json.go

Documentation: k8s.io/component-base/logs/json

     1  /*
     2  Copyright 2020 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package json
    18  
    19  import (
    20  	"io"
    21  	"sync/atomic"
    22  	"time"
    23  
    24  	"github.com/go-logr/logr"
    25  	"github.com/go-logr/zapr"
    26  	"go.uber.org/zap"
    27  	"go.uber.org/zap/zapcore"
    28  
    29  	"k8s.io/component-base/featuregate"
    30  	logsapi "k8s.io/component-base/logs/api/v1"
    31  )
    32  
    33  var (
    34  	// timeNow stubbed out for testing
    35  	timeNow = time.Now
    36  )
    37  
    38  type runtime struct {
    39  	v uint32
    40  }
    41  
    42  func (r *runtime) ZapV() zapcore.Level {
    43  	// zap levels are inverted: everything with a verbosity >= threshold gets logged.
    44  	return -zapcore.Level(atomic.LoadUint32(&r.v))
    45  }
    46  
    47  // Enabled implements the zapcore.LevelEnabler interface.
    48  func (r *runtime) Enabled(level zapcore.Level) bool {
    49  	return level >= r.ZapV()
    50  }
    51  
    52  func (r *runtime) SetVerbosityLevel(v uint32) error {
    53  	atomic.StoreUint32(&r.v, v)
    54  	return nil
    55  }
    56  
    57  var _ zapcore.LevelEnabler = &runtime{}
    58  
    59  // NewJSONLogger creates a new json logr.Logger and its associated
    60  // control interface. The separate error stream is optional and may be nil.
    61  // The encoder config is also optional.
    62  func NewJSONLogger(v logsapi.VerbosityLevel, infoStream, errorStream zapcore.WriteSyncer, encoderConfig *zapcore.EncoderConfig) (logr.Logger, logsapi.RuntimeControl) {
    63  	r := &runtime{v: uint32(v)}
    64  
    65  	if encoderConfig == nil {
    66  		encoderConfig = &zapcore.EncoderConfig{
    67  			MessageKey:     "msg",
    68  			CallerKey:      "caller",
    69  			NameKey:        "logger",
    70  			TimeKey:        "ts",
    71  			EncodeTime:     epochMillisTimeEncoder,
    72  			EncodeDuration: zapcore.StringDurationEncoder,
    73  			EncodeCaller:   zapcore.ShortCallerEncoder,
    74  		}
    75  	}
    76  
    77  	encoder := zapcore.NewJSONEncoder(*encoderConfig)
    78  	var core zapcore.Core
    79  	if errorStream == nil {
    80  		core = zapcore.NewCore(encoder, infoStream, r)
    81  	} else {
    82  		highPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
    83  			return lvl >= zapcore.ErrorLevel && r.Enabled(lvl)
    84  		})
    85  		lowPriority := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
    86  			return lvl < zapcore.ErrorLevel && r.Enabled(lvl)
    87  		})
    88  		core = zapcore.NewTee(
    89  			zapcore.NewCore(encoder, errorStream, highPriority),
    90  			zapcore.NewCore(encoder, infoStream, lowPriority),
    91  		)
    92  	}
    93  	l := zap.New(core, zap.WithCaller(true))
    94  	return zapr.NewLoggerWithOptions(l, zapr.LogInfoLevel("v"), zapr.ErrorKey("err")),
    95  		logsapi.RuntimeControl{
    96  			SetVerbosityLevel: r.SetVerbosityLevel,
    97  			Flush: func() {
    98  				_ = l.Sync()
    99  			},
   100  		}
   101  }
   102  
   103  func epochMillisTimeEncoder(_ time.Time, enc zapcore.PrimitiveArrayEncoder) {
   104  	nanos := timeNow().UnixNano()
   105  	millis := float64(nanos) / float64(time.Millisecond)
   106  	enc.AppendFloat64(millis)
   107  }
   108  
   109  // Factory produces JSON logger instances.
   110  type Factory struct{}
   111  
   112  var _ logsapi.LogFormatFactory = Factory{}
   113  
   114  func (f Factory) Feature() featuregate.Feature {
   115  	return logsapi.LoggingBetaOptions
   116  }
   117  
   118  func (f Factory) Create(c logsapi.LoggingConfiguration, o logsapi.LoggingOptions) (logr.Logger, logsapi.RuntimeControl) {
   119  	// We intentionally avoid all os.File.Sync calls. Output is unbuffered,
   120  	// therefore we don't need to flush, and calling the underlying fsync
   121  	// would just slow down writing.
   122  	//
   123  	// The assumption is that logging only needs to ensure that data gets
   124  	// written to the output stream before the process terminates, but
   125  	// doesn't need to worry about data not being written because of a
   126  	// system crash or powerloss.
   127  	stderr := zapcore.Lock(AddNopSync(o.ErrorStream))
   128  	if c.Options.JSON.SplitStream {
   129  		stdout := zapcore.Lock(AddNopSync(o.InfoStream))
   130  		size := c.Options.JSON.InfoBufferSize.Value()
   131  		if size > 0 {
   132  			// Prevent integer overflow.
   133  			if size > 2*1024*1024*1024 {
   134  				size = 2 * 1024 * 1024 * 1024
   135  			}
   136  			stdout = &zapcore.BufferedWriteSyncer{
   137  				WS:   stdout,
   138  				Size: int(size),
   139  			}
   140  		}
   141  		// stdout for info messages, stderr for errors.
   142  		return NewJSONLogger(c.Verbosity, stdout, stderr, nil)
   143  	}
   144  	// Write info messages and errors to stderr to prevent mixing with normal program output.
   145  	return NewJSONLogger(c.Verbosity, stderr, nil, nil)
   146  }
   147  
   148  // AddNoSync adds a NOP Sync implementation.
   149  func AddNopSync(writer io.Writer) zapcore.WriteSyncer {
   150  	return nopSync{Writer: writer}
   151  }
   152  
   153  type nopSync struct {
   154  	io.Writer
   155  }
   156  
   157  func (f nopSync) Sync() error {
   158  	return nil
   159  }
   160
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