Reload CustomResourceState Config File on Change

internal/wrapper.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"os"
 	"path/filepath"
-	"strings"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
@@ -30,67 +29,73 @@ import (
 	"k8s.io/klog/v2"
 
 	"k8s.io/kube-state-metrics/v2/pkg/app"
-	"k8s.io/kube-state-metrics/v2/pkg/customresource"
-	"k8s.io/kube-state-metrics/v2/pkg/customresourcestate"
 	"k8s.io/kube-state-metrics/v2/pkg/options"
 )
 
 // RunKubeStateMetricsWrapper is a wrapper around KSM, delegated to the root command.
 func RunKubeStateMetricsWrapper(opts *options.Options) {
-	var factories []customresource.RegistryFactory
-	if config, set := resolveCustomResourceConfig(opts); set {
-		crf, err := customresourcestate.FromConfig(config)
-		if err != nil {
-			klog.ErrorS(err, "Parsing from Custom Resource State Metrics file failed")
-			klog.FlushAndExit(klog.ExitFlushTimeout, 1)
-		}
-		factories = append(factories, crf...)
-	}
 
 	KSMRunOrDie := func(ctx context.Context) {
-		if err := app.RunKubeStateMetricsWrapper(ctx, opts, factories...); err != nil {
+		if err := app.RunKubeStateMetricsWrapper(ctx, opts); err != nil {
 			klog.ErrorS(err, "Failed to run kube-state-metrics")
 			klog.FlushAndExit(klog.ExitFlushTimeout, 1)
 		}
 	}
+
 	ctx, cancel := context.WithCancel(context.Background())
 	if file := options.GetConfigFile(*opts); file != "" {
-		viper.SetConfigType("yaml")
-		viper.SetConfigFile(file)
-		if err := viper.ReadInConfig(); err != nil {
+		cfgViper := viper.New()
+		cfgViper.SetConfigType("yaml")
+		cfgViper.SetConfigFile(file)
+		if err := cfgViper.ReadInConfig(); err != nil {
 			if errors.Is(err, viper.ConfigFileNotFoundError{}) {
 				klog.ErrorS(err, "Options configuration file not found", "file", file)
 			} else {
 				klog.ErrorS(err, "Error reading options configuration file", "file", file)
 			}
 			klog.FlushAndExit(klog.ExitFlushTimeout, 1)
 		}
-		viper.OnConfigChange(func(e fsnotify.Event) {
+		cfgViper.OnConfigChange(func(e fsnotify.Event) {
 			klog.Infof("Changes detected: %s\n", e.Name)
 			cancel()
 			// Wait for the ports to be released.
 			<-time.After(3 * time.Second)
 			ctx, cancel = context.WithCancel(context.Background())
 			go KSMRunOrDie(ctx)
 		})
-		viper.WatchConfig()
-	}
-	klog.Infoln("Starting kube-state-metrics")
-	KSMRunOrDie(ctx)
-	select {}
-}
+		cfgViper.WatchConfig()
 
-func resolveCustomResourceConfig(opts *options.Options) (customresourcestate.ConfigDecoder, bool) {
-	if s := opts.CustomResourceConfig; s != "" {
-		return yaml.NewDecoder(strings.NewReader(s)), true
-	}
-	if file := opts.CustomResourceConfigFile; file != "" {
-		f, err := os.Open(filepath.Clean(file))
+		// Merge configFile values with opts so we get the CustomResourceConfigFile from config as well
+		configFile, err := os.ReadFile(filepath.Clean(file))
 		if err != nil {
-			klog.ErrorS(err, "Custom Resource State Metrics file could not be opened")
+			klog.ErrorS(err, "failed to read options configuration file", "file", file)
+		}
+
+		yaml.Unmarshal(configFile, opts)
+	}
+	if opts.CustomResourceConfigFile != "" {
+		crcViper := viper.New()
+		crcViper.SetConfigType("yaml")
+		crcViper.SetConfigFile(opts.CustomResourceConfigFile)
+		if err := crcViper.ReadInConfig(); err != nil {
+			if errors.Is(err, viper.ConfigFileNotFoundError{}) {
+				klog.ErrorS(err, "Custom resource configuration file not found", "file", opts.CustomResourceConfigFile)
+			} else {
+				klog.ErrorS(err, "Error reading Custom resource configuration file", "file", opts.CustomResourceConfigFile)
+			}
 			klog.FlushAndExit(klog.ExitFlushTimeout, 1)
 		}
-		return yaml.NewDecoder(f), true
+		crcViper.OnConfigChange(func(e fsnotify.Event) {
+			klog.Infof("Changes detected: %s\n", e.Name)
+			cancel()
+			// Wait for the ports to be released.
+			<-time.After(3 * time.Second)
+			ctx, cancel = context.WithCancel(context.Background())
+			go KSMRunOrDie(ctx)
+		})
+		crcViper.WatchConfig()
 	}
-	return nil, false
+	klog.Infoln("Starting kube-state-metrics")
+	KSMRunOrDie(ctx)
+	select {}
 }

pkg/app/server.go

@@ -27,6 +27,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"time"
 
 	"gopkg.in/yaml.v3"
@@ -47,6 +48,7 @@ import (
 	"k8s.io/kube-state-metrics/v2/internal/store"
 	"k8s.io/kube-state-metrics/v2/pkg/allowdenylist"
 	"k8s.io/kube-state-metrics/v2/pkg/customresource"
+	"k8s.io/kube-state-metrics/v2/pkg/customresourcestate"
 	generator "k8s.io/kube-state-metrics/v2/pkg/metric_generator"
 	"k8s.io/kube-state-metrics/v2/pkg/metricshandler"
 	"k8s.io/kube-state-metrics/v2/pkg/optin"
@@ -73,8 +75,8 @@ func (pl promLogger) Log(v ...interface{}) error {
 }
 
 // RunKubeStateMetricsWrapper runs KSM with context cancellation.
-func RunKubeStateMetricsWrapper(ctx context.Context, opts *options.Options, factories ...customresource.RegistryFactory) error {
-	err := RunKubeStateMetrics(ctx, opts, factories...)
+func RunKubeStateMetricsWrapper(ctx context.Context, opts *options.Options) error {
+	err := RunKubeStateMetrics(ctx, opts)
 	if ctx.Err() == context.Canceled {
 		klog.Infoln("Restarting: kube-state-metrics, metrics will be reset")
 		return nil
@@ -85,11 +87,10 @@ func RunKubeStateMetricsWrapper(ctx context.Context, opts *options.Options, fact
 // RunKubeStateMetrics will build and run the kube-state-metrics.
 // Any out-of-tree custom resource metrics could be registered by newing a registry factory
 // which implements customresource.RegistryFactory and pass all factories into this function.
-func RunKubeStateMetrics(ctx context.Context, opts *options.Options, factories ...customresource.RegistryFactory) error {
+func RunKubeStateMetrics(ctx context.Context, opts *options.Options) error {
 	promLogger := promLogger{}
 
 	storeBuilder := store.NewBuilder()
-	storeBuilder.WithCustomResourceStoreFactories(factories...)
 
 	ksmMetricsRegistry := prometheus.NewRegistry()
 	ksmMetricsRegistry.MustRegister(version.NewCollector("kube_state_metrics"))
@@ -144,6 +145,22 @@ func RunKubeStateMetrics(ctx context.Context, opts *options.Options, factories .
 		}
 	}
 
+	// Loading custom resource state configuration from cli argument or config file
+	config, err := resolveCustomResourceConfig(opts)
+	if err != nil {
+		return err
+	}
+
+	var factories []customresource.RegistryFactory
+
+	if config != nil {
+		factories, err = customresourcestate.FromConfig(config)
+		if err != nil {
+			return fmt.Errorf("Parsing from Custom Resource State Metrics file failed: %v", err)
+		}
+	}
+	storeBuilder.WithCustomResourceStoreFactories(factories...)
+
 	if opts.CustomResourceConfigFile != "" {
 		crcFile, err := os.ReadFile(filepath.Clean(opts.CustomResourceConfigFile))
 		if err != nil {
@@ -156,24 +173,22 @@ func RunKubeStateMetrics(ctx context.Context, opts *options.Options, factories .
 
 	}
 
-	var resources []string
+	resources := make([]string, len(factories))
+
+	for i, factory := range factories {
+		resources[i] = factory.Name()
+	}
+
 	switch {
 	case len(opts.Resources) == 0 && !opts.CustomResourcesOnly:
+		resources = append(resources, options.DefaultResources.AsSlice()...)
 		klog.InfoS("Used default resources")
-		resources = options.DefaultResources.AsSlice()
-		// enable custom resource
-		for _, factory := range factories {
-			resources = append(resources, factory.Name())
-		}
 	case opts.CustomResourcesOnly:
 		// enable custom resource only
-		for _, factory := range factories {
-			resources = append(resources, factory.Name())
-		}
 		klog.InfoS("Used CRD resources only", "resources", resources)
 	default:
-		klog.InfoS("Used resources", "resources", opts.Resources.String())
-		resources = opts.Resources.AsSlice()
+		resources = append(resources, opts.Resources.AsSlice()...)
+		klog.InfoS("Used resources", "resources", resources)
 	}
 
 	if err := storeBuilder.WithEnabledResources(resources); err != nil {
@@ -419,3 +434,17 @@ func md5HashAsMetricValue(data []byte) float64 {
 	copy(bytes, smallSum)
 	return float64(binary.LittleEndian.Uint64(bytes))
 }
+
+func resolveCustomResourceConfig(opts *options.Options) (customresourcestate.ConfigDecoder, error) {
+	if s := opts.CustomResourceConfig; s != "" {
+		return yaml.NewDecoder(strings.NewReader(s)), nil
+	}
+	if file := opts.CustomResourceConfigFile; file != "" {
+		f, err := os.Open(filepath.Clean(file))
+		if err != nil {
+			return nil, fmt.Errorf("Custom Resource State Metrics file could not be opened: %v", err)
+		}
+		return yaml.NewDecoder(f), nil
+	}
+	return nil, nil
+}

tests/e2e/main_test.go

@@ -271,7 +271,7 @@ func TestDefaultCollectorMetricsAvailable(t *testing.T) {
 
 	files, err := os.ReadDir("../../internal/store/")
 	if err != nil {
-		t.Fatalf("failed to read dir to get all resouces name: %v", err)
+		t.Fatalf("failed to read dir to get all resources name: %v", err)
 	}
 
 	re := regexp.MustCompile(`^([a-z]+).go$`)