Allow specification of network plugins directory when starting kubelet

cmd/kubelet/app/plugins.go

@@ -69,11 +69,11 @@ func ProbeVolumePlugins() []volume.VolumePlugin {
 }
 
 // ProbeNetworkPlugins collects all compiled-in plugins
-func ProbeNetworkPlugins() []network.NetworkPlugin {
+func ProbeNetworkPlugins(pluginDir string) []network.NetworkPlugin {
 	allPlugins := []network.NetworkPlugin{}
 
 	// for each existing plugin, add to the list
-	allPlugins = append(allPlugins, exec.ProbeNetworkPlugins()...)
+	allPlugins = append(allPlugins, exec.ProbeNetworkPlugins(pluginDir)...)
 
 	return allPlugins
 }

cmd/kubelet/app/server.go

@@ -103,6 +103,7 @@ type KubeletServer struct {
 	ImageGCLowThresholdPercent     int
 	LowDiskSpaceThresholdMB        int
 	NetworkPluginName              string
+	NetworkPluginDir               string
 	CloudProvider                  string
 	CloudConfigFile                string
 	TLSCertFile                    string
@@ -171,6 +172,7 @@ func NewKubeletServer() *KubeletServer {
 		ImageGCLowThresholdPercent:  80,
 		LowDiskSpaceThresholdMB:     256,
 		NetworkPluginName:           "",
+		NetworkPluginDir:            "/usr/libexec/kubernetes/kubelet-plugins/net/exec/",
 		HostNetworkSources:          kubelet.FileSource,
 		CertDirectory:               "/var/run/kubernetes",
 		NodeStatusUpdateFrequency:   10 * time.Second,
@@ -233,6 +235,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.IntVar(&s.ImageGCLowThresholdPercent, "image-gc-low-threshold", s.ImageGCLowThresholdPercent, "The percent of disk usage before which image garbage collection is never run. Lowest disk usage to garbage collect to. Default: 80%%")
 	fs.IntVar(&s.LowDiskSpaceThresholdMB, "low-diskspace-threshold-mb", s.LowDiskSpaceThresholdMB, "The absolute free disk space, in MB, to maintain. When disk space falls below this threshold, new pods would be rejected. Default: 256")
 	fs.StringVar(&s.NetworkPluginName, "network-plugin", s.NetworkPluginName, "<Warning: Alpha feature> The name of the network plugin to be invoked for various events in kubelet/pod lifecycle")
+	fs.StringVar(&s.NetworkPluginDir, "network-plugin-dir", s.NetworkPluginDir, "<Warning: Alpha feature> The full path of the directory in which to search for network plugins")
 	fs.StringVar(&s.CloudProvider, "cloud-provider", s.CloudProvider, "The provider for cloud services.  Empty string for no provider.")
 	fs.StringVar(&s.CloudConfigFile, "cloud-config", s.CloudConfigFile, "The path to the cloud provider configuration file.  Empty string for no configuration file.")
 	fs.StringVar(&s.ResourceContainer, "resource-container", s.ResourceContainer, "Absolute name of the resource-only container to create and run the Kubelet in (Default: /kubelet).")
@@ -347,7 +350,7 @@ func (s *KubeletServer) Run(_ []string) error {
 		KubeClient:                     apiclient,
 		MasterServiceNamespace:         s.MasterServiceNamespace,
 		VolumePlugins:                  ProbeVolumePlugins(),
-		NetworkPlugins:                 ProbeNetworkPlugins(),
+		NetworkPlugins:                 ProbeNetworkPlugins(s.NetworkPluginDir),
 		NetworkPluginName:              s.NetworkPluginName,
 		StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout,
 		TLSOptions:                     tlsOptions,

pkg/kubelet/network/exec/exec.go

@@ -70,14 +70,9 @@ const (
 	initCmd     = "init"
 	setUpCmd    = "setup"
 	tearDownCmd = "teardown"
-	execDir     = "/usr/libexec/kubernetes/kubelet-plugins/net/exec/"
 )
 
-func ProbeNetworkPlugins() []network.NetworkPlugin {
-	return probeNetworkPluginsWithExecDir(execDir)
-}
-
-func probeNetworkPluginsWithExecDir(pluginDir string) []network.NetworkPlugin {
+func ProbeNetworkPlugins(pluginDir string) []network.NetworkPlugin {
 	execPlugins := []network.NetworkPlugin{}
 
 	files, _ := ioutil.ReadDir(pluginDir)

pkg/kubelet/network/exec/exec_test.go

@@ -72,7 +72,7 @@ func TestSelectPlugin(t *testing.T) {
 	defer tearDownPlugin(pluginName)
 	installPluginUnderTest(t, "", pluginName)
 
-	plug, err := network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), pluginName, network.NewFakeHost(nil))
+	plug, err := network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), pluginName, network.NewFakeHost(nil))
 	if err != nil {
 		t.Errorf("Failed to select the desired plugin: %v", err)
 	}
@@ -89,7 +89,7 @@ func TestSelectVendoredPlugin(t *testing.T) {
 	installPluginUnderTest(t, vendor, pluginName)
 
 	vendoredPluginName := fmt.Sprintf("%s/%s", vendor, pluginName)
-	plug, err := network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), vendoredPluginName, network.NewFakeHost(nil))
+	plug, err := network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), vendoredPluginName, network.NewFakeHost(nil))
 	if err != nil {
 		t.Errorf("Failed to select the desired plugin: %v", err)
 	}
@@ -105,7 +105,7 @@ func TestSelectWrongPlugin(t *testing.T) {
 	installPluginUnderTest(t, "", pluginName)
 
 	wrongPlugin := "abcd"
-	plug, err := network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), wrongPlugin, network.NewFakeHost(nil))
+	plug, err := network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), wrongPlugin, network.NewFakeHost(nil))
 	if plug != nil || err == nil {
 		t.Errorf("Expected to see an error. Wrong plugin selected.")
 	}
@@ -127,7 +127,7 @@ func TestPluginValidation(t *testing.T) {
 	}
 	f.Close()
 
-	_, err = network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), pluginName, network.NewFakeHost(nil))
+	_, err = network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), pluginName, network.NewFakeHost(nil))
 	if err == nil {
 		// we expected an error here because validation would have failed
 		t.Errorf("Expected non-nil value.")
@@ -139,7 +139,7 @@ func TestPluginSetupHook(t *testing.T) {
 	defer tearDownPlugin(pluginName)
 	installPluginUnderTest(t, "", pluginName)
 
-	plug, err := network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), pluginName, network.NewFakeHost(nil))
+	plug, err := network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), pluginName, network.NewFakeHost(nil))
 
 	err = plug.SetUpPod("podNamespace", "podName", "dockerid2345")
 	if err != nil {
@@ -161,7 +161,7 @@ func TestPluginTearDownHook(t *testing.T) {
 	defer tearDownPlugin(pluginName)
 	installPluginUnderTest(t, "", pluginName)
 
-	plug, err := network.InitNetworkPlugin(probeNetworkPluginsWithExecDir(testPluginPath), pluginName, network.NewFakeHost(nil))
+	plug, err := network.InitNetworkPlugin(ProbeNetworkPlugins(testPluginPath), pluginName, network.NewFakeHost(nil))
 
 	err = plug.TearDownPod("podNamespace", "podName", "dockerid2345")
 	if err != nil {