Revert "Revert "[WIP] southbound networking hooks in kubelet""

cmd/kubelet/app/plugins.go

@@ -20,6 +20,9 @@ package app
 import (
 	// Credential providers
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/credentialprovider/gcp"
+	// Network plugins
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/network"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/network/exec"
 	// Volume plugins
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/volume"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/volume/empty_dir"
@@ -44,3 +47,13 @@ func ProbeVolumePlugins() []volume.Plugin {
 
 	return allPlugins
 }
+
+// ProbeNetworkPlugins collects all compiled-in plugins
+func ProbeNetworkPlugins() []network.NetworkPlugin {
+	allPlugins := []network.NetworkPlugin{}
+
+	// for each existing plugin, add to the list
+	allPlugins = append(allPlugins, exec.ProbeNetworkPlugins()...)
+
+	return allPlugins
+}

cmd/kubelet/app/server.go

@@ -33,6 +33,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/cadvisor"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/config"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/dockertools"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/network"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/volume"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/master/ports"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
@@ -79,6 +80,7 @@ type KubeletServer struct {
 	StreamingConnectionIdleTimeout time.Duration
 	ImageGCHighThresholdPercent    int
 	ImageGCLowThresholdPercent     int
+	NetworkPluginName              string
 }
 
 // NewKubeletServer will create a new KubeletServer with default values.
@@ -104,6 +106,7 @@ func NewKubeletServer() *KubeletServer {
 		MasterServiceNamespace:      api.NamespaceDefault,
 		ImageGCHighThresholdPercent: 90,
 		ImageGCLowThresholdPercent:  80,
+		NetworkPluginName:           "",
 	}
 }
 
@@ -142,6 +145,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.DurationVar(&s.StreamingConnectionIdleTimeout, "streaming_connection_idle_timeout", 0, "Maximum time a streaming connection can be idle before the connection is automatically closed.  Example: '5m'")
 	fs.IntVar(&s.ImageGCHighThresholdPercent, "image_gc_high_threshold", s.ImageGCHighThresholdPercent, "The percent of disk usage after which image garbage collection is always run. Default: 90%%")
 	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.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")
 }
 
 // Run runs the specified KubeletServer.  This should never exit.
@@ -200,6 +204,8 @@ func (s *KubeletServer) Run(_ []string) error {
 		KubeClient:                     client,
 		MasterServiceNamespace:         s.MasterServiceNamespace,
 		VolumePlugins:                  ProbeVolumePlugins(),
+		NetworkPlugins:                 ProbeNetworkPlugins(),
+		NetworkPluginName:              s.NetworkPluginName,
 		StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout,
 		ImageGCPolicy:                  imageGCPolicy,
 	}
@@ -397,6 +403,8 @@ type KubeletConfig struct {
 	Runonce                        bool
 	MasterServiceNamespace         string
 	VolumePlugins                  []volume.Plugin
+	NetworkPlugins                 []network.NetworkPlugin
+	NetworkPluginName              string
 	StreamingConnectionIdleTimeout time.Duration
 	Recorder                       record.EventRecorder
 	TLSOptions                     *kubelet.TLSOptions
@@ -437,6 +445,8 @@ func createAndInitKubelet(kc *KubeletConfig, pc *config.PodConfig) (*kubelet.Kub
 		net.IP(kc.ClusterDNS),
 		kc.MasterServiceNamespace,
 		kc.VolumePlugins,
+		kc.NetworkPlugins,
+		kc.NetworkPluginName,
 		kc.StreamingConnectionIdleTimeout,
 		kc.Recorder,
 		kc.CadvisorInterface,