DevOps

Docker Basics: Complete Guide to Containerization

📅 December 05, 2025 ⏱️ 1 min read 👁️ 3 views 🏷️ DevOps

Docker makes it easy to create, deploy, and run applications in containers, ensuring consistency across environments.

Basic Dockerfile


FROM python:3.9

WORKDIR /app

COPY requirements.txt .
RUN pip install -r requirements.txt

COPY . .

CMD ["python", "app.py"]

Essential Docker Commands


# Build image
docker build -t myapp:latest .

# Run container
docker run -d -p 8000:8000 myapp:latest

# List containers
docker ps

# Stop container
docker stop container_id

# Remove container
docker rm container_id

Docker Compose


version: '3.8'

services:
  web:
    build: .
    ports:
      - "8000:8000"
    volumes:
      - .:/app
    environment:
      - DEBUG=1
  
  db:
    image: postgres:13
    environment:
      - POSTGRES_PASSWORD=secret

Best Practices


# Multi-stage build for smaller images
FROM python:3.9 AS builder
WORKDIR /app
COPY requirements.txt .
RUN pip install --user -r requirements.txt

FROM python:3.9-slim
WORKDIR /app
COPY --from=builder /root/.local /root/.local
COPY . .
CMD ["python", "app.py"]

Docker ensures your app runs the same everywhere!

🏷️ Tags:
docker devops containers deployment dockerfile

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