Exporting the AddFeatureGate function and adding a unit test for it. (#3661)

pkg/daemons/agent/agent.go

@@ -57,13 +57,6 @@ func startKubelet(cfg *daemonconfig.Agent) error {
 	return executor.Kubelet(args)
 }
 
-func addFeatureGate(current, new string) string {
-	if current == "" {
-		return new
-	}
-	return current + "," + new
-}
-
 // ImageCredProvAvailable checks to see if the kubelet image credential provider bin dir and config
 // files exist and are of the correct types. This is exported so that it may be used by downstream projects.
 func ImageCredProvAvailable(cfg *daemonconfig.Agent) bool {

pkg/daemons/agent/agent_linux.go

@@ -134,7 +134,7 @@ func kubeletArgs(cfg *config.Agent) map[string]string {
 		logrus.Warn("Disabling pod PIDs limit feature due to missing cgroup pids support")
 		argsMap["cgroups-per-qos"] = "false"
 		argsMap["enforce-node-allocatable"] = ""
-		argsMap["feature-gates"] = addFeatureGate(argsMap["feature-gates"], "SupportPodPidsLimit=false")
+		argsMap["feature-gates"] = util.AddFeatureGate(argsMap["feature-gates"], "SupportPodPidsLimit=false")
 	}
 	if kubeletRoot != "" {
 		argsMap["kubelet-cgroups"] = kubeletRoot
@@ -143,7 +143,7 @@ func kubeletArgs(cfg *config.Agent) map[string]string {
 		argsMap["runtime-cgroups"] = runtimeRoot
 	}
 	if system.RunningInUserNS() {
-		argsMap["feature-gates"] = addFeatureGate(argsMap["feature-gates"], "DevicePlugins=false")
+		argsMap["feature-gates"] = util.AddFeatureGate(argsMap["feature-gates"], "DevicePlugins=false")
 	}
 
 	argsMap["node-labels"] = strings.Join(cfg.NodeLabels, ",")
@@ -156,7 +156,7 @@ func kubeletArgs(cfg *config.Agent) map[string]string {
 
 	if ImageCredProvAvailable(cfg) {
 		logrus.Infof("Kubelet image credential provider bin dir and configuration file found.")
-		argsMap["feature-gates"] = addFeatureGate(argsMap["feature-gates"], "KubeletCredentialProviders=true")
+		argsMap["feature-gates"] = util.AddFeatureGate(argsMap["feature-gates"], "KubeletCredentialProviders=true")
 		argsMap["image-credential-provider-bin-dir"] = cfg.ImageCredProvBinDir
 		argsMap["image-credential-provider-config"] = cfg.ImageCredProvConfig
 	}

pkg/daemons/agent/agent_windows.go

@@ -120,7 +120,7 @@ func kubeletArgs(cfg *config.Agent) map[string]string {
 
 	if ImageCredProvAvailable(cfg) {
 		logrus.Infof("Kubelet image credential provider bin dir and configuration file found.")
-		argsMap["feature-gates"] = addFeatureGate(argsMap["feature-gates"], "KubeletCredentialProviders=true")
+		argsMap["feature-gates"] = util.AddFeatureGate(argsMap["feature-gates"], "KubeletCredentialProviders=true")
 		argsMap["image-credential-provider-bin-dir"] = cfg.ImageCredProvBinDir
 		argsMap["image-credential-provider-config"] = cfg.ImageCredProvConfig
 	}

pkg/util/gates.go

+package util
+
+// AddFeatureGate correctly appends a feature gate key pair to the feature gates CLI switch.
+func AddFeatureGate(current, new string) string {
+	if current == "" {
+		return new
+	}
+	return current + "," + new
+}

pkg/util/gates_test.go

+package util
+
+import (
+	"testing"
+)
+
+func TestAddFeatureGate(t *testing.T) {
+	type args struct {
+		currentArg  string
+		featureGate string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "Feature gate added to empty arg",
+			args: args{
+				currentArg:  "",
+				featureGate: "SupportPodPidsLimit=false",
+			},
+			want: "SupportPodPidsLimit=false",
+		},
+		{
+			name: "Feature gate added to existing arg",
+			args: args{
+				currentArg:  "SupportPodPidsLimit=false",
+				featureGate: "DevicePlugins=false",
+			},
+			want: "SupportPodPidsLimit=false,DevicePlugins=false",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := AddFeatureGate(tt.args.currentArg, tt.args.featureGate)
+			if got != tt.want {
+				t.Errorf("error, should be " + tt.want + ", but got " + got)
+			}
+		})
+	}
+}