Dockerized Flask app: added Docker setup and updated README

.dockerignore

@@ -0,0 +1,9 @@
+__pycache__/
+*.pyc
+*.pyo
+*.pyd
+*.db
+*.sqlite3
+.env
+.git
+.gitignore

Dockerfile

@@ -0,0 +1,20 @@
+# Use official lightweight Python image
+FROM python:3.10-slim
+
+# Set working directory
+WORKDIR /app
+
+# Copy requirements first (for caching)
+COPY requirements.txt .
+
+# Install dependencies
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy all project files
+COPY . .
+
+# Expose Flask default port
+EXPOSE 5000
+
+# Run the Flask app
+CMD ["python", "app.py"]

README.md

@@ -29,6 +29,55 @@ For more basic knowledge of Flask, you can refer to [a tutorial on Tutorialspoin
 
 - Step 3: Go to this app's directory and run `python app.py`
 
+## How to Run (Docker way)
+This app has been containerized using Docker. You can run it easily on any machine without worrying about dependencies.
+## Prerequisites for Docker
+
+Before running the app using Docker, make sure you have the following installed:
+
+1. **Git** – to clone or fork the repository  
+   - [Download Git](https://git-scm.com/downloads)
+
+2. **Docker** – to build and run containers  
+   - [Download Docker](https://www.docker.com/get-started)
+
+3. **Docker Compose** – to run multi-container apps (usually comes with Docker Desktop)  
+   - [Install Docker Compose](https://docs.docker.com/compose/install/)
+
+### Steps to Run the App
+
+1. **Clone or fork the repository:**
+```bash
+git clone https://github.com/your-username/your-repo.git
+
+cd your-repo
+```
+
+2. **Build and start containers:**
+```bash
+docker-compose up -d
+```
+3. **Check running containers:**
+```bash
+docker ps
+```
+4. **Open the app in your browser:**
+[runs on localhost:5000](http://localhost:5000)
+
+5. **Stop containers:**
+```bash
+docker-compose down
+```
+
+## Benefits:
+
+-Easy setup: No need to install Python or dependencies manually.
+
+-Consistency: Same behavior across all environments (dev, staging, production).
+
+-Portability: Can run anywhere Docker is available.
+
+-Isolation: Dependencies are separated from the host machine.
 
 
 ## Details about This Toy App

docker-compose.yml

@@ -0,0 +1,11 @@
+
+services:
+  web:
+    build: .
+    container_name: flask-example
+    ports:
+      - "5000:5000"
+    volumes:
+      - .:/app
+    environment:
+      - FLASK_ENV=development

requirements.txt

@@ -1,3 +1,4 @@
-Flask==1.1.2
-Werkzeug==1.0.1
-markupsafe==2.0.1
+Flask==2.2.5
+Werkzeug==2.2.3
+markupsafe==2.1.1
+Jinja2==3.1.2