varshithchand/flask-app repository overview

⁠🚀 Flask PostgreSQL Docker Setup (Updated)

This guide runs a Flask + PostgreSQL app using Docker (manual setup) with proper networking.

⁠🐳 1. Pull Required Images (Optional)

docker pull postgres:15
docker pull varshithchand/flask-app

⁠🌐 2. Create Docker Network

docker network create mynetwork

⁠🗄️ 3. Run PostgreSQL Container

docker run -d --name postgres_db --network mynetwork -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=password -e POSTGRES_DB=mydb -p 5432:5432 postgres:15

⁠🚀 4. Run Flask Application Container

docker run -d --name flask_app --network mynetwork -p 5000:5000 varshithchand/flask-app

⁠🌐 5. Access Application

Open in browser:

http://localhost:5000

⁠⚙️ Database Configuration (IMPORTANT)

Your Flask app must use:

postgresql://postgres:password@postgres_db:5432/mydb

⁠🧠 How It Works

• postgres_db → PostgreSQL container
• flask_app → Flask backend
• mynetwork → allows containers to communicate
• Flask connects to DB using container name

⁠🛑 Stop & Remove Containers

docker stop flask_app postgres_db
docker rm flask_app postgres_db

⁠🔥 Full Reset (Clean Everything)

docker rm -f flask_app postgres_db
docker volume prune -f
docker network rm mynetwork

⁠⚠️ Common Issues & Fixes

⁠❌ Container exits immediately

👉 Check logs:

docker logs flask_app

⁠❌ Database connection error

✔ Ensure:

• Correct hostname → postgres_db
• Same network → mynetwork

⁠❌ Port already in use

👉 Use different port:

docker run -d -p 5001:5000 ...

⁠🚀 Recommended Next Step (Better Approach)

Instead of manual setup, use:

docker-compose up --build

👉 Benefits:

• Auto networking
• Auto dependency handling
• Cleaner setup

⁠👨‍💻 Author

Varshith Chand Aspiring DevOps Engineer 🚀