Uber Faster logger go.uber.org/zap

zap_example.go

// slower but easier & loosely typed interface
sugar := zap.NewExample().Sugar()
defer sugar.Sync()
sugar.Infow("failed to fetch URL",
  "url", "http://example.com",
  "attempt", 3,
  "backoff", time.Second,
)
sugar.Infof("failed to fetch URL: %s", "http://example.com")

// faster logging
logger := zap.NewExample()
defer logger.Sync()
logger.Info("failed to fetch URL",
  zap.String("url", "http://example.com"),
  zap.Int("attempt", 3),
  zap.Duration("backoff", time.Second),
)