internal_logging.go raw

   1  // Copyright The OpenTelemetry Authors
   2  // SPDX-License-Identifier: Apache-2.0
   3  
   4  package global // import "go.opentelemetry.io/otel/internal/global"
   5  
   6  import (
   7  	"log"
   8  	"os"
   9  	"sync/atomic"
  10  
  11  	"github.com/go-logr/logr"
  12  	"github.com/go-logr/stdr"
  13  )
  14  
  15  // globalLogger holds a reference to the [logr.Logger] used within
  16  // go.opentelemetry.io/otel.
  17  //
  18  // The default logger uses stdr which is backed by the standard `log.Logger`
  19  // interface. This logger will only show messages at the Error Level.
  20  var globalLogger = func() *atomic.Pointer[logr.Logger] {
  21  	l := stdr.New(log.New(os.Stderr, "", log.LstdFlags|log.Lshortfile))
  22  
  23  	p := new(atomic.Pointer[logr.Logger])
  24  	p.Store(&l)
  25  	return p
  26  }()
  27  
  28  // SetLogger sets the global Logger to l.
  29  //
  30  // To see Warn messages use a logger with `l.V(1).Enabled() == true`
  31  // To see Info messages use a logger with `l.V(4).Enabled() == true`
  32  // To see Debug messages use a logger with `l.V(8).Enabled() == true`.
  33  func SetLogger(l logr.Logger) {
  34  	globalLogger.Store(&l)
  35  }
  36  
  37  // GetLogger returns the global logger.
  38  func GetLogger() logr.Logger {
  39  	return *globalLogger.Load()
  40  }
  41  
  42  // Info prints messages about the general state of the API or SDK.
  43  // This should usually be less than 5 messages a minute.
  44  func Info(msg string, keysAndValues ...any) {
  45  	GetLogger().V(4).Info(msg, keysAndValues...)
  46  }
  47  
  48  // Error prints messages about exceptional states of the API or SDK.
  49  func Error(err error, msg string, keysAndValues ...any) {
  50  	GetLogger().Error(err, msg, keysAndValues...)
  51  }
  52  
  53  // Debug prints messages about all internal changes in the API or SDK.
  54  func Debug(msg string, keysAndValues ...any) {
  55  	GetLogger().V(8).Info(msg, keysAndValues...)
  56  }
  57  
  58  // Warn prints messages about warnings in the API or SDK.
  59  // Not an error but is likely more important than an informational event.
  60  func Warn(msg string, keysAndValues ...any) {
  61  	GetLogger().V(1).Info(msg, keysAndValues...)
  62  }
  63