+     ./stop-app.sh
+     ```
+
+4. **Removing the Application:**
+   - To completely remove all deployed resources, run:
+     ```bash
+     ./remove-app.sh
+     ```
+
+## Notes
+
+- The application uses an external network (`myapp-net`) and a persistent volume (`mysql-data`) that are created in `prepare-app.sh`.
+- The Nginx container depends on the MySQL container to demonstrate inter-service communication within the `myapp-net` network.
+- Containers are configured to restart on failure.
+

assignment1/docker-compose.yaml

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+version: '3.8'
+
+services:
+  web:
+    image: nginx:latest
+    ports:
+      - "8080:80"          
+    networks:
+      - myapp-net
+    restart: on-failure
+    depends_on:
+      - db
+
+  db:
+    image: mysql:5.7
+    environment:
+      MYSQL_ROOT_PASSWORD: example
+      MYSQL_DATABASE: appdb
+    volumes:
+      - mysql-data:/var/lib/mysql
+    networks:
+      - myapp-net
+    restart: on-failure
+
+networks:
+  myapp-net:
+    external: true
+
+volumes:
+  mysql-data:
+    external: true
+

assignment1/prepare-app.sh

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+#!/bin/bash
+# prepare-app.sh
+
+if ! docker network ls | grep -w myapp-net >/dev/null; then
+  docker network create myapp-net
+  echo "Created Docker network: myapp-net"
+else
+  echo "Docker network myapp-net already exists."
+fi
+
+
+if ! docker volume ls | grep -w mysql-data >/dev/null; then
+  docker volume create mysql-data
+  echo "Created Docker volume: mysql-data"
+else
+  echo "Docker volume mysql-data already exists."
+fi
+
+echo "Preparation complete."
+

assignment1/remove-app.sh

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+#!/bin/bash
+# remove-app.sh
+
+docker-compose down
+
+docker volume rm mysql-data
+docker network rm myapp-net
+
+echo "All application resources removed."
+

assignment1/start-app.sh

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+#!/bin/bash
+# start-app.sh
+
+docker-compose up -d
+
+sleep 5
+
+echo "Application started. Access the web service at http://localhost:8080"
+

assignment1/stop-app.sh

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+#!/bin/bash
+# stop-app.sh
+
+docker-compose stop
+echo "Application services stopped. Persistent data remains intact."
+

assignment2/Dockerfile

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+FROM nginx:alpine
+COPY weather.html /usr/share/nginx/html/index.html

assignment2/Dockerfile.api

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+FROM node:18-alpine
+WORKDIR /app
+COPY server.js .
+RUN npm init -y && npm install express pg body-parser
+EXPOSE 3000
+CMD ["node", "server.js"]

assignment2/README.md

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+#  Weather Web App - Kubernetes Deployment
+
+This project deploys a full-stack weather web application to Kubernetes. It includes:
+- A frontend website to search weather by city
+- A backend PostgreSQL database for logging searches
+- A Node.js API to connect the frontend to the database
+
+---
+
+##  Application Description
+
+- **Frontend (weather.html):** A responsive, modern web UI that shows current weather data using the OpenWeatherMap API.
+- **Backend (PostgreSQL):** Stores weather search history via a `weather_log` table.
+- **API Server (Node.js):** Receives weather data from the frontend and logs it to the PostgreSQL database.
+
+---
+
+##  Containers Used
+
+| Container         | Image              | Description                                  |
+|------------------|--------------------|----------------------------------------------|
+| `weather-frontend` | Custom Nginx-based | Serves the `weather.html` UI                 |
+| `postgres`        | `postgres:15`      | Provides relational database backend         |
+| `weather-api`     | Custom Node.js     | API that logs weather data to PostgreSQL     |
+
+---
+
+## ☸️ Kubernetes Objects
+
+| Object Type            | File                 | Description                                                          |
+|------------------------|----------------------|----------------------------------------------------------------------|
+| `Namespace`            | (inside script)       | Isolates resources under `webapp-ns`                                 |
+| `Deployment`           | `deployment.yaml`     | Manages frontend app                                                 |
+| `Deployment`           | `deployment-api.yaml` | Manages the Node.js API                                              |
+| `StatefulSet`          | `statefulset.yaml`    | Manages PostgreSQL instance with persistent volume                   |
+| `PersistentVolume`     | `statefulset.yaml`    | Host-mounted volume for PostgreSQL data                              |
+| `PersistentVolumeClaim`| `statefulset.yaml`    | Requests storage for StatefulSet                                     |
+| `Service`              | `service.yaml`        | Exposes frontend via NodePort                                        |
+| `Service`              | `deployment-api.yaml` | Exposes API via NodePort                                             |
+| `ConfigMap`            | Created by script     | Stores `init-db.sql` used to create the `weather_log` table          |
+
+---
+
+##  Networking & Volumes
+
+### Virtual Networks:
+- Kubernetes handles inter-service communication via internal DNS and `ClusterIP` services.
+- Frontend and backend are externally reachable using `NodePort` services.
+
+### Volumes:
+- `PersistentVolume` and `PersistentVolumeClaim` ensure PostgreSQL data is retained.
+- `ConfigMap` mounts the SQL init script for PostgreSQL setup.
+
+---
+
+## ⚙️ Container Configurations
+
+### Frontend
+- Dockerfile uses `nginx:alpine`
+- Serves `weather.html` (renamed as `index.html` inside container)
+- Exposed on port `80`
+
+### Node.js API
+- Built with Node.js 18
+- Listens on port `3000`
+- Connects to PostgreSQL using service DNS
+- Accepts POST requests at `/log` with weather data
+
+### PostgreSQL
+- `postgres:15` with `weatheruser`, `weatherpass`, and `weatherdb`
+- Init script creates a `weather_log` table with a sample row
+
+---
+
+##  How to Use the Application
+
+### 1. Build Docker Images
+
+```bash
+./prepare-app.sh
+```
+
+### 2. Start the App (create namespace and apply all configs)
+
+```bash
+./start-app.sh
+```
+
+### 3. View the App
+
+```bash
+minikube service weather-service -n webapp-ns
+```
+
+Or get the NodePort manually:
+
+```bash
+kubectl get svc -n webapp-ns
+minikube ip
+```
+
+Then open:
+```
+http://<minikube-ip>:<frontend-nodeport>
+```
+
+### 4. Use the App
+- Enter a city
+- Weather will be shown
+- Data is logged in PostgreSQL automatically
+
+### 5. Stop and Clean Up
+
+```bash
+./stop-app.sh
+```
+
+---
+
+##  API Key Setup
+
+- Register at [OpenWeatherMap](https://openweathermap.org/api)
+- Get your free API key
+- Replace the placeholder in `weather.html`:
+
+```js
+const apiKey = "YOUR_API_KEY";
+```
+
+---
+
+##  Conclusion
+
+- Frontend calls OpenWeatherMap and logs data to your backend
+- PostgreSQL is prepped with a table to store queries
+- You can expand the API to serve saved data or stats

assignment2/deployment-api.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: weather-api
+  namespace: webapp-ns
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: weather-api
+  template:
+    metadata:
+      labels:
+        app: weather-api
+    spec:
+      containers:
+      - name: weather-api
+        image: weather-api:latest
+        ports:
+        - containerPort: 3000
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: weather-api-service
+  namespace: webapp-ns
+spec:
+  selector:
+    app: weather-api
+  ports:
+  - protocol: TCP
+    port: 3000
+    targetPort: 3000
+    nodePort: 31000
+  type: NodePort
+

assignment2/deployment.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: weather-frontend
+  namespace: webapp-ns
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: weather-frontend
+  template:
+    metadata:
+      labels:
+        app: weather-frontend
+    spec:
+      containers:
+      - name: weather-frontend
+        image: weather-frontend:latest
+        imagePullPolicy: IfNotPresent
+        ports:
+        - containerPort: 80
+

assignment2/init-db.sql

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+CREATE TABLE IF NOT EXISTS weather_log (
+    id SERIAL PRIMARY KEY,
+    city VARCHAR(100),
+    temperature DECIMAL(5,2),
+    description TEXT,
+    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+INSERT INTO weather_log (city, temperature, description)
+VALUES ('London', 15.5, 'partly cloudy');
+

assignment2/prepare-app.sh

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+#!/bin/bash
+
+IMAGE_NAME=weather-frontend
+IMAGE_TAG=latest
+
+echo "🔧 Building Docker image: $IMAGE_NAME:$IMAGE_TAG"
+docker build -t $IMAGE_NAME:$IMAGE_TAG .
+docker build -t weather-api:latest -f Dockerfile.api .
+
+echo "✅ Build complete."
+

assignment2/server.js

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+const express = require('express');
+const bodyParser = require('body-parser');
+const { Pool } = require('pg');
+
+const app = express();
+const port = 3000;
+
+app.use(bodyParser.json());
+
+const pool = new Pool({
+  host: 'postgres-0.postgres.webapp-ns.svc.cluster.local',
+  user: 'weatheruser',
+  password: 'weatherpass',
+  database: 'weatherdb',
+  port: 5432
+});
+
+app.post('/log', async (req, res) => {
+  const { city, temperature, description } = req.body;
+  try {
+    await pool.query(
+      'INSERT INTO weather_log (city, temperature, description) VALUES ($1, $2, $3)',
+      [city, temperature, description]
+    );
+    res.status(200).send('Logged!');
+  } catch (err) {
+    console.error(err);
+    res.status(500).send('Error saving data');
+  }
+});
+
+app.listen(port, () => {
+  console.log(`Weather API listening on port ${port}`);
+});
+

assignment2/service.yaml

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+apiVersion: v1
+kind: Service
+metadata:
+  name: weather-service
+  namespace: webapp-ns
+spec:
+  selector:
+    app: weather-frontend
+  ports:
+  - protocol: TCP
+    port: 80
+    targetPort: 80
+  type: NodePort
+

assignment2/start-app.sh

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+#!/bin/bash
+
+echo "🚀 Creating namespace 'webapp-ns'..."
+kubectl create namespace webapp-ns
+
+echo "📦 Deploying frontend app..."
+kubectl apply -f deployment.yaml
+kubectl apply -f service.yaml
+
+echo "🧾 Creating ConfigMap with init-db.sql..."
+kubectl create configmap db-init-script --from-file=init-db.sql=init-db.sql -n webapp-ns
+
+echo "🗄️ Deploying database backend..."
+kubectl apply -f statefulset.yaml
+kubectl apply -f deployment-api.yaml
+
+echo "✅ All resources created."

assignment2/statefulset.yaml

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+apiVersion: v1
+kind: PersistentVolume
+metadata:
+  name: postgres-pv
+  namespace: webapp-ns
+spec:
+  capacity:
+    storage: 1Gi
+  accessModes:
+    - ReadWriteOnce
+  hostPath:
+    path: "/mnt/data/postgres"
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: postgres-pvc
+  namespace: webapp-ns
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi
+---
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: postgres
+  namespace: webapp-ns
+spec:
+  serviceName: "postgres"
+  replicas: 1
+  selector:
+    matchLabels:
+      app: postgres
+  template:
+    metadata:
+      labels:
+        app: postgres
+    spec:
+      initContainers:
+      - name: init-db
+        image: postgres:15
+        env:
+        - name: POSTGRES_USER
+          value: "weatheruser"
+        - name: POSTGRES_PASSWORD
+          value: "weatherpass"
+        - name: POSTGRES_DB
+          value: "weatherdb"
+        volumeMounts:
+        - name: init-script
+          mountPath: /docker-entrypoint-initdb.d
+        - name: postgres-storage
+          mountPath: /var/lib/postgresql/data
+      containers:
+      - name: postgres
+        image: postgres:15
+        ports:
+        - containerPort: 5432
+        env:
+        - name: POSTGRES_USER
+          value: "weatheruser"
+        - name: POSTGRES_PASSWORD
+          value: "weatherpass"
+        - name: POSTGRES_DB
+          value: "weatherdb"
+        volumeMounts:
+        - name: postgres-storage
+          mountPath: /var/lib/postgresql/data
+      volumes:
+      - name: init-script
+        configMap:
+          name: db-init-script
+  volumeClaimTemplates:
+  - metadata:
+      name: postgres-storage
+    spec:
+      accessModes: ["ReadWriteOnce"]
+      resources:
+        requests:
+          storage: 1Gi
+

assignment2/stop-app.sh

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+#!/bin/bash
+
+echo "🧼 Deleting all resources in namespace 'webapp-ns'..."
+kubectl delete namespace webapp-ns
+
+echo "✅ Cleanup complete."
+

assignment2/weather.html

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+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+  <title>Weather Info</title>
+  <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600&display=swap" rel="stylesheet">
+  <style>
+    * {
+      box-sizing: border-box;
+    }
+
+    body {
+      font-family: 'Inter', sans-serif;
+      background: linear-gradient(to right, #e0f7fa, #80deea);
+      margin: 0;
+      padding: 0;
+      display: flex;
+      justify-content: center;
+      align-items: center;
+      height: 100vh;
+    }
+
+    .container {
+      background: white;
+      padding: 2rem;
+      border-radius: 1rem;
+      box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
+      width: 100%;
+      max-width: 400px;
+      text-align: center;
+    }
+
+    h1 {
+      margin-bottom: 1.5rem;
+      font-size: 1.75rem;
+      font-weight: 600;
+      color: #00796b;
+    }
+
+    input {
+      padding: 0.5rem;
+      width: 65%;
+      border: 1px solid #ccc;
+      border-radius: 5px;
+      margin-right: 0.5rem;
+      font-size: 1rem;
+    }
+
+    button {
+      padding: 0.55rem 1rem;
+      background-color: #00796b;
+      color: white;
+      border: none;
+      border-radius: 5px;
+      font-size: 1rem;
+      cursor: pointer;
+    }
+
+    button:hover {
+      background-color: #00695c;
+    }
+
+    #weather {
+      margin-top: 2rem;
+      font-size: 1.1rem;
+    }
+
+    #weather p {
+      margin: 0.25rem 0;
+    }
+  </style>
+</head>
+<body>
+  <div class="container">
+    <h1>🌦️ Check the Weather</h1>
+    <input type="text" id="city" placeholder="Enter city" />
+    <button onclick="getWeather()">Get Weather</button>
+    <div id="weather"></div>
+  </div>
+
+  <script>
+    async function getWeather() {
+      const city = document.getElementById("city").value;
+      const apiKey = "0ef7f5ac4207c6da232b7843eb1a663e"; 
+
+      try {
+        const res = await fetch(
+          `https://api.openweathermap.org/data/2.5/weather?q=${city}&units=metric&appid=${apiKey}`
+        );
+        const data = await res.json();
+
+        if (data.cod === 200) {
+          document.getElementById("weather").innerHTML = `
+            <h2>${data.name}, ${data.sys.country}</h2>
+            <p><strong>${data.weather[0].description}</strong></p>
+            <p>🌡️ <strong>${data.main.temp}°C</strong></p>
+          `;
+
+          // Log to backend
+          await fetch("http://192.168.49.2:31000/log", {
+            method: "POST",
+            headers: { "Content-Type": "application/json" },
+            body: JSON.stringify({
+              city: data.name,
+              temperature: data.main.temp,
+              description: data.weather[0].description
+            })
+          });
+
+        } else {
+          document.getElementById("weather").innerHTML = `<p style="color:red;">City not found!</p>`;
+        }
+      } catch (err) {
+        console.error("Fetch failed:", err);
+        document.getElementById("weather").innerHTML = `<p style="color:red;">Error getting weather data.</p>`;
+      }
+    }
+  </script>
+</body>
+</html>
+