Use preload tarball for VMs

Since preloaded tarballs are container runtime specific, I added a Preload() func
to the cruntime interface. To use  it with VMs, the tarball is first
copied into the VM and then extracted. The leftover tarball is deleted,
and the container runtime (currently only docker is supported) is
restarted.

pkg/minikube/cruntime/containerd.go

@@ -308,3 +308,8 @@ func (r *Containerd) ContainerLogCmd(id string, len int, follow bool) string {
 func (r *Containerd) SystemLogCmd(len int) string {
 	return fmt.Sprintf("sudo journalctl -u containerd -n %d", len)
 }
+
+// Preload preloads the container runtime with k8s images
+func (r *Containerd) Preload(k8sVersion string) error {
+	return nil
+}

pkg/minikube/cruntime/crio.go

@@ -225,3 +225,8 @@ func (r *CRIO) ContainerLogCmd(id string, len int, follow bool) string {
 func (r *CRIO) SystemLogCmd(len int) string {
 	return fmt.Sprintf("sudo journalctl -u crio -n %d", len)
 }
+
+// Preload preloads the container runtime with k8s images
+func (r *CRIO) Preload(k8sVersion string) error {
+	return nil
+}

pkg/minikube/cruntime/cruntime.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/golang/glog"
 	"github.com/pkg/errors"
+	"k8s.io/minikube/pkg/minikube/assets"
 	"k8s.io/minikube/pkg/minikube/command"
 	"k8s.io/minikube/pkg/minikube/out"
 )
@@ -46,6 +47,8 @@ func (cs ContainerState) String() string {
 // CommandRunner is the subset of command.Runner this package consumes
 type CommandRunner interface {
 	RunCmd(cmd *exec.Cmd) (*command.RunResult, error)
+	// Copy is a convenience method that runs a command to copy a file
+	Copy(assets.CopyableFile) error
 }
 
 // Manager is a common interface for container runtimes
@@ -94,6 +97,8 @@ type Manager interface {
 	ContainerLogCmd(string, int, bool) string
 	// SystemLogCmd returns the command to return the system logs
 	SystemLogCmd(int) string
+	// Preload preloads the container runtime with k8s images
+	Preload(string) error
 }
 
 // Config is runtime configuration

pkg/minikube/cruntime/docker.go

@@ -19,11 +19,15 @@ package cruntime
 import (
 	"fmt"
 	"os/exec"
+	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/golang/glog"
 	"github.com/pkg/errors"
+	"k8s.io/minikube/pkg/minikube/assets"
 	"k8s.io/minikube/pkg/minikube/out"
+	"k8s.io/minikube/pkg/minikube/preload"
 )
 
 // KubernetesContainerPrefix is the prefix of each kubernetes container
@@ -93,6 +97,15 @@ func (r *Docker) Enable(disOthers bool) error {
 	return nil
 }
 
+// Restart restarts Docker on a host
+func (r *Docker) Restart() error {
+	c := exec.Command("sudo", "systemctl", "restart", "docker")
+	if _, err := r.Runner.RunCmd(c); err != nil {
+		return errors.Wrap(err, "restarting docker.")
+	}
+	return nil
+}
+
 // Disable idempotently disables Docker on a host
 func (r *Docker) Disable() error {
 	c := exec.Command("sudo", "systemctl", "stop", "docker", "docker.socket")
@@ -252,3 +265,34 @@ func (r *Docker) ContainerLogCmd(id string, len int, follow bool) string {
 func (r *Docker) SystemLogCmd(len int) string {
 	return fmt.Sprintf("sudo journalctl -u docker -n %d", len)
 }
+
+// Preload preloads docker with k8s images:
+// 1. Copy over the preloaded tarball into the VM
+// 2. Extract the preloaded tarball to the correct directory
+// 3. Remove the tarball within the VM
+func (r *Docker) Preload(k8sVersion string) error {
+	tarballPath := preload.TarballFilepath(k8sVersion)
+	dest := "/tmp/preloaded.tar"
+
+	// Copy over tarball into host
+	fa, err := assets.NewFileAsset(tarballPath, filepath.Dir(dest), filepath.Base(dest), "0644")
+	if err != nil {
+		return errors.Wrap(err, "getting file asset")
+	}
+	t := time.Now()
+	if err := r.Runner.Copy(fa); err != nil {
+		return errors.Wrap(err, "copying file")
+	}
+	glog.Infof("Took %f seconds to copy over tarball", time.Since(t).Seconds())
+
+	// extract the tarball to /var in the VM
+	if rr, err := r.Runner.RunCmd(exec.Command("sudo", "tar", "-I", "lz4", "-C", "/var", "-xvf", dest)); err != nil {
+		return errors.Wrapf(err, "extracting tarball: %s", rr.Output())
+	}
+
+	//  remove the tarball in the VM
+	if rr, err := r.Runner.RunCmd(exec.Command("sudo", "rm", dest)); err != nil {
+		return errors.Wrapf(err, "removing tarball: %s", rr.Output())
+	}
+	return r.Restart()
+}

pkg/minikube/node/config.go

@@ -65,6 +65,9 @@ func configureRuntimes(runner cruntime.CommandRunner, drvName string, k8s config
 	if driver.BareMetal(drvName) {
 		disableOthers = false
 	}
+	if err := cr.Preload(k8s.KubernetesVersion); err != nil {
+		glog.Infof("Failed to preload container runtime %s: %v", cr.Name(), err)
+	}
 	err = cr.Enable(disableOthers)
 	if err != nil {
 		exit.WithError("Failed to enable container runtime", err)

pkg/minikube/node/start.go

@@ -19,7 +19,6 @@ package node
 import (
 	"os"
 
-	"github.com/golang/glog"
 	"github.com/spf13/viper"
 	"golang.org/x/sync/errgroup"
 	"k8s.io/minikube/pkg/addons"
@@ -65,12 +64,6 @@ func Start(mc config.ClusterConfig, n config.Node, primary bool, existingAddons
 	mRunner, preExists, machineAPI, host := startMachine(&mc, &n)
 	defer machineAPI.Close()
 
-	if !driver.IsKIC(driverName) {
-		if err := preload.CopyIntoVMAndExtract(mc, mRunner); err != nil {
-			glog.Infof("error extracting preloaded images to VM: %v", err)
-		}
-	}
-
 	// configure the runtime (docker, containerd, crio)
 	cr := configureRuntimes(mRunner, driverName, mc.KubernetesConfig)
 	showVersionInfo(k8sVersion, cr)

pkg/minikube/preload/preload.go

@@ -23,10 +23,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"os"
-	"os/exec"
 	"path"
-	"path/filepath"
-	"time"
 
 	"cloud.google.com/go/storage"
 	"google.golang.org/api/option"
@@ -34,9 +31,6 @@ import (
 	"github.com/golang/glog"
 	"github.com/hashicorp/go-getter"
 	"github.com/pkg/errors"
-	"k8s.io/minikube/pkg/minikube/assets"
-	"k8s.io/minikube/pkg/minikube/command"
-	"k8s.io/minikube/pkg/minikube/config"
 	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/localpath"
 	"k8s.io/minikube/pkg/minikube/out"
@@ -163,40 +157,3 @@ func verifyChecksum(k8sVersion string) error {
 	}
 	return nil
 }
-
-// CopyIntoVMAndExtract tries to:
-// 1. Copy over the preloaded tarball into the VM
-// 2. Extract the preloaded tarball to the correct directory
-// 3. Remove the tarball within the VM
-func CopyIntoVMAndExtract(cc config.ClusterConfig, runner command.Runner) error {
-	k8sVersion := cc.KubernetesConfig.KubernetesVersion
-	tarballPath := TarballFilepath(k8sVersion)
-	dest := "/tmp/preloaded.tar"
-
-	// Copy over tarball into host
-	fa, err := assets.NewFileAsset(tarballPath, filepath.Dir(dest), filepath.Base(dest), "0644")
-	if err != nil {
-		return errors.Wrap(err, "getting file asset")
-	}
-	t := time.Now()
-	if err := runner.Copy(fa); err != nil {
-		return errors.Wrap(err, "copying file")
-	}
-	glog.Infof("Took %f seconds to copy over tarball", time.Since(t).Seconds())
-
-	// Now, extract the tarball
-	if rr, err := runner.RunCmd(exec.Command("sudo", "tar", "-I", "lz4", "-C", "/var", "-xvf", dest)); err != nil {
-		return errors.Wrapf(err, "extracting tarball: %s", rr.Output())
-	}
-
-	//  remove the tarball on the host
-	if rr, err := runner.RunCmd(exec.Command("sudo", "rm", dest)); err != nil {
-		return errors.Wrapf(err, "removing tarball: %s", rr.Output())
-	}
-
-	// restart the docker daemon
-	if rr, err := runner.RunCmd(exec.Command("sudo", "systemctl", "restart", "docker")); err != nil {
-		return errors.Wrapf(err, "removing tarball: %s", rr.Output())
-	}
-	return fmt.Errorf("error extracting preloaded tarball")
-}