fix errors

Author: rashmichandrashekar

internal/wrapper.go

@@ -89,7 +89,7 @@ func RunKubeStateMetricsWrapper(opts *options.Options) {
 		crcViper.SetConfigFile(opts.CustomResourceConfigFile)
 		if err := crcViper.ReadInConfig(); err != nil {
 			if errors.Is(err, viper.ConfigFileNotFoundError{}) {
-				klog.InfoS(err, "Custom resource configuration file not found", "file", opts.CustomResourceConfigFile)
+				klog.InfoS("Custom resource configuration file not found at startup", "file", opts.CustomResourceConfigFile)
 			} else if _, err = os.Stat(filepath.Clean(opts.CustomResourceConfigFile)); os.IsNotExist(err) {
 				// Adding this check in addition to the above since viper.ConfigFileNotFoundError is not working as expected due to this issue -
 				// https://github.com/spf13/viper/issues/1783

pkg/app/server.go

@@ -181,15 +181,18 @@ func RunKubeStateMetrics(ctx context.Context, opts *options.Options) error {
 	}
 
 	if opts.CustomResourceConfigFile != "" {
-		crcFile, err := os.ReadFile(filepath.Clean(opts.CustomResourceConfigFile))
-		if err != nil {
-			return fmt.Errorf("failed to read custom resource config file: %v", err)
+		if _, err := os.Stat(filepath.Clean(opts.CustomResourceConfigFile)); os.IsNotExist(err) {
+			klog.InfoS("config file does not exist,ignoring", "file", opts.CustomResourceConfigFile)
+		} else {
+			crcFile, err := os.ReadFile(filepath.Clean(opts.CustomResourceConfigFile))
+			if err != nil {
+				return fmt.Errorf("failed to read custom resource config file: %v", err)
+			}
+			configSuccess.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).Set(1)
+			configSuccessTime.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).SetToCurrentTime()
+			hash := md5HashAsMetricValue(crcFile)
+			configHash.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).Set(hash)
 		}
-		configSuccess.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).Set(1)
-		configSuccessTime.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).SetToCurrentTime()
-		hash := md5HashAsMetricValue(crcFile)
-		configHash.WithLabelValues("customresourceconfig", filepath.Clean(opts.CustomResourceConfigFile)).Set(hash)
-
 	}
 
 	resources := []string{}
@@ -543,11 +546,17 @@ func resolveCustomResourceConfig(opts *options.Options) (customresourcestate.Con
 		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("unable to open Custom Resource State Metrics file: %v", err)
+		if opts.ContinueWithoutCustomResourceConfigFile {
+			if _, err := os.Stat(filepath.Clean(file)); os.IsNotExist(err) {
+				klog.InfoS("custom resource config file does not exist,ignoring", "file", file)
+			}
+		} else {
+			f, err := os.Open(filepath.Clean(file))
+			if err != nil {
+				return nil, fmt.Errorf("unable to open Custom Resource State Metrics file: %v", err)
+			}
+			return yaml.NewDecoder(f), nil
 		}
-		return yaml.NewDecoder(f), nil
 	}
 	return nil, nil
 }

pkg/options/options.go

@@ -47,19 +47,21 @@ type Options struct {
 	MetricOptInList      MetricSet       `yaml:"metric_opt_in_list"`
 	Resources            ResourceSet     `yaml:"resources"`
 
-	cmd                      *cobra.Command
-	Apiserver                string   `yaml:"apiserver"`
-	CustomResourceConfig     string   `yaml:"custom_resource_config"`
-	CustomResourceConfigFile string   `yaml:"custom_resource_config_file"`
-	Host                     string   `yaml:"host"`
-	Kubeconfig               string   `yaml:"kubeconfig"`
-	Namespace                string   `yaml:"namespace"`
-	Node                     NodeType `yaml:"node"`
-	Pod                      string   `yaml:"pod"`
-	TLSConfig                string   `yaml:"tls_config"`
-	TelemetryHost            string   `yaml:"telemetry_host"`
-
-	Config string
+	cmd                                     *cobra.Command
+	Apiserver                               string   `yaml:"apiserver"`
+	CustomResourceConfig                    string   `yaml:"custom_resource_config"`
+	CustomResourceConfigFile                string   `yaml:"custom_resource_config_file"`
+	ContinueWithoutCustomResourceConfigFile bool     `yaml:"continue_without_custom_resource_config_file"`
+	Host                                    string   `yaml:"host"`
+	Kubeconfig                              string   `yaml:"kubeconfig"`
+	Namespace                               string   `yaml:"namespace"`
+	Node                                    NodeType `yaml:"node"`
+	Pod                                     string   `yaml:"pod"`
+	TLSConfig                               string   `yaml:"tls_config"`
+	TelemetryHost                           string   `yaml:"telemetry_host"`
+
+	Config                string
+	ContinueWithoutConfig bool `yaml:"continue_without_config"`
 
 	Namespaces              NamespaceList `yaml:"namespaces"`
 	NamespacesDenylist      NamespaceList `yaml:"namespaces_denylist"`