Various fixes to enable kubelet to switch to kuberuntime/dockershim

pkg/kubelet/kuberuntime/kuberuntime_image.go

@@ -17,8 +17,6 @@ limitations under the License.
 package kuberuntime
 
 import (
-	"fmt"
-
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/credentialprovider"
@@ -130,7 +128,8 @@ func (m *kubeGenericRuntimeManager) RemoveImage(image kubecontainer.ImageSpec) e
 }
 
 // ImageStats returns the statistics of the image.
+// TODO: Implement this function.
 func (m *kubeGenericRuntimeManager) ImageStats() (*kubecontainer.ImageStats, error) {
-	// TODO: support image stats in new runtime interface
-	return nil, fmt.Errorf("not implemented")
+	var usageBytes uint64 = 0
+	return &kubecontainer.ImageStats{TotalStorageBytes: usageBytes}, nil
 }

pkg/kubelet/sysctl/runtime.go

@@ -27,6 +27,10 @@ import (
 
 const (
 	UnsupportedReason = "SysctlUnsupported"
+	// CRI uses semver-compatible API version, while docker does not
+	// (e.g., 1.24). Append the version with a ".0" so that it works
+	// with both the CRI and dockertools comparison logic.
+	dockerMinimumAPIVersion = "1.24.0"
 )
 
 type runtimeAdmitHandler struct {
@@ -45,7 +49,7 @@ func NewRuntimeAdmitHandler(runtime container.Runtime) (*runtimeAdmitHandler, er
 		}
 
 		// only Docker >= 1.12 supports sysctls
-		c, err := v.Compare(dockertools.DockerV112APIVersion)
+		c, err := v.Compare(dockerMinimumAPIVersion)
 		if err != nil {
 			return nil, fmt.Errorf("failed to compare Docker version for sysctl support: %v", err)
 		}