nfd-master: add config file options for logging

cmd/nfd-master/main.go

@@ -20,6 +20,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"k8s.io/klog/v2"
@@ -40,8 +41,6 @@ func main() {
 	printVersion := flags.Bool("version", false, "Print version and exit.")
 
 	args, overrides := initFlags(flags)
-	// Inject klog flags
-	klog.InitFlags(flags)
 
 	_ = flags.Parse(os.Args[1:])
 	if len(flags.Args()) > 0 {
@@ -137,6 +136,8 @@ func initFlags(flagset *flag.FlagSet) (*master.Args, *master.ConfigOverrideArgs)
 	flagset.BoolVar(&args.EnableLeaderElection, "enable-leader-election", false,
 		"Enables a leader election. Enable this when running more than one replica on nfd master.")
 
+	initKlogFlags(flagset, args)
+
 	overrides := &master.ConfigOverrideArgs{
 		LabelWhiteList: &utils.RegexpVal{},
 		DenyLabelNs:    &utils.StringSetVal{},
@@ -165,3 +166,24 @@ func initFlags(flagset *flag.FlagSet) (*master.Args, *master.ConfigOverrideArgs)
 
 	return args, overrides
 }
+
+func initKlogFlags(flagset *flag.FlagSet, args *master.Args) {
+	args.Klog = make(map[string]*utils.KlogFlagVal)
+
+	flags := flag.NewFlagSet("klog flags", flag.ContinueOnError)
+	//flags.SetOutput(ioutil.Discard)
+	klog.InitFlags(flags)
+	flags.VisitAll(func(f *flag.Flag) {
+		name := klogConfigOptName(f.Name)
+		args.Klog[name] = utils.NewKlogFlagVal(f)
+		flagset.Var(args.Klog[name], f.Name, f.Usage)
+	})
+}
+
+func klogConfigOptName(flagName string) string {
+	split := strings.Split(flagName, "_")
+	for i, v := range split[1:] {
+		split[i+1] = strings.ToUpper(v[0:1]) + v[1:]
+	}
+	return strings.Join(split, "")
+}

cmd/nfd-master/main_test.go

@@ -0,0 +1,39 @@
+/*
+Copyright 2023 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 main
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestKlogConfigOptName(t *testing.T) {
+	Convey("When converting names of klog command line flags", t, func() {
+		tcs := map[string]string{
+			"":                    "",
+			"a":                   "a",
+			"an_arg":              "anArg",
+			"arg_with_many_parts": "argWithManyParts",
+		}
+		Convey("resulting config option names should be as expected", func() {
+			for input, expected := range tcs {
+				So(klogConfigOptName(input), ShouldEqual, expected)
+			}
+		})
+	})
+}

deployment/components/master-config/nfd-master.conf.example

@@ -5,6 +5,21 @@
 # enableTaints: false
 # labelWhiteList: "foo"
 # resyncPeriod: "2h"
+# klog:
+#    addDirHeader: false
+#    alsologtostderr: false
+#    logBacktraceAt:
+#    logtostderr: true
+#    skipHeaders: false
+#    stderrthreshold: 2
+#    v: 0
+#    vmodule:
+##   NOTE: the following options are not dynamically run-time configurable
+##         and require a nfd-master restart to take effect after being changed
+#    logDir:
+#    logFile:
+#    logFileMaxSize: 1800
+#    skipLogHeaders: false
 # leaderElection:
 #   leaseDuration: 15s
 #   # this value has to be lower than leaseDuration and greater than retryPeriod*1.2

deployment/helm/node-feature-discovery/values.yaml

@@ -21,6 +21,21 @@ master:
     # enableTaints: false
     # labelWhiteList: "foo"
     # resyncPeriod: "2h"
+    # klog:
+    #    addDirHeader: false
+    #    alsologtostderr: false
+    #    logBacktraceAt:
+    #    logtostderr: true
+    #    skipHeaders: false
+    #    stderrthreshold: 2
+    #    v: 0
+    #    vmodule:
+    ##   NOTE: the following options are not dynamically run-time configurable
+    ##         and require a nfd-master restart to take effect after being changed
+    #    logDir:
+    #    logFile:
+    #    logFileMaxSize: 1800
+    #    skipLogHeaders: false
     # leaderElection:
     #   leaseDuration: 15s
     #   # this value has to be lower than leaseDuration and greater than retryPeriod*1.2

docs/reference/master-configuration-reference.md

@@ -191,7 +191,7 @@ leaderElection:
   retryPeriod: 2s
 ```
 
-### nfdApiParallelism
+## nfdApiParallelism
 
 The `nfdApiParallelism` option can be used to specify the maximum
 number of concurrent node updates.
@@ -205,3 +205,106 @@ Example:
 ```yaml
 nfdApiParallelism: 1
 ```
+
+## klog
+
+The following options specify the logger configuration. Most of which can be
+dynamically adjusted at run-time.
+
+> **NOTE:** The logger options can also be specified via command line flags
+> which take precedence over any corresponding config file options.
+
+### klog.addDirHeader
+
+If true, adds the file directory to the header of the log messages.
+
+Default: `false`
+
+Run-time configurable: yes
+
+### klog.alsologtostderr
+
+Log to standard error as well as files.
+
+Default: `false`
+
+Run-time configurable: yes
+
+### klog.logBacktraceAt
+
+When logging hits line file:N, emit a stack trace.
+
+Default: *empty*
+
+Run-time configurable: yes
+
+### klog.logDir
+
+If non-empty, write log files in this directory.
+
+Default: *empty*
+
+Run-time configurable: no
+
+### klog.logFile
+
+If non-empty, use this log file.
+
+Default: *empty*
+
+Run-time configurable: no
+
+### klog.logFileMaxSize
+
+Defines the maximum size a log file can grow to. Unit is megabytes. If the
+value is 0, the maximum file size is unlimited.
+
+Default: `1800`
+
+Run-time configurable: no
+
+### klog.logtostderr
+
+Log to standard error instead of files
+
+Default: `true`
+
+Run-time configurable: yes
+
+### klog.skipHeaders
+
+If true, avoid header prefixes in the log messages.
+
+Default: `false`
+
+Run-time configurable: yes
+
+### klog.skipLogHeaders
+
+If true, avoid headers when opening log files.
+
+Default: `false`
+
+Run-time configurable: no
+
+### klog.stderrthreshold
+
+Logs at or above this threshold go to stderr (default 2)
+
+Run-time configurable: yes
+
+### klog.v
+
+Number for the log level verbosity.
+
+Default: `0`
+
+Run-time configurable: yes
+
+### klog.vmodule
+
+Comma-separated list of `pattern=N` settings for file-filtered logging.
+
+Default: *empty*
+
+Run-time configurable: yes

pkg/nfd-master/nfd-master.go

@@ -78,6 +78,7 @@ type NFDConfig struct {
 	ResyncPeriod      utils.DurationVal
 	LeaderElection    LeaderElectionConfig
 	NfdApiParallelism int
+	Klog              map[string]string
 }
 
 // LeaderElectionConfig contains the configuration for leader election
@@ -106,6 +107,7 @@ type Args struct {
 	ConfigFile           string
 	Instance             string
 	KeyFile              string
+	Klog                 map[string]*utils.KlogFlagVal
 	Kubeconfig           string
 	CrdController        bool
 	EnableNodeFeatureApi bool
@@ -201,6 +203,7 @@ func newDefaultConfig() *NFDConfig {
 			RetryPeriod:   utils.DurationVal{Duration: time.Duration(2) * time.Second},
 			RenewDeadline: utils.DurationVal{Duration: time.Duration(10) * time.Second},
 		},
+		Klog: make(map[string]string),
 	}
 }
 
@@ -1166,6 +1169,28 @@ func (m *nfdMaster) createExtendedResourcePatches(n *corev1.Node, extendedResour
 	return patches
 }
 
+func (m *nfdMaster) configureKlog(c *NFDConfig) error {
+	// Handle klog
+	for k, a := range m.args.Klog {
+		if !a.IsSetFromCmdline() {
+			v, ok := c.Klog[k]
+			if !ok {
+				v = a.DefValue()
+			}
+			if err := a.SetFromConfig(v); err != nil {
+				return fmt.Errorf("failed to set logger option klog.%s = %v: %v", k, v, err)
+			}
+		}
+	}
+	for k := range c.Klog {
+		if _, ok := m.args.Klog[k]; !ok {
+			klog.InfoS("unknown logger option in config", "optionName", k)
+		}
+	}
+
+	return nil
+}
+
 // Parse configuration options
 func (m *nfdMaster) configure(filepath string, overrides string) error {
 	// Create a new default config
@@ -1224,6 +1249,11 @@ func (m *nfdMaster) configure(filepath string, overrides string) error {
 	}
 
 	m.config = c
+
+	if err := m.configureKlog(c); err != nil {
+		return err
+	}
+
 	if !c.NoPublish {
 		kubeconfig, err := m.getKubeconfig()
 		if err != nil {