# View logs
docker logs container-id

# Follow logs (live)
docker logs -f container-id

# Last 100 lines
docker logs --tail 100 container-id

# Timestamp logs
docker logs -t container-id

# Since/Until
docker logs --since 2024-01-01 container-id
docker logs --until 2024-01-31 container-id

# JSON file driver (default)
docker run --log-driver json-file myapp:1.0

# Syslog driver
docker run --log-driver syslog \
  --log-opt syslog-address=udp://localhost:514 \
  myapp:1.0

# Splunk driver
docker run --log-driver splunk \
  --log-opt splunk-token=$SPLUNK_TOKEN \
  --log-opt splunk-url=https://splunk-server:8088 \
  myapp:1.0

# Awslogs driver
docker run --log-driver awslogs \
  --log-opt awslogs-group=/ecs/myapp \
  --log-opt awslogs-region=us-east-1 \
  myapp:1.0

// Node.js example
const logger = {
  log: (level, message, meta = {}) => {
    console.log(
      JSON.stringify({
        timestamp: new Date().toISOString(),
        level,
        message,
        ...meta,
      })
    );
  },
};

logger.log("info", "Server started", { port: 3000 });
logger.log("error", "Database connection failed", { error: err.message });

version: "3.8"

services:
  app:
    build: .
    logging:
      driver: json-file
      options:
        max-size: "10m"
        max-file: "3"
        labels: "service=myapp"

  db:
    image: postgres:15-alpine
    logging:
      driver: json-file
      options:
        max-size: "10m"
        max-file: "3"

# Real-time resource usage
docker stats

# Specific container
docker stats mycontainer

# No-stream (snapshot)
docker stats --no-stream

# Format output
docker stats --format "table {{.Container}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.NetIO}}\t{{.BlockIO}}"

# Define health check
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD curl -f http://localhost:3000/health || exit 1

# Check health status
docker ps  # Shows health status
docker inspect mycontainer  # Shows detailed health info

# prometheus.yml
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: "docker"
    static_configs:
      - targets: ["localhost:9323"]

  - job_name: "containers"
    static_configs:
      - targets: ["localhost:9100"]

# Run Prometheus
docker run -d \
  -p 9090:9090 \
  -v $(pwd)/prometheus.yml:/etc/prometheus/prometheus.yml \
  prom/prometheus

# Run Node Exporter (for system metrics)
docker run -d \
  -p 9100:9100 \
  prom/node-exporter

version: "3.8"

services:
  elasticsearch:
    image: docker.elastic.co/elasticsearch/elasticsearch:8.0.0
    environment:
      - discovery.type=single-node
      - xpack.security.enabled=false
    ports:
      - "9200:9200"

  logstash:
    image: docker.elastic.co/logstash/logstash:8.0.0
    volumes:
      - ./logstash.conf:/usr/share/logstash/pipeline/logstash.conf
    ports:
      - "5000:5000"
    depends_on:
      - elasticsearch

  kibana:
    image: docker.elastic.co/kibana/kibana:8.0.0
    ports:
      - "5601:5601"
    depends_on:
      - elasticsearch

  app:
    build: .
    logging:
      driver: splunk
      options:
        splunk-token: ${SPLUNK_TOKEN}
        splunk-url: http://localhost:8088
    depends_on:
      - elasticsearch

# Run container with DataDog agent
docker run -d \
  -e DD_API_KEY=$DD_API_KEY \
  -e DD_SITE=datadoghq.com \
  -v /var/run/docker.sock:/var/run/docker.sock:ro \
  datadog/agent:latest

FROM node:18-alpine

# Install New Relic agent
RUN npm install newrelic

# Copy agent config
COPY newrelic.js ./

COPY . .

# Require agent first
CMD ["node", "-r", "newrelic", "app.js"]