Container Logging: Dominando os Logs 📝

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║ CONTAINER LOGGING MATRIX                                  ║
║                                                          ║
║ stdout/stderr → driver → aggregator → storage → analysis ║
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║ STATUS: CAPTURING CONTAINER INSIGHTS...                  ║
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Logging Basics 🔰

Comandos Essenciais

# Logs básicos
docker logs container_id

# Follow logs em tempo real
docker logs -f container_id

# Logs com timestamp
docker logs -t container_id

# Últimas N linhas
docker logs --tail 100 container_id

# Logs desde timestamp
docker logs --since 2023-01-01T00:00:00 container_id

Log Drivers 🚗

Configuração de Driver

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}

Drivers Disponíveis

Driver	Uso	Descrição
json-file	Default	Logs em formato JSON
local	Local	Logs persistentes locais
syslog	System	Logs para syslog
journald	SystemD	Logs para journald
fluentd	Aggregation	Logs para Fluentd
splunk	Enterprise	Logs para Splunk

Advanced Logging 🎓

Fluentd Integration

version: '3'
services:
  app:
    logging:
      driver: fluentd
      options:
        fluentd-address: localhost:24224
        tag: docker.{{.Name}}

ELK Stack Setup

version: '3'
services:
  filebeat:
    image: elastic/filebeat
    volumes:
      - /var/lib/docker/containers:/var/lib/docker/containers:ro
      - /var/run/docker.sock:/var/run/docker.sock:ro

Logging Best Practices 🎯

DO's ✅

Configure log rotation
Use estruturado logging
Implemente log levels
Centralize logs
Monitore log size
Backup logs importantes

DON'Ts ❌

Não ignore log rotation
Evite logs verbosos demais
Não armazene dados sensíveis
Não negligencie log parsing
Evite duplicação de logs

Troubleshooting Matrix 🔍

Problema	Sintoma	Solução
Log cheio	Disk space	Configurar rotation
Log lento	Performance	Ajustar buffer size
Log perdido	Missing data	Verificar driver
Log duplicado	Redundancy	Checar configuração

Logging Patterns 📊

Structured Logging

{
  "level": "info",
  "timestamp": "2023-01-01T00:00:00Z",
  "service": "api",
  "message": "Request processed",
  "details": {
    "method": "GET",
    "path": "/api/v1/users",
    "duration": "125ms"
  }
}

Log Aggregation

┌──────────┐    ┌──────────┐    ┌──────────┐
│Container │───►│Collector │───►│  Store   │
└──────────┘    └──────────┘    └──────────┘
     │               │               │
     └───────────────┴───────────────┘
         Distributed Logging Flow

Waifu Logging Tips 💡

Monitoring Integration 📊

Prometheus Format

logging:
  metrics:
    - name: log_messages_total
      type: counter
      labels:
        level: ${level}
        service: ${service}

Grafana Dashboard

{
  "panels": [
    {
      "title": "Log Volume",
      "type": "graph",
      "targets": [
        {
          "expr": "rate(log_messages_total[5m])",
          "legendFormat": "{{level}}"
        }
      ]
    }
  ]
}

Quick Commands 🚀

# Debug logging
docker logs --debug container_id

# Export logs
docker logs container_id > app.log

# Multi-container logs
docker compose logs -f service_name

# Log stats
docker logs --details container_id

Checkpoint ✅

Você agora domina:

[x] Comandos básicos de logging
[x] Log drivers
[x] Log rotation
[x] Structured logging
[x] Log aggregation
[x] Troubleshooting
[x] Best practices

Próximos Passos 🎯

16 abril 2025