internal/plog: add Enabled()

Signed-off-by: Andrew Keesler <akeesler@vmware.com>

internal/plog/klog.go

@@ -1,4 +1,4 @@
-// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package plog
@@ -7,6 +7,7 @@ import (
 	"sync"
 
 	"github.com/spf13/pflag"
+	"k8s.io/klog/v2"
 )
 
 //nolint: gochecknoglobals
@@ -30,3 +31,34 @@ func RemoveKlogGlobalFlags() {
 		panic("unsupported global klog flag set")
 	}
 }
+
+func klogLevelForPlogLevel(plogLevel LogLevel) (klogLevel klog.Level) {
+	switch plogLevel {
+	case LevelWarning:
+		klogLevel = klogLevelWarning // unset means minimal logs (Error and Warning)
+	case LevelInfo:
+		klogLevel = klogLevelInfo
+	case LevelDebug:
+		klogLevel = klogLevelDebug
+	case LevelTrace:
+		klogLevel = klogLevelTrace
+	case LevelAll:
+		klogLevel = klogLevelAll + 100 // make all really mean all
+	default:
+		klogLevel = -1
+	}
+
+	return
+}
+
+func getKlogLevel() klog.Level {
+	// hack around klog not exposing a Get method
+	for i := klog.Level(0); i < 256; i++ {
+		if klog.V(i).Enabled() {
+			continue
+		}
+		return i - 1
+	}
+
+	return -1
+}

internal/plog/level.go

@@ -1,4 +1,4 @@
-// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package plog
@@ -39,26 +39,20 @@ const (
 )
 
 func ValidateAndSetLogLevelGlobally(level LogLevel) error {
-	var klogLogLevel int
-
-	switch level {
-	case LevelWarning:
-		klogLogLevel = klogLevelWarning // unset means minimal logs (Error and Warning)
-	case LevelInfo:
-		klogLogLevel = klogLevelInfo
-	case LevelDebug:
-		klogLogLevel = klogLevelDebug
-	case LevelTrace:
-		klogLogLevel = klogLevelTrace
-	case LevelAll:
-		klogLogLevel = klogLevelAll + 100 // make all really mean all
-	default:
+	klogLevel := klogLevelForPlogLevel(level)
+	if klogLevel < 0 {
 		return errInvalidLogLevel
 	}
 
-	if _, err := logs.GlogSetter(strconv.Itoa(klogLogLevel)); err != nil {
+	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 getKlogLevel() >= klogLevelForPlogLevel(level)
+}

internal/plog/level_test.go

@@ -1,4 +1,4 @@
-// Copyright 2020 the Pinniped contributors. All Rights Reserved.
+// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
 package plog
@@ -13,42 +13,50 @@ import (
 )
 
 func TestValidateAndSetLogLevelGlobally(t *testing.T) {
-	originalLogLevel := getKlogLevel(t)
+	originalLogLevel := getKlogLevel()
+	require.GreaterOrEqual(t, int(originalLogLevel), int(klog.Level(0)), "cannot get klog level")
 
 	tests := []struct {
 		name        string
 		level       LogLevel
 		wantLevel   klog.Level
+		wantEnabled []LogLevel
 		wantErr     string
 	}{
 		{
 			name:        "unset",
 			wantLevel:   0,
+			wantEnabled: []LogLevel{LevelWarning},
 		},
 		{
 			name:        "warning",
 			level:       LevelWarning,
 			wantLevel:   0,
+			wantEnabled: []LogLevel{LevelWarning},
 		},
 		{
 			name:        "info",
 			level:       LevelInfo,
 			wantLevel:   2,
+			wantEnabled: []LogLevel{LevelWarning, LevelInfo},
 		},
 		{
 			name:        "debug",
 			level:       LevelDebug,
 			wantLevel:   4,
+			wantEnabled: []LogLevel{LevelWarning, LevelInfo, LevelDebug},
 		},
 		{
 			name:        "trace",
 			level:       LevelTrace,
 			wantLevel:   6,
+			wantEnabled: []LogLevel{LevelWarning, LevelInfo, LevelDebug, LevelTrace},
 		},
 		{
 			name:        "all",
 			level:       LevelAll,
 			wantLevel:   108,
+			wantEnabled: []LogLevel{LevelWarning, LevelInfo, LevelDebug, LevelTrace, LevelAll},
 		},
 		{
 			name:      "invalid level",
@@ -66,26 +74,31 @@ func TestValidateAndSetLogLevelGlobally(t *testing.T) {
 
 			err := ValidateAndSetLogLevelGlobally(tt.level)
 			require.Equal(t, tt.wantErr, errString(err))
-			require.Equal(t, tt.wantLevel, getKlogLevel(t))
+			require.Equal(t, tt.wantLevel, getKlogLevel())
+
+			if tt.wantEnabled != nil {
+				allLevels := []LogLevel{LevelWarning, LevelInfo, LevelDebug, LevelTrace, LevelAll}
+				for _, level := range allLevels {
+					if contains(tt.wantEnabled, level) {
+						require.Truef(t, Enabled(level), "wanted %q to be enabled", level)
+					} else {
+						require.False(t, Enabled(level), "did not want %q to be enabled", level)
+					}
+				}
+			}
 		})
 	}
 
-	require.Equal(t, originalLogLevel, getKlogLevel(t))
+	require.Equal(t, originalLogLevel, getKlogLevel())
 }
 
-func getKlogLevel(t *testing.T) klog.Level {
-	t.Helper()
-
-	// hack around klog not exposing a Get method
-	for i := klog.Level(0); i < 256; i++ {
-		if klog.V(i).Enabled() {
-			continue
+func contains(haystack []LogLevel, needle LogLevel) bool {
+	for _, hay := range haystack {
+		if hay == needle {
+			return true
 		}
-		return i - 1
 	}
-
-	t.Fatal("unknown log level")
-	return 0
+	return false
 }
 
 func errString(err error) string {