Revert "logs: remove deprecated klog flags"

This reverts commit 2f762e4.

staging/src/k8s.io/component-base/cli/globalflag/globalflags_test.go

@@ -62,7 +62,7 @@ func TestAddGlobalFlags(t *testing.T) {
 	}{
 		{
 			// Happy case
-			expectedFlag:  []string{"help", "log-flush-frequency", "v", "vmodule"},
+			expectedFlag:  []string{"add-dir-header", "alsologtostderr", "help", "log-backtrace-at", "log-dir", "log-file", "log-file-max-size", "log-flush-frequency", "logtostderr", "one-output", "skip-headers", "skip-log-headers", "stderrthreshold", "v", "vmodule"},
 			matchExpected: false,
 		},
 		{

staging/src/k8s.io/component-base/logs/api/v1/options.go

@@ -20,6 +20,7 @@ import (
 	"flag"
 	"fmt"
 	"math"
+	"sort"
 	"strings"
 	"time"
 
@@ -31,7 +32,6 @@ import (
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/featuregate"
-	"k8s.io/component-base/logs/klogflags"
 )
 
 const (
@@ -183,8 +183,12 @@ func apply(c *LoggingConfiguration, featureGate featuregate.FeatureGate) error {
 
 // AddFlags adds command line flags for the configuration.
 func AddFlags(c *LoggingConfiguration, fs *pflag.FlagSet) {
+	// The help text is generated assuming that flags will eventually use
+	// hyphens, even if currently no normalization function is set for the
+	// flag set yet.
+	unsupportedFlags := strings.Join(unsupportedLoggingFlagNames(cliflag.WordSepNormalizeFunc), ", ")
 	formats := logRegistry.list()
-	fs.StringVar(&c.Format, "logging-format", c.Format, fmt.Sprintf("Sets the log format. Permitted formats: %s.", formats))
+	fs.StringVar(&c.Format, "logging-format", c.Format, fmt.Sprintf("Sets the log format. Permitted formats: %s.\nNon-default formats don't honor these flags: %s.\nNon-default choices are currently alpha and subject to change without warning.", formats, unsupportedFlags))
 	// No new log formats should be added after generation is of flag options
 	logRegistry.freeze()
 
@@ -232,13 +236,14 @@ var loggingFlags pflag.FlagSet
 
 func init() {
 	var fs flag.FlagSet
-	klogflags.Init(&fs)
+	klog.InitFlags(&fs)
 	loggingFlags.AddGoFlagSet(&fs)
 }
 
 // List of logs (k8s.io/klog + k8s.io/component-base/logs) flags supported by all logging formats
 var supportedLogsFlags = map[string]struct{}{
 	"v": {},
+	// TODO: support vmodule after 1.19 Alpha
 }
 
 // unsupportedLoggingFlags lists unsupported logging flags. The normalize
@@ -263,3 +268,15 @@ func unsupportedLoggingFlags(normalizeFunc func(f *pflag.FlagSet, name string) p
 	})
 	return allFlags
 }
+
+// unsupportedLoggingFlagNames lists unsupported logging flags by name, with
+// optional normalization and sorted.
+func unsupportedLoggingFlagNames(normalizeFunc func(f *pflag.FlagSet, name string) pflag.NormalizedName) []string {
+	unsupportedFlags := unsupportedLoggingFlags(normalizeFunc)
+	names := make([]string, 0, len(unsupportedFlags))
+	for _, f := range unsupportedFlags {
+		names = append(names, "--"+f.Name)
+	}
+	sort.Strings(names)
+	return names
+}

staging/src/k8s.io/component-base/logs/api/v1/options_test.go

@@ -39,7 +39,9 @@ func TestFlags(t *testing.T) {
 	fs.SetOutput(&output)
 	fs.PrintDefaults()
 	want := `      --log-flush-frequency duration   Maximum number of seconds between log flushes (default 5s)
-      --logging-format string          Sets the log format. Permitted formats: "text". (default "text")
+      --logging-format string          Sets the log format. Permitted formats: "text".
+                                       Non-default formats don't honor these flags: --add-dir-header, --alsologtostderr, --log-backtrace-at, --log-dir, --log-file, --log-file-max-size, --logtostderr, --one-output, --skip-headers, --skip-log-headers, --stderrthreshold, --vmodule.
+                                       Non-default choices are currently alpha and subject to change without warning. (default "text")
   -v, --v Level                        number for the log level verbosity
       --vmodule pattern=N,...          comma-separated list of pattern=N settings for file-filtered logging (only works for text log format)
 `

staging/src/k8s.io/component-base/logs/logs.go

@@ -27,11 +27,16 @@ import (
 
 	"github.com/spf13/pflag"
 	logsapi "k8s.io/component-base/logs/api/v1"
-	"k8s.io/component-base/logs/klogflags"
 	"k8s.io/klog/v2"
 )
 
-const vmoduleUsage = " (only works for the default text log format)"
+const deprecated = "will be removed in a future release, see https://github.com/kubernetes/enhancements/tree/master/keps/sig-instrumentation/2845-deprecate-klog-specific-flags-in-k8s-components"
+
+// TODO (https://github.com/kubernetes/kubernetes/issues/105310): once klog
+// flags are removed, stop warning about "Non-default formats don't honor these
+// flags" in config.go and instead add this remark here.
+//
+// const vmoduleUsage = " (only works for the default text log format)"
 
 var (
 	packageFlags = flag.NewFlagSet("logging", flag.ContinueOnError)
@@ -42,7 +47,7 @@ var (
 )
 
 func init() {
-	klogflags.Init(packageFlags)
+	klog.InitFlags(packageFlags)
 	packageFlags.DurationVar(&logFlushFreq, logsapi.LogFlushFreqFlagName, logsapi.LogFlushFreqDefault, "Maximum number of seconds between log flushes")
 }
 
@@ -76,29 +81,42 @@ var NewOptions = logsapi.NewLoggingConfiguration
 //
 // May be called more than once.
 func AddFlags(fs *pflag.FlagSet, opts ...Option) {
+	// Determine whether the flags are already present by looking up one
+	// which always should exist.
+	if fs.Lookup("logtostderr") != nil {
+		return
+	}
+
 	o := addFlagsOptions{}
 	for _, opt := range opts {
 		opt(&o)
 	}
 
-	// Add all supported flags.
+	// Add flags with pflag deprecation remark for some klog flags.
 	packageFlags.VisitAll(func(f *flag.Flag) {
 		pf := pflag.PFlagFromGoFlag(f)
 		switch f.Name {
-		case "v", logsapi.LogFlushFreqFlagName:
+		case "v":
+			// unchanged, potentially skip it
+			if o.skipLoggingConfigurationFlags {
+				return
+			}
+		case logsapi.LogFlushFreqFlagName:
 			// unchanged, potentially skip it
 			if o.skipLoggingConfigurationFlags {
 				return
 			}
 		case "vmodule":
+			// TODO: see above
+			// pf.Usage += vmoduleUsage
 			if o.skipLoggingConfigurationFlags {
 				return
 			}
-			pf.Usage += vmoduleUsage
-		}
-		if fs.Lookup(pf.Name) == nil {
-			fs.AddFlag(pf)
+		default:
+			// deprecated, but not hidden
+			pf.Deprecated = deprecated
 		}
+		fs.AddFlag(pf)
 	})
 }
 
@@ -119,16 +137,24 @@ func AddGoFlags(fs *flag.FlagSet, opts ...Option) {
 	packageFlags.VisitAll(func(f *flag.Flag) {
 		usage := f.Usage
 		switch f.Name {
-		case "v", logsapi.LogFlushFreqFlagName:
+		case "v":
+			// unchanged
+			if o.skipLoggingConfigurationFlags {
+				return
+			}
+		case logsapi.LogFlushFreqFlagName:
 			// unchanged
 			if o.skipLoggingConfigurationFlags {
 				return
 			}
 		case "vmodule":
+			// TODO: see above
+			// usage += vmoduleUsage
 			if o.skipLoggingConfigurationFlags {
 				return
 			}
-			usage += vmoduleUsage
+		default:
+			usage += " (DEPRECATED: " + deprecated + ")"
 		}
 		fs.Var(f.Value, f.Name, usage)
 	})

vendor/modules.txt

@@ -2223,7 +2223,6 @@ k8s.io/component-base/logs
 k8s.io/component-base/logs/api/v1
 k8s.io/component-base/logs/json
 k8s.io/component-base/logs/json/register
-k8s.io/component-base/logs/klogflags
 k8s.io/component-base/logs/logreduction
 k8s.io/component-base/logs/testinit
 k8s.io/component-base/metrics