✨ Add helpers to configure logger options via pflags

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/onsi/gomega v1.8.1
 	github.com/prometheus/client_golang v1.0.0
 	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
-	go.uber.org/atomic v1.4.0 // indirect
+	github.com/spf13/pflag v1.0.5
 	go.uber.org/zap v1.10.0
 	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 // indirect
 	golang.org/x/sys v0.0.0-20190922100055-0a153f010e69 // indirect

go.sum

@@ -319,8 +319,6 @@ go.mongodb.org/mongo-driver v1.1.2/go.mod h1:u7ryQJ+DOzQmeO7zB6MHyr8jkEQvC8vH7qL
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.uber.org/atomic v1.3.2 h1:2Oa65PReHzfn29GpvgsYwloV9AVFHPDk8tYxt2c2tr4=
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
-go.uber.org/atomic v1.4.0 h1:cxzIVoETapQEqDhQu3QfnvXAV4AlzcvUCxkVUFw3+EU=
-go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/multierr v1.1.0 h1:HoEmRHQPVSqub6w2z2d2EOVs2fjyFRGyofhKuyDq0QI=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/zap v1.10.0 h1:ORx85nbTijNz8ljznvCMR1ZBIPKFn3jQrag10X2AsuM=

pkg/log/zap/flags.go

@@ -0,0 +1,140 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package zap contains helpers for setting up a new logr.Logger instance
+// using the Zap logging framework.
+package zap
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/spf13/pflag"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+var levelStrings = map[string]zapcore.Level{
+	"debug":  zap.DebugLevel,
+	"-1":     zap.DebugLevel,
+	"info":   zap.InfoLevel,
+	"0":      zap.InfoLevel,
+	"error":  zap.ErrorLevel,
+	"2":      zap.ErrorLevel,
+	"dpanic": zap.DPanicLevel,
+	"panic":  zap.PanicLevel,
+	"warn":   zap.WarnLevel,
+	"fatal":  zap.FatalLevel,
+}
+
+type encoderFlag struct {
+	setFunc func(zapcore.Encoder)
+	value   string
+}
+
+var _ pflag.Value = &encoderFlag{}
+
+func (ev *encoderFlag) String() string {
+	return ev.value
+}
+
+func (ev *encoderFlag) Type() string {
+	return "encoder"
+}
+
+func (ev *encoderFlag) Set(flagValue string) error {
+	val := strings.ToLower(flagValue)
+	switch val {
+	case "json":
+		ev.setFunc(newJSONEncoder())
+	case "console":
+		ev.setFunc(newConsoleEncoder())
+	default:
+		return fmt.Errorf("invalid encoder value \"%s\"", flagValue)
+	}
+	ev.value = flagValue
+	return nil
+}
+
+func newJSONEncoder() zapcore.Encoder {
+	encoderConfig := zap.NewProductionEncoderConfig()
+	return zapcore.NewJSONEncoder(encoderConfig)
+}
+
+func newConsoleEncoder() zapcore.Encoder {
+	encoderConfig := zap.NewDevelopmentEncoderConfig()
+	return zapcore.NewConsoleEncoder(encoderConfig)
+}
+
+type levelFlag struct {
+	setFunc func(zap.AtomicLevel)
+	value   string
+}
+
+var _ pflag.Value = &levelFlag{}
+
+func (ev *levelFlag) Set(flagValue string) error {
+	level, validLevel := levelStrings[strings.ToLower(flagValue)]
+	if !validLevel {
+		logLevel, err := strconv.Atoi(flagValue)
+		if err != nil {
+			return fmt.Errorf("invalid log level \"%s\"", flagValue)
+		}
+		if logLevel > 0 {
+			intLevel := -1 * logLevel
+			ev.setFunc(zap.NewAtomicLevelAt(zapcore.Level(int8(intLevel))))
+		} else {
+			return fmt.Errorf("invalid log level \"%s\"", flagValue)
+		}
+	}
+	ev.setFunc(zap.NewAtomicLevelAt(level))
+	ev.value = flagValue
+	return nil
+}
+
+func (ev *levelFlag) String() string {
+	return ev.value
+}
+
+func (ev *levelFlag) Type() string {
+	return "level"
+}
+
+type stackTraceFlag struct {
+	setFunc func(zap.AtomicLevel)
+	value   string
+}
+
+var _ pflag.Value = &stackTraceFlag{}
+
+func (ev *stackTraceFlag) Set(flagValue string) error {
+	level, validLevel := levelStrings[strings.ToLower(flagValue)]
+	if !validLevel {
+		return fmt.Errorf("invalid stacktrace level \"%s\"", flagValue)
+	}
+	ev.setFunc(zap.NewAtomicLevelAt(level))
+	ev.value = flagValue
+	return nil
+}
+
+func (ev *stackTraceFlag) String() string {
+	return ev.value
+}
+
+func (ev *stackTraceFlag) Type() string {
+	return "level"
+}

pkg/log/zap/zap.go

@@ -19,6 +19,7 @@ limitations under the License.
 package zap
 
 import (
+	"flag"
 	"io"
 	"os"
 	"time"
@@ -207,3 +208,53 @@ func NewRaw(opts ...Opts) *zap.Logger {
 	log = log.WithOptions(o.ZapOpts...)
 	return log
 }
+
+// BindFlags will parse the given flagset for zap option flags and set the log options accordingly
+//  zap-devel: Development Mode defaults(encoder=consoleEncoder,logLevel=Debug,stackTraceLevel=Warn)
+//			  Production Mode defaults(encoder=jsonEncoder,logLevel=Info,stackTraceLevel=Error)
+//  zap-encoder: Zap log encoding ('json' or 'console')
+//  zap-log-level:  Zap Level to configure the verbosity of logging. Can be one of 'debug', 'info', 'error',
+//			       or any integer value > 0 which corresponds to custom debug levels of increasing verbosity")
+//  zap-stacktrace-level: Zap Level at and above which stacktraces are captured (one of 'warn' or 'error')
+func (o *Options) BindFlags(fs *flag.FlagSet) {
+
+	// Set Development mode value
+	fs.BoolVar(&o.Development, "zap-devel", false,
+		"Development Mode defaults(encoder=consoleEncoder,logLevel=Debug,stackTraceLevel=Warn). "+
+			"Production Mode defaults(encoder=jsonEncoder,logLevel=Info,stackTraceLevel=Error)")
+
+	// Set Encoder value
+	var encVal encoderFlag
+	encVal.setFunc = func(fromFlag zapcore.Encoder) {
+		o.Encoder = fromFlag
+	}
+	fs.Var(&encVal, "zap-encoder", "Zap log encoding ('json' or 'console')")
+
+	// Set the Log Level
+	var levelVal levelFlag
+	levelVal.setFunc = func(fromFlag zap.AtomicLevel) {
+		o.Level = &fromFlag
+	}
+	fs.Var(&levelVal, "zap-log-level",
+		"Zap Level to configure the verbosity of logging. Can be one of 'debug', 'info', 'error', "+
+			"or any integer value > 0 which corresponds to custom debug levels of increasing verbosity")
+
+	// Set the StrackTrace Level
+	var stackVal stackTraceFlag
+	stackVal.setFunc = func(fromFlag zap.AtomicLevel) {
+		o.StacktraceLevel = &fromFlag
+	}
+	fs.Var(&stackVal, "zap-stacktrace-level",
+		"Zap Level at and above which stacktraces are captured (one of 'warn' or 'error')")
+}
+
+// UseFlagOptions configures the logger to use the Options set by parsing zap option flags from the CLI.
+//  opts := zap.Options{}
+//  opts.BindFlags(flag.CommandLine)
+//  log := zap.New(zap.UseFlagOptions(&opts))
+func UseFlagOptions(in *Options) Opts {
+	return func(o *Options) {
+		*o = *in
+		o.addDefaults()
+	}
+}