Merge pull request #39678 from resouer/extract-resource

Automatic merge from submit-queue (batch tested with PRs 41775, 39678, 42629, 42524, 43028)

Extract resources functions belongs to api/util

Address: extract kubelet resources functions belongs to `pkg/api/v1/resource_helpers.go`

hack/.linted_packages

@@ -178,6 +178,7 @@ pkg/controller/volume/attachdetach/reconciler
 pkg/conversion
 pkg/conversion/queryparams
 pkg/credentialprovider/aws
+pkg/fieldpath
 pkg/fields
 pkg/hyperkube
 pkg/kubelet/api

pkg/api/resource_helpers.go

@@ -17,6 +17,9 @@ limitations under the License.
 package api
 
 import (
+	"fmt"
+	"math"
+	"strconv"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -227,3 +230,41 @@ func PodRequestsAndLimits(pod *Pod) (reqs map[ResourceName]resource.Quantity, li
 	}
 	return
 }
+
+// ExtractContainerResourceValue extracts the value of a resource
+// in an already known container
+func ExtractContainerResourceValue(fs *ResourceFieldSelector, container *Container) (string, error) {
+	divisor := resource.Quantity{}
+	if divisor.Cmp(fs.Divisor) == 0 {
+		divisor = resource.MustParse("1")
+	} else {
+		divisor = fs.Divisor
+	}
+
+	switch fs.Resource {
+	case "limits.cpu":
+		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
+	case "limits.memory":
+		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
+	case "requests.cpu":
+		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
+	case "requests.memory":
+		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
+	}
+
+	return "", fmt.Errorf("unsupported container resource : %v", fs.Resource)
+}
+
+// convertResourceCPUToString converts cpu value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceCPUToString(cpu *resource.Quantity, divisor resource.Quantity) (string, error) {
+	c := int64(math.Ceil(float64(cpu.MilliValue()) / float64(divisor.MilliValue())))
+	return strconv.FormatInt(c, 10), nil
+}
+
+// convertResourceMemoryToString converts memory value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(memory.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}

pkg/api/v1/BUILD

@@ -86,6 +86,7 @@ go_test(
     library = ":go_default_library",
     tags = ["automanaged"],
     deps = [
+        "//vendor:github.com/stretchr/testify/assert",
         "//vendor:k8s.io/apimachinery/pkg/api/equality",
         "//vendor:k8s.io/apimachinery/pkg/api/resource",
         "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",

pkg/api/v1/resource_helpers.go

@@ -17,10 +17,14 @@ limitations under the License.
 package v1
 
 import (
+	"fmt"
+	"math"
+	"strconv"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/kubernetes/pkg/api"
 )
 
 // Returns string version of ResourceName.
@@ -255,3 +259,100 @@ func GetResourceRequest(pod *Pod, resource ResourceName) int64 {
 	}
 	return totalResources
 }
+
+// ExtractResourceValueByContainerName extracts the value of a resource
+// by providing container name
+func ExtractResourceValueByContainerName(fs *ResourceFieldSelector, pod *Pod, containerName string) (string, error) {
+	container, err := findContainerInPod(pod, containerName)
+	if err != nil {
+		return "", err
+	}
+	return ExtractContainerResourceValue(fs, container)
+}
+
+// ExtractResourceValueByContainerNameAndNodeAllocatable extracts the value of a resource
+// by providing container name and node allocatable
+func ExtractResourceValueByContainerNameAndNodeAllocatable(fs *ResourceFieldSelector, pod *Pod, containerName string, nodeAllocatable ResourceList) (string, error) {
+	realContainer, err := findContainerInPod(pod, containerName)
+	if err != nil {
+		return "", err
+	}
+
+	containerCopy, err := api.Scheme.DeepCopy(realContainer)
+	if err != nil {
+		return "", fmt.Errorf("failed to perform a deep copy of container object: %v", err)
+	}
+
+	container, ok := containerCopy.(*Container)
+	if !ok {
+		return "", fmt.Errorf("unexpected type returned from deep copy of container object")
+	}
+
+	MergeContainerResourceLimits(container, nodeAllocatable)
+
+	return ExtractContainerResourceValue(fs, container)
+}
+
+// ExtractContainerResourceValue extracts the value of a resource
+// in an already known container
+func ExtractContainerResourceValue(fs *ResourceFieldSelector, container *Container) (string, error) {
+	divisor := resource.Quantity{}
+	if divisor.Cmp(fs.Divisor) == 0 {
+		divisor = resource.MustParse("1")
+	} else {
+		divisor = fs.Divisor
+	}
+
+	switch fs.Resource {
+	case "limits.cpu":
+		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
+	case "limits.memory":
+		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
+	case "requests.cpu":
+		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
+	case "requests.memory":
+		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
+	}
+
+	return "", fmt.Errorf("Unsupported container resource : %v", fs.Resource)
+}
+
+// convertResourceCPUToString converts cpu value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceCPUToString(cpu *resource.Quantity, divisor resource.Quantity) (string, error) {
+	c := int64(math.Ceil(float64(cpu.MilliValue()) / float64(divisor.MilliValue())))
+	return strconv.FormatInt(c, 10), nil
+}
+
+// convertResourceMemoryToString converts memory value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(memory.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}
+
+// findContainerInPod finds a container by its name in the provided pod
+func findContainerInPod(pod *Pod, containerName string) (*Container, error) {
+	for _, container := range pod.Spec.Containers {
+		if container.Name == containerName {
+			return &container, nil
+		}
+	}
+	return nil, fmt.Errorf("container %s not found", containerName)
+}
+
+// MergeContainerResourceLimits checks if a limit is applied for
+// the container, and if not, it sets the limit to the passed resource list.
+func MergeContainerResourceLimits(container *Container,
+	allocatable ResourceList) {
+	if container.Resources.Limits == nil {
+		container.Resources.Limits = make(ResourceList)
+	}
+	for _, resource := range []ResourceName{ResourceCPU, ResourceMemory} {
+		if quantity, exists := container.Resources.Limits[resource]; !exists || quantity.IsZero() {
+			if cap, exists := allocatable[resource]; exists {
+				container.Resources.Limits[resource] = *cap.Copy()
+			}
+		}
+	}
+}

pkg/api/v1/resource_helpers_test.go

@@ -20,6 +20,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
+
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
@@ -118,3 +120,119 @@ func TestIsPodAvailable(t *testing.T) {
 		}
 	}
 }
+
+func TestExtractResourceValue(t *testing.T) {
+	cases := []struct {
+		fs            *ResourceFieldSelector
+		pod           *Pod
+		cName         string
+		expectedValue string
+		expectedError error
+	}{
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "limits.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "9", "", ""),
+			expectedValue: "9",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "", ""),
+			expectedValue: "0",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "8", "", "", ""),
+			expectedValue: "8",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "100m", "", "", ""),
+			expectedValue: "1",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.cpu",
+				Divisor:  resource.MustParse("100m"),
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "1200m", "", "", ""),
+			expectedValue: "12",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.memory",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "100Mi", ""),
+			expectedValue: "104857600",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "requests.memory",
+				Divisor:  resource.MustParse("1Mi"),
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "100Mi", "1Gi"),
+			expectedValue: "100",
+		},
+		{
+			fs: &ResourceFieldSelector{
+				Resource: "limits.memory",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "10Mi", "100Mi"),
+			expectedValue: "104857600",
+		},
+	}
+	as := assert.New(t)
+	for idx, tc := range cases {
+		actual, err := ExtractResourceValueByContainerName(tc.fs, tc.pod, tc.cName)
+		if tc.expectedError != nil {
+			as.Equal(tc.expectedError, err, "expected test case [%d] to fail with error %v; got %v", idx, tc.expectedError, err)
+		} else {
+			as.Nil(err, "expected test case [%d] to not return an error; got %v", idx, err)
+			as.Equal(tc.expectedValue, actual, "expected test case [%d] to return %q; got %q instead", idx, tc.expectedValue, actual)
+		}
+	}
+}
+
+func getPod(cname, cpuRequest, cpuLimit, memoryRequest, memoryLimit string) *Pod {
+	resources := ResourceRequirements{
+		Limits:   make(ResourceList),
+		Requests: make(ResourceList),
+	}
+	if cpuLimit != "" {
+		resources.Limits[ResourceCPU] = resource.MustParse(cpuLimit)
+	}
+	if memoryLimit != "" {
+		resources.Limits[ResourceMemory] = resource.MustParse(memoryLimit)
+	}
+	if cpuRequest != "" {
+		resources.Requests[ResourceCPU] = resource.MustParse(cpuRequest)
+	}
+	if memoryRequest != "" {
+		resources.Requests[ResourceMemory] = resource.MustParse(memoryRequest)
+	}
+	return &Pod{
+		Spec: PodSpec{
+			Containers: []Container{
+				{
+					Name:      cname,
+					Resources: resources,
+				},
+			},
+		},
+	}
+}

pkg/fieldpath/BUILD

@@ -15,12 +15,7 @@ go_library(
         "fieldpath.go",
     ],
     tags = ["automanaged"],
-    deps = [
+    deps = ["//vendor:k8s.io/apimachinery/pkg/api/meta"],
-        "//pkg/api:go_default_library",
-        "//pkg/api/v1:go_default_library",
-        "//vendor:k8s.io/apimachinery/pkg/api/meta",
-        "//vendor:k8s.io/apimachinery/pkg/api/resource",
-    ],
 )
 
 go_test(
@@ -30,8 +25,6 @@ go_test(
     tags = ["automanaged"],
     deps = [
         "//pkg/api/v1:go_default_library",
-        "//vendor:github.com/stretchr/testify/assert",
-        "//vendor:k8s.io/apimachinery/pkg/api/resource",
         "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",
     ],
 )

pkg/fieldpath/fieldpath.go

@@ -18,14 +18,9 @@ package fieldpath
 
 import (
 	"fmt"
-	"math"
-	"strconv"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/api/meta"
-	"k8s.io/apimachinery/pkg/api/resource"
-	"k8s.io/kubernetes/pkg/api"
-	"k8s.io/kubernetes/pkg/api/v1"
 )
 
 // FormatMap formats map[string]string to a string.
@@ -60,126 +55,3 @@ func ExtractFieldPathAsString(obj interface{}, fieldPath string) (string, error)
 
 	return "", fmt.Errorf("unsupported fieldPath: %v", fieldPath)
 }
-
-// TODO: move the functions below to pkg/api/util/resources
-// ExtractResourceValueByContainerName extracts the value of a resource
-// by providing container name
-func ExtractResourceValueByContainerName(fs *v1.ResourceFieldSelector, pod *v1.Pod, containerName string) (string, error) {
-	container, err := findContainerInPod(pod, containerName)
-	if err != nil {
-		return "", err
-	}
-	return ExtractContainerResourceValue(fs, container)
-}
-
-// ExtractResourceValueByContainerNameAndNodeAllocatable extracts the value of a resource
-// by providing container name and node allocatable
-func ExtractResourceValueByContainerNameAndNodeAllocatable(fs *v1.ResourceFieldSelector, pod *v1.Pod, containerName string, nodeAllocatable v1.ResourceList) (string, error) {
-	realContainer, err := findContainerInPod(pod, containerName)
-	if err != nil {
-		return "", err
-	}
-
-	containerCopy, err := api.Scheme.DeepCopy(realContainer)
-	if err != nil {
-		return "", fmt.Errorf("failed to perform a deep copy of container object: %v", err)
-	}
-
-	container, ok := containerCopy.(*v1.Container)
-	if !ok {
-		return "", fmt.Errorf("unexpected type returned from deep copy of container object")
-	}
-
-	MergeContainerResourceLimits(container, nodeAllocatable)
-
-	return ExtractContainerResourceValue(fs, container)
-}
-
-// ExtractContainerResourceValue extracts the value of a resource
-// in an already known container
-func ExtractContainerResourceValue(fs *v1.ResourceFieldSelector, container *v1.Container) (string, error) {
-	divisor := resource.Quantity{}
-	if divisor.Cmp(fs.Divisor) == 0 {
-		divisor = resource.MustParse("1")
-	} else {
-		divisor = fs.Divisor
-	}
-
-	switch fs.Resource {
-	case "limits.cpu":
-		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
-	case "limits.memory":
-		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
-	case "requests.cpu":
-		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
-	case "requests.memory":
-		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
-	}
-
-	return "", fmt.Errorf("Unsupported container resource : %v", fs.Resource)
-}
-
-// TODO: remove this duplicate
-// InternalExtractContainerResourceValue extracts the value of a resource
-// in an already known container
-func InternalExtractContainerResourceValue(fs *api.ResourceFieldSelector, container *api.Container) (string, error) {
-	divisor := resource.Quantity{}
-	if divisor.Cmp(fs.Divisor) == 0 {
-		divisor = resource.MustParse("1")
-	} else {
-		divisor = fs.Divisor
-	}
-
-	switch fs.Resource {
-	case "limits.cpu":
-		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
-	case "limits.memory":
-		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
-	case "requests.cpu":
-		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
-	case "requests.memory":
-		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
-	}
-
-	return "", fmt.Errorf("unsupported container resource : %v", fs.Resource)
-}
-
-// findContainerInPod finds a container by its name in the provided pod
-func findContainerInPod(pod *v1.Pod, containerName string) (*v1.Container, error) {
-	for _, container := range pod.Spec.Containers {
-		if container.Name == containerName {
-			return &container, nil
-		}
-	}
-	return nil, fmt.Errorf("container %s not found", containerName)
-}
-
-// convertResourceCPUToString converts cpu value to the format of divisor and returns
-// ceiling of the value.
-func convertResourceCPUToString(cpu *resource.Quantity, divisor resource.Quantity) (string, error) {
-	c := int64(math.Ceil(float64(cpu.MilliValue()) / float64(divisor.MilliValue())))
-	return strconv.FormatInt(c, 10), nil
-}
-
-// convertResourceMemoryToString converts memory value to the format of divisor and returns
-// ceiling of the value.
-func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Quantity) (string, error) {
-	m := int64(math.Ceil(float64(memory.Value()) / float64(divisor.Value())))
-	return strconv.FormatInt(m, 10), nil
-}
-
-// MergeContainerResourceLimits checks if a limit is applied for
-// the container, and if not, it sets the limit to the passed resource list.
-func MergeContainerResourceLimits(container *v1.Container,
-	allocatable v1.ResourceList) {
-	if container.Resources.Limits == nil {
-		container.Resources.Limits = make(v1.ResourceList)
-	}
-	for _, resource := range []v1.ResourceName{v1.ResourceCPU, v1.ResourceMemory} {
-		if quantity, exists := container.Resources.Limits[resource]; !exists || quantity.IsZero() {
-			if cap, exists := allocatable[resource]; exists {
-				container.Resources.Limits[resource] = *cap.Copy()
-			}
-		}
-	}
-}

pkg/fieldpath/fieldpath_test.go

@@ -20,9 +20,6 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/stretchr/testify/assert"
-
-	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/kubernetes/pkg/api/v1"
 )
@@ -119,119 +116,3 @@ func TestExtractFieldPathAsString(t *testing.T) {
 		}
 	}
 }
-
-func getPod(cname, cpuRequest, cpuLimit, memoryRequest, memoryLimit string) *v1.Pod {
-	resources := v1.ResourceRequirements{
-		Limits:   make(v1.ResourceList),
-		Requests: make(v1.ResourceList),
-	}
-	if cpuLimit != "" {
-		resources.Limits[v1.ResourceCPU] = resource.MustParse(cpuLimit)
-	}
-	if memoryLimit != "" {
-		resources.Limits[v1.ResourceMemory] = resource.MustParse(memoryLimit)
-	}
-	if cpuRequest != "" {
-		resources.Requests[v1.ResourceCPU] = resource.MustParse(cpuRequest)
-	}
-	if memoryRequest != "" {
-		resources.Requests[v1.ResourceMemory] = resource.MustParse(memoryRequest)
-	}
-	return &v1.Pod{
-		Spec: v1.PodSpec{
-			Containers: []v1.Container{
-				{
-					Name:      cname,
-					Resources: resources,
-				},
-			},
-		},
-	}
-}
-
-func TestExtractResourceValue(t *testing.T) {
-	cases := []struct {
-		fs            *v1.ResourceFieldSelector
-		pod           *v1.Pod
-		cName         string
-		expectedValue string
-		expectedError error
-	}{
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "limits.cpu",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "", "9", "", ""),
-			expectedValue: "9",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.cpu",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "", "", "", ""),
-			expectedValue: "0",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.cpu",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "8", "", "", ""),
-			expectedValue: "8",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.cpu",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "100m", "", "", ""),
-			expectedValue: "1",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.cpu",
-				Divisor:  resource.MustParse("100m"),
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "1200m", "", "", ""),
-			expectedValue: "12",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.memory",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "", "", "100Mi", ""),
-			expectedValue: "104857600",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "requests.memory",
-				Divisor:  resource.MustParse("1Mi"),
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "", "", "100Mi", "1Gi"),
-			expectedValue: "100",
-		},
-		{
-			fs: &v1.ResourceFieldSelector{
-				Resource: "limits.memory",
-			},
-			cName:         "foo",
-			pod:           getPod("foo", "", "", "10Mi", "100Mi"),
-			expectedValue: "104857600",
-		},
-	}
-	as := assert.New(t)
-	for idx, tc := range cases {
-		actual, err := ExtractResourceValueByContainerName(tc.fs, tc.pod, tc.cName)
-		if tc.expectedError != nil {
-			as.Equal(tc.expectedError, err, "expected test case [%d] to fail with error %v; got %v", idx, tc.expectedError, err)
-		} else {
-			as.Nil(err, "expected test case [%d] to not return an error; got %v", idx, err)
-			as.Equal(tc.expectedValue, actual, "expected test case [%d] to return %q; got %q instead", idx, tc.expectedValue, actual)
-		}
-	}
-}

pkg/kubelet/kubelet_pods.go

@@ -654,9 +654,9 @@ func (kl *Kubelet) podFieldSelectorRuntimeValue(fs *v1.ObjectFieldSelector, pod
 func containerResourceRuntimeValue(fs *v1.ResourceFieldSelector, pod *v1.Pod, container *v1.Container) (string, error) {
 	containerName := fs.ContainerName
 	if len(containerName) == 0 {
-		return fieldpath.ExtractContainerResourceValue(fs, container)
+		return v1.ExtractContainerResourceValue(fs, container)
 	} else {
-		return fieldpath.ExtractResourceValueByContainerName(fs, pod, containerName)
+		return v1.ExtractResourceValueByContainerName(fs, pod, containerName)
 	}
 }
 

pkg/kubelet/kubelet_resources.go

@@ -23,7 +23,6 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/v1"
-	"k8s.io/kubernetes/pkg/fieldpath"
 )
 
 // defaultPodLimitsForDownwardApi copies the input pod, and optional container,
@@ -53,7 +52,7 @@ func (kl *Kubelet) defaultPodLimitsForDownwardApi(pod *v1.Pod, container *v1.Con
 		return nil, nil, fmt.Errorf("unexpected type returned from deep copy of pod object")
 	}
 	for idx := range outputPod.Spec.Containers {
-		fieldpath.MergeContainerResourceLimits(&outputPod.Spec.Containers[idx], allocatable)
+		v1.MergeContainerResourceLimits(&outputPod.Spec.Containers[idx], allocatable)
 	}
 
 	var outputContainer *v1.Container
@@ -66,7 +65,7 @@ func (kl *Kubelet) defaultPodLimitsForDownwardApi(pod *v1.Pod, container *v1.Con
 		if !ok {
 			return nil, nil, fmt.Errorf("unexpected type returned from deep copy of container object")
 		}
-		fieldpath.MergeContainerResourceLimits(outputContainer, allocatable)
+		v1.MergeContainerResourceLimits(outputContainer, allocatable)
 	}
 	return outputPod, outputContainer, nil
 }

pkg/printers/internalversion/describe.go

@@ -1100,7 +1100,7 @@ func describeContainerEnvVars(container api.Container, resolverFn EnvVarResolver
 			}
 			w.Write(LEVEL_3, "%s:\t%s (%s:%s)\n", e.Name, valueFrom, e.ValueFrom.FieldRef.APIVersion, e.ValueFrom.FieldRef.FieldPath)
 		case e.ValueFrom.ResourceFieldRef != nil:
-			valueFrom, err := fieldpath.InternalExtractContainerResourceValue(e.ValueFrom.ResourceFieldRef, &container)
+			valueFrom, err := api.ExtractContainerResourceValue(e.ValueFrom.ResourceFieldRef, &container)
 			if err != nil {
 				valueFrom = ""
 			}

pkg/volume/downwardapi/downwardapi.go

@@ -244,7 +244,7 @@ func CollectData(items []v1.DownwardAPIVolumeFile, pod *v1.Pod, host volume.Volu
 			nodeAllocatable, err := host.GetNodeAllocatable()
 			if err != nil {
 				errlist = append(errlist, err)
-			} else if values, err := fieldpath.ExtractResourceValueByContainerNameAndNodeAllocatable(fileInfo.ResourceFieldRef, pod, containerName, nodeAllocatable); err != nil {
+			} else if values, err := v1.ExtractResourceValueByContainerNameAndNodeAllocatable(fileInfo.ResourceFieldRef, pod, containerName, nodeAllocatable); err != nil {
 				glog.Errorf("Unable to extract field %s: %s", fileInfo.ResourceFieldRef.Resource, err.Error())
 				errlist = append(errlist, err)
 			} else {

staging/src/k8s.io/client-go/pkg/api/resource_helpers.go

@@ -17,6 +17,9 @@ limitations under the License.
 package api
 
 import (
+	"fmt"
+	"math"
+	"strconv"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -227,3 +230,41 @@ func PodRequestsAndLimits(pod *Pod) (reqs map[ResourceName]resource.Quantity, li
 	}
 	return
 }
+
+// ExtractContainerResourceValue extracts the value of a resource
+// in an already known container
+func ExtractContainerResourceValue(fs *ResourceFieldSelector, container *Container) (string, error) {
+	divisor := resource.Quantity{}
+	if divisor.Cmp(fs.Divisor) == 0 {
+		divisor = resource.MustParse("1")
+	} else {
+		divisor = fs.Divisor
+	}
+
+	switch fs.Resource {
+	case "limits.cpu":
+		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
+	case "limits.memory":
+		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
+	case "requests.cpu":
+		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
+	case "requests.memory":
+		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
+	}
+
+	return "", fmt.Errorf("unsupported container resource : %v", fs.Resource)
+}
+
+// convertResourceCPUToString converts cpu value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceCPUToString(cpu *resource.Quantity, divisor resource.Quantity) (string, error) {
+	c := int64(math.Ceil(float64(cpu.MilliValue()) / float64(divisor.MilliValue())))
+	return strconv.FormatInt(c, 10), nil
+}
+
+// convertResourceMemoryToString converts memory value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(memory.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}

staging/src/k8s.io/client-go/pkg/api/v1/resource_helpers.go

@@ -17,10 +17,14 @@ limitations under the License.
 package v1
 
 import (
+	"fmt"
+	"math"
+	"strconv"
 	"time"
 
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/pkg/api"
 )
 
 // Returns string version of ResourceName.
@@ -255,3 +259,100 @@ func GetResourceRequest(pod *Pod, resource ResourceName) int64 {
 	}
 	return totalResources
 }
+
+// ExtractResourceValueByContainerName extracts the value of a resource
+// by providing container name
+func ExtractResourceValueByContainerName(fs *ResourceFieldSelector, pod *Pod, containerName string) (string, error) {
+	container, err := findContainerInPod(pod, containerName)
+	if err != nil {
+		return "", err
+	}
+	return ExtractContainerResourceValue(fs, container)
+}
+
+// ExtractResourceValueByContainerNameAndNodeAllocatable extracts the value of a resource
+// by providing container name and node allocatable
+func ExtractResourceValueByContainerNameAndNodeAllocatable(fs *ResourceFieldSelector, pod *Pod, containerName string, nodeAllocatable ResourceList) (string, error) {
+	realContainer, err := findContainerInPod(pod, containerName)
+	if err != nil {
+		return "", err
+	}
+
+	containerCopy, err := api.Scheme.DeepCopy(realContainer)
+	if err != nil {
+		return "", fmt.Errorf("failed to perform a deep copy of container object: %v", err)
+	}
+
+	container, ok := containerCopy.(*Container)
+	if !ok {
+		return "", fmt.Errorf("unexpected type returned from deep copy of container object")
+	}
+
+	MergeContainerResourceLimits(container, nodeAllocatable)
+
+	return ExtractContainerResourceValue(fs, container)
+}
+
+// ExtractContainerResourceValue extracts the value of a resource
+// in an already known container
+func ExtractContainerResourceValue(fs *ResourceFieldSelector, container *Container) (string, error) {
+	divisor := resource.Quantity{}
+	if divisor.Cmp(fs.Divisor) == 0 {
+		divisor = resource.MustParse("1")
+	} else {
+		divisor = fs.Divisor
+	}
+
+	switch fs.Resource {
+	case "limits.cpu":
+		return convertResourceCPUToString(container.Resources.Limits.Cpu(), divisor)
+	case "limits.memory":
+		return convertResourceMemoryToString(container.Resources.Limits.Memory(), divisor)
+	case "requests.cpu":
+		return convertResourceCPUToString(container.Resources.Requests.Cpu(), divisor)
+	case "requests.memory":
+		return convertResourceMemoryToString(container.Resources.Requests.Memory(), divisor)
+	}
+
+	return "", fmt.Errorf("Unsupported container resource : %v", fs.Resource)
+}
+
+// convertResourceCPUToString converts cpu value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceCPUToString(cpu *resource.Quantity, divisor resource.Quantity) (string, error) {
+	c := int64(math.Ceil(float64(cpu.MilliValue()) / float64(divisor.MilliValue())))
+	return strconv.FormatInt(c, 10), nil
+}
+
+// convertResourceMemoryToString converts memory value to the format of divisor and returns
+// ceiling of the value.
+func convertResourceMemoryToString(memory *resource.Quantity, divisor resource.Quantity) (string, error) {
+	m := int64(math.Ceil(float64(memory.Value()) / float64(divisor.Value())))
+	return strconv.FormatInt(m, 10), nil
+}
+
+// findContainerInPod finds a container by its name in the provided pod
+func findContainerInPod(pod *Pod, containerName string) (*Container, error) {
+	for _, container := range pod.Spec.Containers {
+		if container.Name == containerName {
+			return &container, nil
+		}
+	}
+	return nil, fmt.Errorf("container %s not found", containerName)
+}
+
+// MergeContainerResourceLimits checks if a limit is applied for
+// the container, and if not, it sets the limit to the passed resource list.
+func MergeContainerResourceLimits(container *Container,
+	allocatable ResourceList) {
+	if container.Resources.Limits == nil {
+		container.Resources.Limits = make(ResourceList)
+	}
+	for _, resource := range []ResourceName{ResourceCPU, ResourceMemory} {
+		if quantity, exists := container.Resources.Limits[resource]; !exists || quantity.IsZero() {
+			if cap, exists := allocatable[resource]; exists {
+				container.Resources.Limits[resource] = *cap.Copy()
+			}
+		}
+	}
+}