name: docker-deployment description: Help with Docker containerization and deployment tasks. Use when working with Dockerfiles, docker-compose files, container builds, or when the user asks about Docker deployment.

Docker Deployment

Assist with Docker containerization, image building, and deployment workflows.

Quick Start

When helping with Docker tasks:

1. Identify the task type (build, run, compose, debug)
2. Review existing Docker configuration
3. Implement changes following best practices
4. Test the configuration

Dockerfile Best Practices

Multi-Stage Builds

Use multi-stage builds to minimize image size:

# Build stage
FROM python:3.11-slim as builder
WORKDIR /app
COPY requirements.txt .
RUN pip install --user -r requirements.txt

# Production stage
FROM python:3.11-slim
WORKDIR /app
COPY --from=builder /root/.local /root/.local
COPY . .
ENV PATH=/root/.local/bin:$PATH
CMD ["python", "main.py"]

Layer Optimization

• Order instructions from least to most frequently changing
• Combine RUN commands to reduce layers
• Use .dockerignore to exclude unnecessary files

Security

• Use specific image tags (not latest)
• Run as non-root user when possible
• Scan images for vulnerabilities
• Don't include secrets in images

Docker Compose Patterns

Development Setup

services:
  app:
    build: .
    volumes:
      - .:/app  # Mount for hot reload
    environment:
      - DEBUG=true
    ports:
      - "8000:8000"

Production Setup

services:
  app:
    image: myapp:${VERSION:-latest}
    restart: unless-stopped
    environment:
      - DEBUG=false
    deploy:
      resources:
        limits:
          memory: 512M

Common Tasks

Build and Run

# Build image
docker build -t myapp:latest .

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

# View logs
docker logs -f container_name

Compose Commands

# Start services
docker-compose up -d

# Rebuild and start
docker-compose up -d --build

# View logs
docker-compose logs -f

# Stop and remove
docker-compose down

Debugging

# Shell into running container
docker exec -it container_name /bin/bash

# Inspect container
docker inspect container_name

# Check resource usage
docker stats

Troubleshooting Checklist

• Port conflicts resolved
• Volume mounts have correct permissions
• Environment variables are set
• Network connectivity between services
• Sufficient disk space for images
• Memory limits appropriate for workload