Docker

# Running containers
docker ps

# All containers (including stopped)
docker ps -a

# Custom format (more readable)
docker ps --format 'table {{.Names}}\t{{.Status}}\t{{.Ports}}'

# Stop gracefully (sends SIGTERM, waits 10s, then SIGKILL)
docker stop meu-nginx

# Stop immediately (SIGKILL direct — use only if necessary)
docker kill meu-nginx

# Start stopped container
docker start meu-nginx

# Restart
docker restart meu-nginx

# Remove stopped container
docker rm meu-nginx

# Force remove running container
docker rm -f meu-nginx

# Remove all stopped containers
docker container prune

# View all logs
docker logs meu-nginx

# Follow logs in real-time (like tail -f)
docker logs -f meu-nginx

# View only last 50 lines
docker logs --tail 50 meu-nginx

# Logs with timestamp
docker logs -t meu-nginx

# Open bash terminal in container
docker exec -it meu-nginx bash

# If image doesn't have bash, try sh
docker exec -it meu-nginx sh

# Execute single command without entering
docker exec meu-nginx ls /var/www/html

# Detailed container information (JSON)
docker inspect meu-nginx

# View CPU, memory and network usage in real-time
docker stats

# Stats for specific container
docker stats meu-nginx

# Create a volume manually
docker volume create dados-postgres

# List volumes
docker volume ls

# Inspect a volume (see physical location, etc)
docker volume inspect dados-postgres

# Use the volume in container
docker run -d \
  --name postgres \
  -v dados-postgres:/var/lib/postgresql/data \
  -e POSTGRES_PASSWORD=senha \
  postgres:15

# If you remove and recreate container, data persists!
docker rm -f postgres
docker run -d \
  --name postgres \
  -v dados-postgres:/var/lib/postgresql/data \
  -e POSTGRES_PASSWORD=senha \
  postgres:15
# Data is still there!

# Remove a volume (CAREFUL: deletes data!)
docker volume rm dados-postgres

# Remove unused volumes
docker volume prune

# Mount current folder inside container
docker run -d \
  --name app-dev \
  -p 3000:3000 \
  -v $(pwd):/app \
  -v /app/node_modules \
  node:20-alpine \
  sh -c 'npm install && npm run dev'

# What happened:
# -v $(pwd):/app          = current host folder mapped to /app in container
# -v /app/node_modules    = anonymous volume for node_modules (won't overwrite!)

# On Windows PowerShell, use ${PWD} instead of $(pwd)
docker run -v ${PWD}:/app ...

# ─────────────────────────────────────────────────────────────
# STAGE 1: Install dependencies
# ─────────────────────────────────────────────────────────────
FROM node:20-alpine AS dependencies

# Install native dependencies if necessary
# (bcrypt, sharp and others need build tools)
RUN apk add --no-cache python3 make g++

WORKDIR /app

# Copy ONLY dependency files first
# This leverages Docker cache:
# If package.json didn't change, this layer is reused
COPY package.json package-lock.json ./

# Install production dependencies
RUN npm ci --only=production


# ─────────────────────────────────────────────────────────────
# STAGE 2: Final image (smaller and more secure)
# ─────────────────────────────────────────────────────────────
FROM node:20-alpine

# Create non-root user to run application (security!)
RUN addgroup -S appgroup && adduser -S appuser -G appgroup

WORKDIR /app

# Copy node_modules from previous stage
COPY --from=dependencies /app/node_modules ./node_modules

# Copy application code
COPY . .

# Change file owner to created user
RUN chown -R appuser:appgroup /app

# Switch to non-root user
USER appuser

# Document port (good practice, not mandatory)
EXPOSE 3000

# Environment variables with default values
ENV NODE_ENV=production
ENV PORT=3000

# Check if application is healthy
HEALTHCHECK --interval=30s --timeout=5s --start-period=15s --retries=3 \
  CMD node -e "require('http').get('http://localhost:3000/health', (r) => process.exit(r.statusCode === 200 ? 0 : 1))"

# Start application
CMD ["node", "src/server.js"]

# Build image with tag 'minha-app:1.0'
docker build -t minha-app:1.0 .
# The dot (.) indicates Dockerfile is in current folder

# Use Dockerfile in different location
docker build -f caminho/Dockerfile -t minha-app .

# View layers and image size
docker history minha-app:1.0

# Login to Docker Hub
docker login

# Tag image with your Docker Hub username
docker tag minha-app:1.0 seuusuario/minha-app:1.0

# Push to Docker Hub
docker push seuusuario/minha-app:1.0

version: '3.8'

# ─── SERVICES ─────────────────────────────────────────────────
services:

  # Each service is a container
  nome-do-servico:
    image: imagem:tag          # OR
    build:                     # Build from Dockerfile
      context: .               # Folder with Dockerfile
      dockerfile: Dockerfile   # File name (if not 'Dockerfile')

    container_name: meu-app   # Fixed container name

    ports:
      - "HOST:CONTAINER"      # Port mapping

    environment:               # Environment variables
      - VARIAVEL=valor
      DATABASE_URL: postgres://user:senha@db/meudb

    env_file:                  # Or load from .env file
      - .env

    volumes:                   # Volumes and bind mounts
      - dados-nomeados:/var/dados
      - ./pasta-local:/app

    depends_on:               # Startup order
      db:                     # Wait for 'db' to be 'healthy'
        condition: service_healthy

    restart: unless-stopped   # Restart policy

    networks:                 # Networks to join
      - minha-rede

    healthcheck:              # Health check
      test: ["CMD", "curl", "-f", "http://localhost:3000/health"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s


# ─── NAMED VOLUMES ─────────────────────────────────────────
volumes:
  dados-nomeados:            # Volume managed by Docker
  outro-volume:
    external: true           # Externally created volume


# ─── NETWORKS ────────────────────────────────────────────────
networks:
  minha-rede:
    driver: bridge

# Start all services in background
docker compose up -d

# Start and rebuild images (when Dockerfile/code changed)
docker compose up -d --build

# Start only specific service
docker compose up -d nome-do-servico

# Stop containers (keeps volumes and networks)
docker compose stop

# Stop and REMOVE containers and networks (volumes remain)
docker compose down

# Remove everything including volumes (CAREFUL: deletes data!)
docker compose down -v

# List project containers
docker compose ps

# View logs from all services
docker compose logs

# Follow logs in real-time
docker compose logs -f

# Logs from specific service
docker compose logs -f app

# Open terminal in a service
docker compose exec app bash

# Execute one-off command
docker compose exec db psql -U usuario -d meudb

# Run one-off service (without starting others)
docker compose run --rm app npm test

# View final resolved configuration (variables substituted)
docker compose config

# Rebuild service without stopping others
docker compose up -d --build app

# Scale a service (create multiple instances)
docker compose up -d --scale app=3

version: '3.8'

services:

  # ─── APPLICATION ───────────────────────────────────────────────
  app:
    build:
      context: .
      dockerfile: Dockerfile
      target: production      # Multi-stage build stage
    ports:
      - "${PORT:-3000}:3000"
    environment:
      - NODE_ENV=production
      - DATABASE_URL=${DATABASE_URL}
      - REDIS_URL=${REDIS_URL}
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_healthy
    restart: unless-stopped
    networks:
      - app-net

  # ─── DATABASE ──────────────────────────────────────────
  db:
    image: postgres:15-alpine
    env_file: .env
    volumes:
      - postgres-data:/var/lib/postgresql/data
      - ./scripts/init.sql:/docker-entrypoint-initdb.d/init.sql
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U $${POSTGRES_USER} -d $${POSTGRES_DB}"]
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 30s
    networks:
      - app-net

  # ─── CACHE ───────────────────────────────────────────────────
  redis:
    image: redis:7-alpine
    command: redis-server --appendonly yes --maxmemory 256mb
    volumes:
      - redis-data:/data
    restart: unless-stopped
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 10s
      timeout: 5s
      retries: 5
    networks:
      - app-net

  # ─── REVERSE PROXY ───────────────────────────────────────────
  nginx:
    image: nginx:alpine
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - certbot-data:/etc/letsencrypt
    depends_on:
      - app
    restart: unless-stopped
    networks:
      - app-net

volumes:
  postgres-data:
  redis-data:
  certbot-data:

networks:
  app-net:
    driver: bridge

# docker-compose.override.yml
# This file is automatically merged with docker-compose.yml
# Use for development configs

version: '3.8'

services:
  app:
    build:
      target: development     # Use dev stage from Dockerfile
    volumes:
      - .:/app                # Bind mount for hot reload
      - /app/node_modules     # Preserve container's node_modules
    environment:
      - NODE_ENV=development
    command: npm run dev      # Override Dockerfile CMD

  db:
    ports:
      - "5432:5432"          # Expose port to connect externally

  redis:
    ports:
      - "6379:6379"