feat: add ability to export features for static node

cmd/nfd/subcmd/export/export.go

@@ -0,0 +1,36 @@
+/*
+Copyright 2025 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 export
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var ExportCmd = &cobra.Command{
+	Use:   "export",
+	Short: "Export commands",
+}
+
+func Execute() {
+	if err := ExportCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}

cmd/nfd/subcmd/export/features.go

@@ -0,0 +1,68 @@
+/*
+Copyright 2025 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 export
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"sigs.k8s.io/node-feature-discovery/source"
+)
+
+func NewExportCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "features",
+		Short: "Export features for given node",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			sources := map[string]source.FeatureSource{}
+			for k, v := range source.GetAllFeatureSources() {
+				if ts, ok := v.(source.SupplementalSource); ok && ts.DisableByDefault() {
+					continue
+				}
+				sources[k] = v
+			}
+
+			// Discover all feature sources
+			for _, s := range sources {
+				if err := s.Discover(); err != nil {
+					return fmt.Errorf("error during discovery of source %s: %w", s.Name(), err)
+				}
+			}
+
+			features := source.GetAllFeatures()
+			exportedLabels, err := json.MarshalIndent(features, "", "    ")
+			if err != nil {
+				return err
+			}
+
+			if outputPath != "" {
+				err = writeToFile(outputPath, string(exportedLabels))
+			} else {
+				fmt.Println(string(exportedLabels))
+			}
+			return err
+		},
+	}
+	cmd.Flags().StringVar(&outputPath, "path", "", "export to this JSON path")
+	return cmd
+}
+
+func init() {
+	ExportCmd.AddCommand(NewExportCmd())
+}

cmd/nfd/subcmd/export/labels.go

@@ -0,0 +1,102 @@
+/*
+Copyright 2025 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 export
+
+import (
+	"encoding/json"
+	"fmt"
+	"maps"
+	"regexp"
+	"slices"
+	"sort"
+
+	"github.com/spf13/cobra"
+	"k8s.io/klog/v2"
+
+	worker "sigs.k8s.io/node-feature-discovery/pkg/nfd-worker"
+	"sigs.k8s.io/node-feature-discovery/source"
+)
+
+func NewLabelsCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "labels",
+		Short: "Export feature labels for given node",
+		RunE: func(cmd *cobra.Command, args []string) error {
+
+			// Determine enabled feature sources
+			featureSources := make(map[string]source.FeatureSource)
+			for n, s := range source.GetAllFeatureSources() {
+				if ts, ok := s.(source.SupplementalSource); !ok || !ts.DisableByDefault() {
+					err := s.Discover()
+					if err != nil {
+						return err
+					}
+					featureSources[n] = s
+				}
+			}
+			featureSourceList := slices.Collect(maps.Values(featureSources))
+			sort.Slice(featureSourceList, func(i, j int) bool { return featureSourceList[i].Name() < featureSourceList[j].Name() })
+
+			// Determine enabled label sources
+			labelSources := make(map[string]source.LabelSource)
+			for n, s := range source.GetAllLabelSources() {
+				if ts, ok := s.(source.SupplementalSource); !ok || !ts.DisableByDefault() {
+					labelSources[n] = s
+				}
+			}
+			labelSourcesList := slices.Collect(maps.Values(labelSources))
+			sort.Slice(labelSourcesList, func(i, j int) bool {
+				iP, jP := labelSourcesList[i].Priority(), labelSourcesList[j].Priority()
+				if iP != jP {
+					return iP < jP
+				}
+				return labelSourcesList[i].Name() < labelSourcesList[j].Name()
+			})
+
+			labels := worker.Labels{}
+			labelWhiteList := *regexp.MustCompile("")
+
+			// Get labels from all enabled label sources
+			for _, source := range labelSourcesList {
+				labelsFromSource, err := worker.GetFeatureLabels(source, labelWhiteList)
+				if err != nil {
+					klog.ErrorS(err, "discovery failed", "source", source.Name())
+					continue
+				}
+				maps.Copy(labels, labelsFromSource)
+			}
+
+			exportedLabels, err := json.MarshalIndent(labels, "", "    ")
+			if err != nil {
+				return err
+			}
+
+			if outputPath != "" {
+				err = writeToFile(outputPath, string(exportedLabels))
+			} else {
+				fmt.Println(string(exportedLabels))
+			}
+			return err
+		},
+	}
+	cmd.Flags().StringVar(&outputPath, "path", "", "export to this JSON path")
+	return cmd
+}
+
+func init() {
+	ExportCmd.AddCommand(NewLabelsCmd())
+}

cmd/nfd/subcmd/export/utils.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2025 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 export
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	outputPath string
+)
+
+// writeToFile saves string content to a file at the path set by path
+func writeToFile(path, content string) error {
+	fd, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	defer fd.Close()
+	_, err = fmt.Fprint(fd, content)
+	return err
+}

cmd/nfd/subcmd/root.go

@@ -23,6 +23,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"sigs.k8s.io/node-feature-discovery/cmd/nfd/subcmd/compat"
+	"sigs.k8s.io/node-feature-discovery/cmd/nfd/subcmd/export"
 )
 
 // RootCmd represents the base command when called without any subcommands
@@ -33,6 +34,7 @@ var RootCmd = &cobra.Command{
 
 func init() {
 	RootCmd.AddCommand(compat.CompatCmd)
+	RootCmd.AddCommand(export.ExportCmd)
 }
 
 // Execute adds all child commands to the root command and sets flags appropriately.

docs/usage/nfd-export.md

@@ -0,0 +1,58 @@
+---
+title: "Export"
+layout: default
+sort: 12
+---
+
+# Feature Export
+{: .no_toc}
+
+## Table of contents
+{: .no_toc .text-delta}
+
+1. TOC
+{:toc}
+
+---
+
+## Export
+
+If you are interested in exporting features or labels in a generic
+context, the nfd client supports an export mode, where both can be
+derived on the command line.
+
+### Features
+
+**Feature export is in the experimental version.**
+
+This addresses use cases such as high performance computing (HPC) and
+other environments with compute nodes that warrant assessment, but may
+not have Kubernetes running, or may not be able to or want to run a
+central daemon service for data. To export features, you can use `nfd
+export features`:
+
+```bash
+nfd export features
+```
+
+By default, JSON structure with parsed key value pairs will appear in the
+terminal. To save to a file path:
+
+```bash
+nfd export features --path features.json
+```
+
+### Labels
+
+To export equivalent labels outside of a Kubernetes context,
+you can use `nfd export labels`.
+
+```bash
+nfd export labels
+```
+
+Or export to an output file:
+
+```bash
+nfd export labels --path labels.json
+```

pkg/nfd-worker/nfd-worker-internal_test.go

@@ -54,7 +54,7 @@ func TestGetLabelsWithMockSources(t *testing.T) {
 			mockLabelSource.On("Name").Return(fakeLabelSourceName)
 			mockLabelSource.On("GetLabels").Return(fakeFeatures, nil)
 
-			returnedLabels, err := getFeatureLabels(fakeLabelSource, labelWhiteList.Regexp)
+			returnedLabels, err := GetFeatureLabels(fakeLabelSource, labelWhiteList.Regexp)
 			Convey("Proper label is returned", func() {
 				So(returnedLabels, ShouldResemble, fakeFeatureLabels)
 			})
@@ -67,7 +67,7 @@ func TestGetLabelsWithMockSources(t *testing.T) {
 			expectedError := errors.New("fake error")
 			mockLabelSource.On("GetLabels").Return(nil, expectedError)
 
-			returnedLabels, err := getFeatureLabels(fakeLabelSource, labelWhiteList.Regexp)
+			returnedLabels, err := GetFeatureLabels(fakeLabelSource, labelWhiteList.Regexp)
 			Convey("No label is returned", func() {
 				So(returnedLabels, ShouldBeNil)
 			})

pkg/nfd-worker/nfd-worker.go

@@ -537,7 +537,7 @@ func createFeatureLabels(sources []source.LabelSource, labelWhiteList regexp.Reg
 	// Get labels from all enabled label sources
 	klog.InfoS("starting feature discovery...")
 	for _, source := range sources {
-		labelsFromSource, err := getFeatureLabels(source, labelWhiteList)
+		labelsFromSource, err := GetFeatureLabels(source, labelWhiteList)
 		if err != nil {
 			klog.ErrorS(err, "discovery failed", "source", source.Name())
 			continue
@@ -555,7 +555,7 @@ func createFeatureLabels(sources []source.LabelSource, labelWhiteList regexp.Reg
 
 // getFeatureLabels returns node labels for features discovered by the
 // supplied source.
-func getFeatureLabels(source source.LabelSource, labelWhiteList regexp.Regexp) (labels Labels, err error) {
+func GetFeatureLabels(source source.LabelSource, labelWhiteList regexp.Regexp) (labels Labels, err error) {
 	labels = Labels{}
 	features, err := source.GetLabels()
 	if err != nil {