Remove ExperimentalDockershim from kubelet

Remove one of two uses of Dockershim in `cmd/kubelet`. The other is for
creating a docker client which we pass to the Kubelet... we will handle
that refactor in a separate diff.

I'm fairly confident, though need to double check, that no one is
actually using this experimental dockershim behavior. If they are, I
think we will want to find a new way to support it (that doesn't require
using the Kubelet only to launch Dockershim).

cmd/kubelet/app/BUILD

@@ -61,13 +61,11 @@ go_library(
         "//pkg/kubelet/config:go_default_library",
         "//pkg/kubelet/container:go_default_library",
         "//pkg/kubelet/dockershim:go_default_library",
-        "//pkg/kubelet/dockershim/remote:go_default_library",
         "//pkg/kubelet/eviction:go_default_library",
         "//pkg/kubelet/eviction/api:go_default_library",
         "//pkg/kubelet/kubeletconfig:go_default_library",
         "//pkg/kubelet/kubeletconfig/configfiles:go_default_library",
         "//pkg/kubelet/server:go_default_library",
-        "//pkg/kubelet/server/streaming:go_default_library",
         "//pkg/kubelet/stats/pidlimit:go_default_library",
         "//pkg/kubelet/types:go_default_library",
         "//pkg/util/filesystem:go_default_library",

cmd/kubelet/app/options/container_runtime.go

@@ -51,7 +51,6 @@ func NewContainerRuntimeOptions() *config.ContainerRuntimeOptions {
 		DockershimRootDirectory:    "/var/lib/dockershim",
 		PodSandboxImage:            defaultPodSandboxImage,
 		ImagePullProgressDeadline:  metav1.Duration{Duration: 1 * time.Minute},
-		ExperimentalDockershim:     false,
 
 		//Alpha feature
 		CNIBinDir:   "/opt/cni/bin",

cmd/kubelet/app/server.go

@@ -24,7 +24,6 @@ import (
 	"fmt"
 	"net"
 	"net/http"
-	"net/url"
 	"os"
 	"path"
 	"path/filepath"
@@ -85,13 +84,11 @@ import (
 	"k8s.io/kubernetes/pkg/kubelet/config"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/dockershim"
-	dockerremote "k8s.io/kubernetes/pkg/kubelet/dockershim/remote"
 	"k8s.io/kubernetes/pkg/kubelet/eviction"
 	evictionapi "k8s.io/kubernetes/pkg/kubelet/eviction/api"
 	dynamickubeletconfig "k8s.io/kubernetes/pkg/kubelet/kubeletconfig"
 	"k8s.io/kubernetes/pkg/kubelet/kubeletconfig/configfiles"
 	"k8s.io/kubernetes/pkg/kubelet/server"
-	"k8s.io/kubernetes/pkg/kubelet/server/streaming"
 	"k8s.io/kubernetes/pkg/kubelet/stats/pidlimit"
 	kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
 	utilfs "k8s.io/kubernetes/pkg/util/filesystem"
@@ -259,14 +256,6 @@ HTTP server: The kubelet can also listen for HTTP and respond to a simple API
 			// set up stopCh here in order to be reused by kubelet and docker shim
 			stopCh := genericapiserver.SetupSignalHandler()
 
-			// start the experimental docker shim, if enabled
-			if kubeletServer.KubeletFlags.ExperimentalDockershim {
-				if err := RunDockershim(&kubeletServer.KubeletFlags, kubeletConfig, stopCh); err != nil {
-					klog.Fatal(err)
-				}
-				return
-			}
-
 			// run the kubelet
 			klog.V(5).Infof("KubeletConfiguration: %#v", kubeletServer.KubeletConfiguration)
 			if err := Run(kubeletServer, kubeletDeps, utilfeature.DefaultFeatureGate, stopCh); err != nil {
@@ -1271,51 +1260,3 @@ func BootstrapKubeletConfigController(dynamicConfigDir string, transform dynamic
 	}
 	return kc, c, nil
 }
-
-// RunDockershim only starts the dockershim in current process. This is only used for cri validate testing purpose
-// TODO(random-liu): Move this to a separate binary.
-func RunDockershim(f *options.KubeletFlags, c *kubeletconfiginternal.KubeletConfiguration, stopCh <-chan struct{}) error {
-	r := &f.ContainerRuntimeOptions
-
-	// Initialize docker client configuration.
-	dockerClientConfig := &dockershim.ClientConfig{
-		DockerEndpoint:            r.DockerEndpoint,
-		RuntimeRequestTimeout:     c.RuntimeRequestTimeout.Duration,
-		ImagePullProgressDeadline: r.ImagePullProgressDeadline.Duration,
-	}
-
-	// Initialize network plugin settings.
-	pluginSettings := dockershim.NetworkPluginSettings{
-		HairpinMode:        kubeletconfiginternal.HairpinMode(c.HairpinMode),
-		NonMasqueradeCIDR:  f.NonMasqueradeCIDR,
-		PluginName:         r.NetworkPluginName,
-		PluginConfDir:      r.CNIConfDir,
-		PluginBinDirString: r.CNIBinDir,
-		PluginCacheDir:     r.CNICacheDir,
-		MTU:                int(r.NetworkPluginMTU),
-	}
-
-	// Initialize streaming configuration. (Not using TLS now)
-	streamingConfig := &streaming.Config{
-		// Use a relative redirect (no scheme or host).
-		BaseURL:                         &url.URL{Path: "/cri/"},
-		StreamIdleTimeout:               c.StreamingConnectionIdleTimeout.Duration,
-		StreamCreationTimeout:           streaming.DefaultConfig.StreamCreationTimeout,
-		SupportedRemoteCommandProtocols: streaming.DefaultConfig.SupportedRemoteCommandProtocols,
-		SupportedPortForwardProtocols:   streaming.DefaultConfig.SupportedPortForwardProtocols,
-	}
-
-	// Standalone dockershim will always start the local streaming server.
-	ds, err := dockershim.NewDockerService(dockerClientConfig, r.PodSandboxImage, streamingConfig, &pluginSettings,
-		f.RuntimeCgroups, c.CgroupDriver, r.DockershimRootDirectory, true /*startLocalStreamingServer*/)
-	if err != nil {
-		return err
-	}
-	klog.V(2).Infof("Starting the GRPC server for the docker CRI shim.")
-	server := dockerremote.NewDockerServer(f.RemoteRuntimeEndpoint, ds)
-	if err := server.Start(); err != nil {
-		return err
-	}
-	<-stopCh
-	return nil
-}