Enhance Flask-MySQL App with Docker, Kubernetes, Monitoring & Slack Integration

Dockerfile

@@ -1,5 +1,9 @@
-FROM ubuntu:20.04
-RUN apt-get update && apt-get install -y python3 python3-pip
-RUN pip3 install flask
-COPY app.py /opt/
-ENTRYPOINT FLASK_APP=/opt/app.py flask run --host=0.0.0.0 --port=8080
+FROM python:3.13-slim
+
+WORKDIR /app 
+
+COPY . .
+
+RUN pip3 install -r requirements.txt
+
+CMD [ "python", "app.py" ]

README.md

@@ -1,43 +1,97 @@
-# Simple Web Application
-
-This is a simple web application using [Python Flask](http://flask.pocoo.org/) and [MySQL](https://www.mysql.com/) database. 
-This is used in the demonstration of the development of Ansible Playbooks.
-
-  Below are the steps required to get this working on a base linux system.
-
-  - **Install all required dependencies**
-  - **Install and Configure Web Server**
-  - **Start Web Server**
-
-## 1. Install all required dependencies
-
-  Python and its dependencies
-  ```bash
-  apt-get install -y python3 python3-setuptools python3-dev build-essential python3-pip default-libmysqlclient-dev
-  ```
-
-## 2. Install and Configure Web Server
-
-Install Python Flask dependency
+
+# Simple Flask MySQL Web Application
+
+This is a simple Python Flask web application that connects to a MySQL database. It was originally built for demonstrating Ansible Playbook automation but has now been enhanced to support modern DevOps practices.
+
+---
+
+## 🚀 Features
+
+- Python Flask-based Web App
+- MySQL Database Integration
+- Docker Support
+- Kubernetes Manifests with HPA (Horizontal Pod Autoscaler)
+- Monitoring with Prometheus & Grafana
+- Slack Notification Integration
+
+---
+
+## 🛠️ Setup Instructions
+
+### 1. Install Required Dependencies (For Bare Metal)
+
+```bash
+apt-get install -y python3 python3-setuptools python3-dev build-essential python3-pip default-libmysqlclient-dev
+```
+
+### 2. Install Python Libraries
+
+```bash
+pip3 install flask flask-mysql
+```
+
+---
+
+## 🐳 Docker Support
+
+Build the Docker image:
+
 ```bash
-pip3 install flask
-pip3 install flask-mysql
+docker build -t flask-mysql-app:latest .
 ```
 
-- Copy `app.py` or download it from a source repository
-- Configure database credentials and parameters 
+Run the container:
 
-## 3. Start Web Server
+```bash
+docker run -p 5000:5000 flask-mysql-app:latest
+```
+
+---
+
+## ☸️ Kubernetes Deployment
+
+This project includes Kubernetes manifests for:
+
+- App Deployment & Service
+- MySQL Deployment & Service
+- HPA (Horizontal Pod Autoscaler)
+- Monitoring (Prometheus & Grafana)
+- Slack Alerts
+
+Apply manifests:
 
-Start web server
 ```bash
-FLASK_APP=app.py flask run --host=0.0.0.0
+kubectl apply -f k8s/
 ```
 
-## 4. Test
+---
+
+## 📊 Monitoring & Alerts
+
+- Prometheus scrapes metrics from Flask app and Kubernetes nodes.
+- Grafana dashboard is included.
+- Slack alerts configured via Alertmanager.
+
+---
+
+## 🧪 Testing the Application
+
+Open a browser and access:
 
-Open a browser and go to URL
 ```
 http://<IP>:5000                            => Welcome
 http://<IP>:5000/how%20are%20you            => I am good, how about you?
 ```
+
+---
+
+## 🤝 Contributing
+
+Feel free to fork the repo, raise PRs, and enhance it further.
+
+---
+
+## 📬 Stay Connected
+
+For contributions, feedback, or collaboration, connect with me on [LinkedIn](https://www.linkedin.com/in/aakash-sharma-8937b81aa/).
+

app.py

@@ -1,14 +1,29 @@
-import os
-from flask import Flask
+from flask import Flask, request
+from prometheus_flask_exporter import PrometheusMetrics
+from prometheus_client import Counter, generate_latest, CONTENT_TYPE_LATEST
+
 app = Flask(__name__)
 
+# ================= Prometheus Configs===================================================================
+http_requests_total = Counter('http_requests_total', 'Total HTTP Requests', ['method', 'endpoint'])
+
+@app.before_request
+def before_request():
+    http_requests_total.labels(method=request.method, endpoint=request.path).inc()
+
+@app.route('/metrics')
+def prometheus_metrics(): 
+    return generate_latest(), 200, {'Content-Type': CONTENT_TYPE_LATEST}
+
+# =========================================================================================================
+
 @app.route("/")
 def main():
     return "Welcome!"
 
-@app.route('/how are you')
+@app.route('/hru')
 def hello():
     return 'I am good, how about you?'
 
 if __name__ == "__main__":
-    app.run(host="0.0.0.0", port=8080)
+    app.run(host="0.0.0.0", port=8000)

k8s/application/deployment.yaml

@@ -0,0 +1,27 @@
+apiVersion: apps/v1
+kind: Deployment 
+metadata:
+  name: flask-app
+spec:
+  replicas: 2
+  selector:
+    matchLabels:
+      app: flask-app
+  template:
+    metadata:
+      labels:
+        app: flask-app
+    spec:
+      containers:
+        - name: flask-container
+          image: sharmaaakash170/flask-simple-app:latest
+          ports:
+            - containerPort: 8000
+          resources: 
+            requests:
+              cpu: "100m"
+              memory: "128Mi"
+            limits: 
+              cpu: "200m"
+              memory: "512Mi"
+

k8s/application/hpa.yaml

@@ -0,0 +1,18 @@
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: backend-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: flask-app
+  minReplicas: 1
+  maxReplicas: 5
+  metrics:
+  - type: Resource
+    resource:
+      name: cpu
+      target:
+        type: Utilization
+        averageUtilization: 50

k8s/application/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: flask-service
+spec:
+  selector:
+    app: flask-app
+  ports:
+    - protocol: TCP
+      port: 8000
+      targetPort: 8000

k8s/monitoring/grafana/deployment.yaml

@@ -0,0 +1,19 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: grafana
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: grafana
+  template:
+    metadata:
+      labels:
+        app: grafana
+    spec:
+      containers:
+      - name: grafana
+        image: grafana/grafana:10.4.0
+        ports:
+          - containerPort: 3000

k8s/monitoring/grafana/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: grafana-service
+spec:
+  selector:
+    app: grafana
+  ports:
+    - protocol: TCP
+      port: 3000
+      targetPort: 3000

k8s/monitoring/prometheus/deployment.yaml

@@ -0,0 +1,28 @@
+apiVersion: apps/v1 
+kind: Deployment 
+metadata: 
+  name: prometheus 
+spec: 
+  replicas: 1 
+  selector: 
+    matchLabels:
+      app: prometheus 
+  template: 
+    metadata:
+      labels:
+        app: prometheus
+    spec: 
+      containers:
+        - name: prometheus
+          image: prom/prometheus:v2.51.1
+          args:
+            - "--config.file=/etc/prometheus/prometheus.yml"
+          ports: 
+            - containerPort: 9090
+          volumeMounts:
+            - name: prometheus-config-volume
+              mountPath: /etc/prometheus/ 
+      volumes:
+        - name: prometheus-config-volume
+          configMap: 
+            name: prometheus-config

k8s/monitoring/prometheus/prometheus-config.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1 
+kind: ConfigMap 
+metadata:
+  name: prometheus-config 
+data:
+  prometheus.yml: |
+    global: 
+      scrape_interval: 15s
+    scrape_configs:
+      - job_name: 'flask-app'
+        static_configs: 
+          - targets: ['flask-service.default.svc.cluster.local:8000']

k8s/monitoring/prometheus/service.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1 
+kind: Service 
+metadata: 
+  name: prometheus-service
+spec: 
+  selector:
+    app: prometheus
+  ports: 
+    - port: 9090
+      targetPort: 9090
+  type: ClusterIP

requirements.txt

@@ -1 +1,3 @@
 Flask
+prometheus-flask-exporter
+prometheus_client