Make it possible to run nfd as a DaemonSet (#105)

* Re-order imports in main.go alphabetically * Refactor argument parsing * Run nfd periodically in a loop by default * Implement --sleep-interval command line option * Add template for running nfd as a Kubernetes DaemonSet
2025-03-28 02:37:11 +00:00 · 2018-04-11 19:33:06 +03:00 · 2018-04-11 19:33:06 +03:00 · 01e2110a5c
commit 01e2110a5c
parent 0150183f60
5 changed files with 187 additions and 78 deletions
--- a/README.md
+++ b/README.md
@ -33,7 +33,8 @@ This project uses GitHub [milestones](https://github.com/kubernetes-incubator/no
 node-feature-discovery.

  Usage:
-  node-feature-discovery [--no-publish --sources=<sources> --label-whitelist=<pattern>]
+  node-feature-discovery [--no-publish] [--sources=<sources>] [--label-whitelist=<pattern>]
+     [--oneshot | --sleep-interval=<seconds>]
  node-feature-discovery -h | --help
  node-feature-discovery --version

@ -46,6 +47,10 @@ node-feature-discovery.
                              cluster-local Kubernetes API server.
  --label-whitelist=<pattern> Regular expression to filter label names to
                              publish to the Kubernetes API server. [Default: ]
+  --oneshot                   Label once and exit.
+  --sleep-interval=<seconds>  Time to sleep between re-labeling. Non-positive
+                              value implies no re-labeling (i.e. infinite
+                              sleep). [Default: 60s]
 ```

 ## Feature discovery
@ -166,8 +171,20 @@ such as restricting discovered features with the --label-whitelist option._

 ### Usage

-Feature discovery is done as a one-shot job. There is an example script in this
-repo that demonstrates how to deploy the job to unlabeled nodes.
+Feature discovery is preferably run as a Kubernetes DaemonSet. There is an
+example spec that can be used as a template, or, as is when just trying out the
+service:
+```
+kubectl create -f node-feature-discovery-daemonset.json.template
+```
+
+When run as a daemonset, nodes are re-labeled at an interval specified using
+the `--sleep-interval` option. In the [template](https://github.com/kubernetes-incubator/node-feature-discovery/blob/master/node-feature-discovery-daemonset.json.template#L38) the default interval is set to 60s
+which is also the default when no `--sleep-interval` is specified.
+
+Feature discovery can alternatively be configured as a one-shot job. There is
+an example script in this repo that demonstrates how to deploy the job to
+unlabeled nodes.

 ```
 ./label-nodes.sh
--- a/main.go
+++ b/main.go
@ -6,6 +6,7 @@ import (
 	"os"
 	"regexp"
 	"strings"
+	"time"

 	"github.com/docopt/docopt-go"
 	"github.com/kubernetes-incubator/node-feature-discovery/source"
@ -15,9 +16,9 @@ import (
 	"github.com/kubernetes-incubator/node-feature-discovery/source/network"
 	"github.com/kubernetes-incubator/node-feature-discovery/source/panic_fake"
 	"github.com/kubernetes-incubator/node-feature-discovery/source/pstate"
-	"github.com/kubernetes-incubator/node-feature-discovery/source/storage"
 	"github.com/kubernetes-incubator/node-feature-discovery/source/rdt"
 	"github.com/kubernetes-incubator/node-feature-discovery/source/selinux"
+	"github.com/kubernetes-incubator/node-feature-discovery/source/storage"
 	api "k8s.io/api/core/v1"
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	k8sclient "k8s.io/client-go/kubernetes"
@ -71,6 +72,15 @@ type APIHelpers interface {
 	UpdateNode(*k8sclient.Clientset, *api.Node) error
 }

+// Command line arguments
+type Args struct {
+	labelWhiteList string
+	noPublish      bool
+	oneshot        bool
+	sleepInterval  time.Duration
+	sources        []string
+}
+
 func main() {
 	// Assert that the version is known
 	if version == "" {
@ -78,32 +88,47 @@ func main() {
 	}

 	// Parse command-line arguments.
-	noPublish, sourcesArg, whiteListArg := argsParse(nil)
+	args := argsParse(nil)

 	// Configure the parameters for feature discovery.
-	sources, labelWhiteList, err := configureParameters(sourcesArg, whiteListArg)
+	enabledSources, labelWhiteList, err := configureParameters(args.sources, args.labelWhiteList)
 	if err != nil {
 		stderrLogger.Fatalf("error occurred while configuring parameters: %s", err.Error())
 	}

-	// Get the set of feature labels.
-	labels := createFeatureLabels(sources, labelWhiteList)
-
 	helper := APIHelpers(k8sHelpers{})
-	// Update the node with the feature labels.
-	err = updateNodeWithFeatureLabels(helper, noPublish, labels)
-	if err != nil {
-		stderrLogger.Fatalf("error occurred while updating node with feature labels: %s", err.Error())
+
+	for {
+		// Get the set of feature labels.
+		labels := createFeatureLabels(enabledSources, labelWhiteList)
+
+		// Update the node with the feature labels.
+		err = updateNodeWithFeatureLabels(helper, args.noPublish, labels)
+		if err != nil {
+			stderrLogger.Fatalf("error occurred while updating node with feature labels: %s", err.Error())
+		}
+
+		if args.oneshot {
+			break
+		}
+
+		if args.sleepInterval > 0 {
+			time.Sleep(args.sleepInterval)
+		} else {
+			// Sleep forever
+			select {}
+		}
 	}
 }

 // argsParse parses the command line arguments passed to the program.
 // The argument argv is passed only for testing purposes.
-func argsParse(argv []string) (noPublish bool, sourcesArg []string, whiteListArg string) {
+func argsParse(argv []string) (args Args) {
 	usage := fmt.Sprintf(`%s.

  Usage:
-  %s [--no-publish --sources=<sources> --label-whitelist=<pattern>]
+  %s [--no-publish] [--sources=<sources>] [--label-whitelist=<pattern>]
+     [--oneshot | --sleep-interval=<seconds>]
  %s -h | --help
  %s --version

@ -115,7 +140,11 @@ func argsParse(argv []string) (noPublish bool, sourcesArg []string, whiteListArg
  --no-publish                Do not publish discovered features to the
                              cluster-local Kubernetes API server.
  --label-whitelist=<pattern> Regular expression to filter label names to
-                              publish to the Kubernetes API server. [Default: ]`,
+                              publish to the Kubernetes API server. [Default: ]
+  --oneshot                   Label once and exit.
+  --sleep-interval=<seconds>  Time to sleep between re-labeling. Non-positive
+                              value implies no re-labeling (i.e. infinite
+                              sleep). [Default: 60s]`,
 		ProgramName,
 		ProgramName,
 		ProgramName,
@ -126,19 +155,32 @@ func argsParse(argv []string) (noPublish bool, sourcesArg []string, whiteListArg
 		fmt.Sprintf("%s %s", ProgramName, version), false)

 	// Parse argument values as usable types.
-	noPublish = arguments["--no-publish"].(bool)
-	sourcesArg = strings.Split(arguments["--sources"].(string), ",")
-	whiteListArg = arguments["--label-whitelist"].(string)
+	var err error
+	args.noPublish = arguments["--no-publish"].(bool)
+	args.sources = strings.Split(arguments["--sources"].(string), ",")
+	args.labelWhiteList = arguments["--label-whitelist"].(string)
+	args.oneshot = arguments["--oneshot"].(bool)
+	args.sleepInterval, err = time.ParseDuration(arguments["--sleep-interval"].(string))

-	return noPublish, sourcesArg, whiteListArg
+	// Check that sleep interval has a sane value
+	if err != nil {
+		stderrLogger.Fatalf("invalid --sleep-interval specified: %s", err.Error())
+	}
+	if args.sleepInterval > 0 && args.sleepInterval < time.Second {
+		stderrLogger.Printf("WARNING: too short sleep-intervall specified (%s), forcing to 1s", args.sleepInterval.String())
+		args.sleepInterval = time.Second
+	}
+
+	return args
 }

 // configureParameters returns all the variables required to perform feature
 // discovery based on command line arguments.
-func configureParameters(sourcesArg []string, whiteListArg string) (sources []source.FeatureSource, labelWhiteList *regexp.Regexp, err error) {
-	enabledSources := map[string]struct{}{}
-	for _, s := range sourcesArg {
-		enabledSources[strings.TrimSpace(s)] = struct{}{}
+func configureParameters(sourcesWhiteList []string, labelWhiteListStr string) (enabledSources []source.FeatureSource, labelWhiteList *regexp.Regexp, err error) {
+	// A map for lookup
+	sourcesWhiteListMap := map[string]struct{}{}
+	for _, s := range sourcesWhiteList {
+		sourcesWhiteListMap[strings.TrimSpace(s)] = struct{}{}
 	}

 	// Configure feature sources.
@ -154,21 +196,21 @@ func configureParameters(sourcesArg []string, whiteListArg string) (sources []so
 		panic_fake.Source{},
 	}

-	sources = []source.FeatureSource{}
+	enabledSources = []source.FeatureSource{}
 	for _, s := range allSources {
-		if _, enabled := enabledSources[s.Name()]; enabled {
-			sources = append(sources, s)
+		if _, enabled := sourcesWhiteListMap[s.Name()]; enabled {
+			enabledSources = append(enabledSources, s)
 		}
 	}

-	// Compile whiteListArg regex
-	labelWhiteList, err = regexp.Compile(whiteListArg)
+	// Compile labelWhiteList regex
+	labelWhiteList, err = regexp.Compile(labelWhiteListStr)
 	if err != nil {
-		stderrLogger.Printf("error parsing whitelist regex (%s): %s", whiteListArg, err)
+		stderrLogger.Printf("error parsing whitelist regex (%s): %s", labelWhiteListStr, err)
 		return nil, nil, err
 	}

-	return sources, labelWhiteList, nil
+	return enabledSources, labelWhiteList, nil
 }

 // createFeatureLabels returns the set of feature labels from the enabled
--- a/main_test.go
+++ b/main_test.go
@ -4,6 +4,7 @@ import (
 	"fmt"
 	"regexp"
 	"testing"
+	"time"

 	"github.com/kubernetes-incubator/node-feature-discovery/source"
 	"github.com/kubernetes-incubator/node-feature-discovery/source/fake"
@ -122,48 +123,52 @@ func TestDiscoveryWithMockSources(t *testing.T) {

 func TestArgsParse(t *testing.T) {
 	Convey("When parsing command line arguments", t, func() {
-		argv1 := []string{"--no-publish"}
-		argv2 := []string{"--sources=fake1,fake2,fake3"}
+		argv1 := []string{"--no-publish", "--oneshot"}
+		argv2 := []string{"--sources=fake1,fake2,fake3", "--sleep-interval=30s"}
 		argv3 := []string{"--label-whitelist=.*rdt.*"}
 		argv4 := []string{"--no-publish", "--sources=fake1,fake2,fake3"}

-		Convey("When --no-publish flag is passed", func() {
-			noPublish, sourcesArg, whiteListArg := argsParse(argv1)
+		Convey("When --no-publish and --oneshot flags are passed", func() {
+			args := argsParse(argv1)

-			Convey("noPublish is set and sourcesArg is set to the default value", func() {
-				So(noPublish, ShouldBeTrue)
-				So(sourcesArg, ShouldResemble, []string{"cpuid", "rdt", "pstate", "memory", "network", "storage", "selinux"})
-				So(len(whiteListArg), ShouldEqual, 0)
+			Convey("noPublish is set and args.sources is set to the default value", func() {
+				So(args.sleepInterval, ShouldEqual, 60*time.Second)
+				So(args.noPublish, ShouldBeTrue)
+				So(args.oneshot, ShouldBeTrue)
+				So(args.sources, ShouldResemble, []string{"cpuid", "rdt", "pstate", "memory", "network", "storage", "selinux"})
+				So(len(args.labelWhiteList), ShouldEqual, 0)
 			})
 		})

-		Convey("When --sources flag is passed and set to some values", func() {
-			noPublish, sourcesArg, whiteListArg := argsParse(argv2)
+		Convey("When --sources flag is passed and set to some values, --sleep-inteval is specified", func() {
+			args := argsParse(argv2)

-			Convey("sourcesArg is set to appropriate values", func() {
-				So(noPublish, ShouldBeFalse)
-				So(sourcesArg, ShouldResemble, []string{"fake1", "fake2", "fake3"})
-				So(len(whiteListArg), ShouldEqual, 0)
+			Convey("args.sources is set to appropriate values", func() {
+				So(args.sleepInterval, ShouldEqual, 30*time.Second)
+				So(args.noPublish, ShouldBeFalse)
+				So(args.oneshot, ShouldBeFalse)
+				So(args.sources, ShouldResemble, []string{"fake1", "fake2", "fake3"})
+				So(len(args.labelWhiteList), ShouldEqual, 0)
 			})
 		})

 		Convey("When --label-whitelist flag is passed and set to some value", func() {
-			noPublish, sourcesArg, whiteListArg := argsParse(argv3)
+			args := argsParse(argv3)

-			Convey("whiteListArg is set to appropriate value and sourcesArg is set to default value", func() {
-				So(noPublish, ShouldBeFalse)
-				So(sourcesArg, ShouldResemble, []string{"cpuid", "rdt", "pstate", "memory", "network", "storage","selinux"})
-				So(whiteListArg, ShouldResemble, ".*rdt.*")
+			Convey("args.labelWhiteList is set to appropriate value and args.sources is set to default value", func() {
+				So(args.noPublish, ShouldBeFalse)
+				So(args.sources, ShouldResemble, []string{"cpuid", "rdt", "pstate", "memory", "network", "storage", "selinux"})
+				So(args.labelWhiteList, ShouldResemble, ".*rdt.*")
 			})
 		})

 		Convey("When --no-publish and --sources flag are passed and --sources flag is set to some value", func() {
-			noPublish, sourcesArg, whiteListArg := argsParse(argv4)
+			args := argsParse(argv4)

-			Convey("--no-publish is set and sourcesArg is set to appropriate values", func() {
-				So(noPublish, ShouldBeTrue)
-				So(sourcesArg, ShouldResemble, []string{"fake1", "fake2", "fake3"})
-				So(len(whiteListArg), ShouldEqual, 0)
+			Convey("--no-publish is set and args.sources is set to appropriate values", func() {
+				So(args.noPublish, ShouldBeTrue)
+				So(args.sources, ShouldResemble, []string{"fake1", "fake2", "fake3"})
+				So(len(args.labelWhiteList), ShouldEqual, 0)
 			})
 		})
 	})
@ -172,60 +177,60 @@ func TestArgsParse(t *testing.T) {
 func TestConfigureParameters(t *testing.T) {
 	Convey("When configuring parameters for node feature discovery", t, func() {

-		Convey("When no sourcesArg and whiteListArg are passed", func() {
-			sourcesArg := []string{}
-			whiteListArg := ""
+		Convey("When no sourcesWhiteList and labelWhiteListStr are passed", func() {
+			sourcesWhiteList := []string{}
+			labelWhiteListStr := ""
 			emptyRegexp, _ := regexp.Compile("")
-			sources, labelWhiteList, err := configureParameters(sourcesArg, whiteListArg)
+			enabledSources, labelWhiteList, err := configureParameters(sourcesWhiteList, labelWhiteListStr)

 			Convey("Error should not be produced", func() {
 				So(err, ShouldBeNil)
 			})
-			Convey("No sources or labelWhiteList are returned", func() {
-				So(len(sources), ShouldEqual, 0)
+			Convey("No sourcesWhiteList or labelWhiteList are returned", func() {
+				So(len(enabledSources), ShouldEqual, 0)
 				So(labelWhiteList, ShouldResemble, emptyRegexp)
 			})
 		})

-		Convey("When sourcesArg is passed", func() {
-			sourcesArg := []string{"fake"}
-			whiteListArg := ""
+		Convey("When sourcesWhiteList is passed", func() {
+			sourcesWhiteList := []string{"fake"}
+			labelWhiteListStr := ""
 			emptyRegexp, _ := regexp.Compile("")
-			sources, labelWhiteList, err := configureParameters(sourcesArg, whiteListArg)
+			enabledSources, labelWhiteList, err := configureParameters(sourcesWhiteList, labelWhiteListStr)

 			Convey("Error should not be produced", func() {
 				So(err, ShouldBeNil)
 			})
-			Convey("Proper sources are returned", func() {
-				So(len(sources), ShouldEqual, 1)
-				So(sources[0], ShouldHaveSameTypeAs, fake.Source{})
+			Convey("Proper sourcesWhiteList are returned", func() {
+				So(len(enabledSources), ShouldEqual, 1)
+				So(enabledSources[0], ShouldHaveSameTypeAs, fake.Source{})
 				So(labelWhiteList, ShouldResemble, emptyRegexp)
 			})
 		})

-		Convey("When invalid whiteListArg is passed", func() {
-			sourcesArg := []string{""}
-			whiteListArg := "*"
-			sources, labelWhiteList, err := configureParameters(sourcesArg, whiteListArg)
+		Convey("When invalid labelWhiteListStr is passed", func() {
+			sourcesWhiteList := []string{""}
+			labelWhiteListStr := "*"
+			enabledSources, labelWhiteList, err := configureParameters(sourcesWhiteList, labelWhiteListStr)

 			Convey("Error is produced", func() {
-				So(sources, ShouldBeNil)
+				So(enabledSources, ShouldBeNil)
 				So(labelWhiteList, ShouldBeNil)
 				So(err, ShouldNotBeNil)
 			})
 		})

-		Convey("When valid whiteListArg is passed", func() {
-			sourcesArg := []string{""}
-			whiteListArg := ".*rdt.*"
+		Convey("When valid labelWhiteListStr is passed", func() {
+			sourcesWhiteList := []string{""}
+			labelWhiteListStr := ".*rdt.*"
 			expectRegexp, err := regexp.Compile(".*rdt.*")
-			sources, labelWhiteList, err := configureParameters(sourcesArg, whiteListArg)
+			enabledSources, labelWhiteList, err := configureParameters(sourcesWhiteList, labelWhiteListStr)

 			Convey("Error should not be produced", func() {
 				So(err, ShouldBeNil)
 			})
 			Convey("Proper labelWhiteList is returned", func() {
-				So(len(sources), ShouldEqual, 0)
+				So(len(enabledSources), ShouldEqual, 0)
 				So(labelWhiteList, ShouldResemble, expectRegexp)
 			})
 		})
--- a/node-feature-discovery-daemonset.json.template
+++ b/node-feature-discovery-daemonset.json.template
@ -0,0 +1,44 @@
+{
+  "apiVersion": "apps/v1",
+  "kind": "DaemonSet",
+  "metadata": {
+    "labels": {
+      "app": "node-feature-discovery"
+    },
+    "name": "node-feature-discovery"
+  },
+  "spec": {
+    "selector": {
+      "matchLabels": {
+        "app": "node-feature-discovery"
+      }
+    },
+    "template": {
+      "metadata": {
+        "labels": {
+          "app": "node-feature-discovery"
+        }
+      },
+      "spec": {
+        "hostNetwork": true,
+        "containers": [
+          {
+            "env": [
+              {
+                "name": "NODE_NAME",
+                "valueFrom": {
+                  "fieldRef": {
+                    "fieldPath": "spec.nodeName"
+                  }
+                }
+              }
+            ],
+            "image": "quay.io/kubernetes_incubator/node-feature-discovery:v0.1.0",
+            "name": "node-feature-discovery",
+            "args": ["--sleep-interval=60s"]
+          }
+        ]
+      }
+    }
+  }
+}
--- a/node-feature-discovery-job.json.template
+++ b/node-feature-discovery-job.json.template
@ -32,6 +32,7 @@
            ],
            "image": "quay.io/kubernetes_incubator/node-feature-discovery:v0.1.0",
            "name": "node-feature-discovery",
+            "args": ["--oneshot"],
            "ports": [
              {
                "containerPort": 7156,