Switch to go.uber.org/zap for JSON formatted logging

Signed-off-by: Monis Khan <mok@vmware.com>

internal/plog/level.go

@@ -4,18 +4,18 @@
 package plog
 
 import (
-	"strconv"
-
-	"k8s.io/component-base/logs"
+	"go.uber.org/zap/zapcore"
 	"k8s.io/klog/v2"
-
-	"go.pinniped.dev/internal/constable"
 )
 
 // LogLevel is an enum that controls verbosity of logs.
 // Valid values in order of increasing verbosity are leaving it unset, info, debug, trace and all.
 type LogLevel string
 
+func (l LogLevel) Enabled(_ zapcore.Level) bool {
+	return Enabled(l) // this basically says "log if the global plog level is l or greater"
+}
+
 const (
 	// LevelWarning (i.e. leaving the log level unset) maps to klog log level 0.
 	LevelWarning LogLevel = ""
@@ -27,33 +27,40 @@ const (
 	LevelTrace LogLevel = "trace"
 	// LevelAll maps to klog log level 100 (conceptually it is log level 8).
 	LevelAll LogLevel = "all"
-
-	errInvalidLogLevel = constable.Error("invalid log level, valid choices are the empty string, info, debug, trace and all")
 )
 
+var _ zapcore.LevelEnabler = LevelWarning
+
 const (
 	klogLevelWarning = iota * 2
-	klogLevelInfo
-	klogLevelDebug
-	klogLevelTrace
+	KlogLevelInfo
+	KlogLevelDebug
+	KlogLevelTrace
 	klogLevelAll
 )
 
-func ValidateAndSetLogLevelGlobally(level LogLevel) error {
-	klogLevel := klogLevelForPlogLevel(level)
-	if klogLevel < 0 {
-		return errInvalidLogLevel
-	}
-
-	if _, err := logs.GlogSetter(strconv.Itoa(int(klogLevel))); err != nil {
-		panic(err) // programmer error
-	}
-
-	return nil
-}
-
 // Enabled returns whether the provided plog level is enabled, i.e., whether print statements at the
 // provided level will show up.
 func Enabled(level LogLevel) bool {
-	return klog.V(klogLevelForPlogLevel(level)).Enabled()
+	l := klogLevelForPlogLevel(level)
+	// check that both our global level and the klog global level agree that the plog level is enabled
+	// klog levels are inverted when zap handles them
+	return globalLevel.Enabled(zapcore.Level(-l)) && klog.V(l).Enabled()
+}
+
+func klogLevelForPlogLevel(plogLevel LogLevel) klog.Level {
+	switch plogLevel {
+	case LevelWarning:
+		return klogLevelWarning // unset means minimal logs (Error and Warning)
+	case LevelInfo:
+		return KlogLevelInfo
+	case LevelDebug:
+		return KlogLevelDebug
+	case LevelTrace:
+		return KlogLevelTrace
+	case LevelAll:
+		return klogLevelAll + 100 // make all really mean all
+	default:
+		return -1
+	}
 }