Docker Containerization

Build and manage Docker containers for development and deployment.

Image Management

# Build image from Dockerfile
docker build -t myapp:latest .

# Build with build arguments
docker build --build-arg VERSION=1.0 -t myapp:1.0 .

# List images
docker images

# Remove image
docker rmi myapp:latest

Container Operations

# Run container interactively
docker run -it ubuntu:22.04 /bin/bash

# Run detached with port mapping
docker run -d -p 8080:80 --name webserver nginx

# Run with volume mount
docker run -v /host/path:/container/path myapp

# Run with environment variables
docker run -e DATABASE_URL=postgres://... myapp

Dockerfile Best Practices

FROM ubuntu:22.04

# Install dependencies in single layer
RUN apt-get update && apt-get install -y \
    build-essential \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy only necessary files
COPY requirements.txt .
RUN pip install -r requirements.txt

COPY src/ /app/src/

WORKDIR /app
CMD ["python", "src/main.py"]

Multi-Architecture Builds

# Create builder for multi-arch
docker buildx create --use --name multiarch

# Build for ARM and x86
docker buildx build --platform linux/amd64,linux/arm64 \
  -t myapp:latest --push .

Container Networking

# Create network
docker network create mynet

# Run containers on network
docker run -d --network mynet --name db postgres
docker run -d --network mynet --name app myapp

Docker Compose

version: '3.8'
services:
  web:
    build: .
    ports:
      - "8080:80"
    volumes:
      - ./data:/app/data
    environment:
      - DEBUG=true