hafzalk

z1/z2/Dockerfile

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+FROM python:3.9-slim
+
+WORKDIR /app
+
+COPY app/ .
+
+RUN pip install --no-cache-dir -r requirements.txt
+
+CMD ["python", "main.py"]

z1/z2/README.md

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+# Flask + PostgreSQL Kubernetes Deployment
+
+This project deploys a Flask web application with a PostgreSQL backend using Kubernetes.
+
+## 🛠 Structure
+
+- `app/`: Flask source code (`main.py`, `requirements.txt`)
+- `k8s/`: Kubernetes manifests for deployments, services, namespace, etc.
+- `Dockerfile`: Builds the Flask app image
+- `prepare-app.sh`: Builds Docker image and prepares volumes
+- `start-app.sh`: Applies all Kubernetes objects
+- `stop-app.sh`: Deletes all Kubernetes resources
+- `statefulset.yaml`: Defines StatefulSet, PV, and PVC
+
+## 🚀 Steps to Deploy
+
+1. **Prepare the application:**
+   ```bash
+   ./prepare-app.sh
+
+
+hafzal03@LAPTOP-ELUS3HGM:~/mypro/z2$ kubectl get pods -n webapp-namespace
+NAME                        READY   STATUS    RESTARTS   AGE
+flask-app-6b844bf6-cq9t6    1/1     Running   0          8m37s
+postgres-644fc4c86d-l9h4f   1/1     Running   0          14m
+hafzal03@LAPTOP-ELUS3HGM:~/mypro/z2$ minikube service flask-service -n webapp-namespace
+
+minikube service flask-service -n webapp-namespace
+
+kubectl get pods -n webapp-namespace
+
+kubectl rollout restart deployment flask-app -n webapp-namespace

z1/z2/app/main.py

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+from flask import Flask, request, jsonify, render_template_string
+import psycopg2
+import os
+
+app = Flask(__name__)
+
+def get_db_connection():
+    return psycopg2.connect(
+        host=os.environ.get("POSTGRES_HOST"),
+        database=os.environ.get("POSTGRES_DB"),
+        user=os.environ.get("POSTGRES_USER"),
+        password=os.environ.get("POSTGRES_PASSWORD"),
+        port=os.environ.get("POSTGRES_PORT", 5432),
+    )
+
+def init_db():
+    conn = get_db_connection()
+    cur = conn.cursor()
+    cur.execute("""
+        CREATE TABLE IF NOT EXISTS students (
+            id SERIAL PRIMARY KEY,
+            name TEXT NOT NULL,
+            room_number TEXT NOT NULL,
+            faculty TEXT NOT NULL
+        );
+    """)
+    conn.commit()
+    cur.close()
+    conn.close()
+
+@app.route("/")
+def index():
+    return "<h1>Welcome!</h1><p>Go to /add to add a student, /students to view all.</p>"
+
+# HTML Form + POST Submission
+@app.route("/add", methods=["GET", "POST"])
+def add_student():
+    if request.method == "POST":
+        name = request.form.get("name")
+        room_number = request.form.get("room_number")
+        faculty = request.form.get("faculty")
+
+        if not name or not room_number or not faculty:
+            return "All fields are required!", 400
+
+        conn = get_db_connection()
+        cur = conn.cursor()
+        cur.execute("INSERT INTO students (name, room_number, faculty) VALUES (%s, %s, %s)", (name, room_number, faculty))
+        conn.commit()
+        cur.close()
+        conn.close()
+        return "<p>Student added successfully!</p><a href='/add'>Add another</a>"
+
+    # HTML form
+    return render_template_string("""
+        <h2>Add Student</h2>
+        <form method="post">
+            Name: <input name="name"><br>
+            Room Number: <input name="room_number"><br>
+            Faculty: <input name="faculty"><br>
+            <input type="submit" value="Add Student">
+        </form>
+    """)
+
+# View all students
+@app.route("/students", methods=["GET"])
+def get_students():
+    conn = get_db_connection()
+    cur = conn.cursor()
+    cur.execute("SELECT id, name, room_number, faculty FROM students")
+    rows = cur.fetchall()
+    cur.close()
+    conn.close()
+
+    return jsonify([
+        {"id": row[0], "name": row[1], "room_number": row[2], "faculty": row[3]} for row in rows
+    ])
+
+if __name__ == "__main__":
+    init_db()
+    app.run(host="0.0.0.0", port=8000)

z1/z2/app/requirements.txt

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+Flask==2.0.1
+Werkzeug==2.0.3
+psycopg2-binary==2.9.1
+python-dotenv==0.19.0
+Jinja2==3.0.3

z1/z2/k8s/deployment.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: flask-app
+  namespace: webapp-namespace
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: flask
+  template:
+    metadata:
+      labels:
+        app: flask
+    spec:
+      containers:
+      - name: flask
+        image: flask-app:latest
+        imagePullPolicy: Never
+        ports:
+        - containerPort: 8000
+        env:
+        - name: POSTGRES_HOST
+          value: postgres
+        - name: POSTGRES_DB
+          value: mydatabase
+        - name: POSTGRES_USER
+          value: myuser
+        - name: POSTGRES_PASSWORD
+          value: mypassword
+        - name: POSTGRES_PORT
+          value: "5432"

z1/z2/k8s/migrate-job.yaml

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+apiVersion: batch/v1
+kind: Job
+metadata:
+  name: migrate
+spec:
+  template:
+    spec:
+      containers:
+      - name: migrator
+        image: myapp:latest
+        command: ["python", "manage.py", "migrate"]
+      restartPolicy: Never

z1/z2/k8s/namespace.yaml

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+apiVersion: v1
+kind: Namespace
+metadata:
+  name: webapp-namespace

z1/z2/k8s/postgres-deployment.yaml

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+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: postgres-pvc
+  namespace: webapp-namespace
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: postgres
+  namespace: webapp-namespace
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: postgres
+  template:
+    metadata:
+      labels:
+        app: postgres
+    spec:
+      containers:
+      - name: postgres
+        image: postgres:13
+        env:
+        - name: POSTGRES_DB
+          value: mydatabase
+        - name: POSTGRES_USER
+          value: myuser
+        - name: POSTGRES_PASSWORD
+          value: mypassword
+        ports:
+        - containerPort: 5432
+        volumeMounts:
+        - name: postgres-storage
+          mountPath: /var/lib/postgresql/data
+      volumes:
+      - name: postgres-storage
+        persistentVolumeClaim:
+          claimName: postgres-pvc
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: postgres
+  namespace: webapp-namespace
+spec:
+  selector:
+    app: postgres
+  ports:
+  - port: 5432

z1/z2/k8s/service.yaml

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+apiVersion: v1
+kind: Service
+metadata:
+  name: flask-service
+  namespace: webapp-namespace
+spec:
+  selector:
+    app: flask
+  type: NodePort
+  ports:
+  - port: 8000
+    targetPort: 8000
+    nodePort: 30080  # <-- Changed this

z1/z2/prepare-app.sh

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+#!/bin/bash
+
+echo "Building Docker image for Flask app..."
+docker build -t flask-app:latest .
+
+echo "Creating Minikube image cache (if using Minikube)..."
+eval $(minikube docker-env)
+docker build -t flask-app:latest .
+
+echo "Preparation complete."

z1/z2/start-app.sh

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+#!/bin/bash
+
+echo "Creating Namespace..."
+kubectl apply -f k8s/namespace.yaml
+
+echo "Creating Persistent Volumes and StatefulSet..."
+kubectl apply -f k8s/statefulset.yaml -n webapp-namespace
+
+echo "Deploying PostgreSQL..."
+kubectl apply -f k8s/postgres-deployment.yaml -n webapp-namespace
+
+echo "Deploying Flask App..."
+kubectl apply -f k8s/deployment.yaml -n webapp-namespace
+
+echo "Creating Service..."
+kubectl apply -f k8s/service.yaml -n webapp-namespace
+
+echo "All resources have been applied."

z1/z2/stop-app.sh

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+#!/bin/bash
+
+echo "Deleting Flask App Deployment..."
+kubectl delete -f k8s/deployment.yaml -n webapp-namespace
+
+echo "Deleting Flask Service..."
+kubectl delete -f k8s/service.yaml -n webapp-namespace
+
+echo "Deleting PostgreSQL Deployment and PVC..."
+kubectl delete -f k8s/postgres-deployment.yaml -n webapp-namespace
+
+echo "Deleting StatefulSet and PVs..."
+kubectl delete -f k8s/statefulset.yaml -n webapp-namespace
+
+echo "Deleting Namespace..."
+kubectl delete -f k8s/namespace.yaml
+
+echo "All resources have been deleted."