Flask + PostgreSQL

Two-service compose stack — Flask API with PostgreSQL database (mid-point project pattern)

📋Configuration Files

docker-compose.yaml

PostgreSQL database + Flask app with env file and volume persistence

yaml

1version: "3.9"
2 
3services:
4  db:
5    image: postgres:15-alpine
6    environment:
7      POSTGRES_DB: dukaan_db
8      POSTGRES_USER: dukaan
9      POSTGRES_PASSWORD: dukaan123
10    ports:
11      - "5432:5432"
12    volumes:
13      - pgdata:/var/lib/postgresql/data
14 
15  app:
16    build: .
17    ports:
18      - "5000:5000"
19    env_file:
20      - .env
21    depends_on:
22      - db
23 
24volumes:
25  pgdata:

Dockerfile

Flask application container image

dockerfile

1FROM python:3.12-slim
2WORKDIR /app
3COPY requirements.txt .
4RUN pip install --no-cache-dir -r requirements.txt
5COPY . .
6EXPOSE 5000
7CMD ["python", "app.py"]

Docker Compose → K8s: minimal vs production

What to add before production merge

Aspect	Minimal	Production
Networking	compose default bridge	ClusterIP + Ingress; no hostNetwork in prod
Secrets	env in compose file	K8s Secret + External Secrets; never plain YAML in git
Volumes	bind mount ./data	PVC + backup strategy; StatefulSet for DB
Scaling	replicas: 1 in compose	Deployment replicas + HPA; PDB for HA
Health	no healthcheck	readiness + liveness probes before Service traffic
Image	build: . locally	pinned image from registry; CI builds digest

📄

Step 01

Run with Docker Compose

(01)Build and start services

Linux

1cd your-project/
2docker compose up -d --build
3docker compose ps
4docker compose logs -f app

(02)Stop and clean up

Linux

1docker compose down
2docker compose down -v  # remove volumes