Merge pull request #27441 from derekwaynecarr/downward_api_node_defaults

Automatic merge from submit-queue

Revert revert of downward api node defaults

Reverts the revert of https://github.com/kubernetes/kubernetes/pull/27439

Fixes #27062

@dchen1107 - who at Google can help debug why this caused issues with GKE infrastructure but not GCE merge queue?

/cc @wojtek-t @piosz @fgrzadkowski @eparis @pmorie

pkg/fieldpath/fieldpath_test.go

@@ -20,7 +20,10 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+
 	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/resource"
 )
 
 func TestExtractFieldPathAsString(t *testing.T) {
@@ -115,3 +118,119 @@ func TestExtractFieldPathAsString(t *testing.T) {
 		}
 	}
 }
+
+func getPod(cname, cpuRequest, cpuLimit, memoryRequest, memoryLimit string) *api.Pod {
+	resources := api.ResourceRequirements{
+		Limits:   make(api.ResourceList),
+		Requests: make(api.ResourceList),
+	}
+	if cpuLimit != "" {
+		resources.Limits[api.ResourceCPU] = resource.MustParse(cpuLimit)
+	}
+	if memoryLimit != "" {
+		resources.Limits[api.ResourceMemory] = resource.MustParse(memoryLimit)
+	}
+	if cpuRequest != "" {
+		resources.Requests[api.ResourceCPU] = resource.MustParse(cpuRequest)
+	}
+	if memoryRequest != "" {
+		resources.Requests[api.ResourceMemory] = resource.MustParse(memoryRequest)
+	}
+	return &api.Pod{
+		Spec: api.PodSpec{
+			Containers: []api.Container{
+				{
+					Name:      cname,
+					Resources: resources,
+				},
+			},
+		},
+	}
+}
+
+func TestExtractResourceValue(t *testing.T) {
+	cases := []struct {
+		fs            *api.ResourceFieldSelector
+		pod           *api.Pod
+		cName         string
+		expectedValue string
+		expectedError error
+	}{
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "limits.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "9", "", ""),
+			expectedValue: "9",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "", ""),
+			expectedValue: "0",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "8", "", "", ""),
+			expectedValue: "8",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.cpu",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "100m", "", "", ""),
+			expectedValue: "1",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.cpu",
+				Divisor:  resource.MustParse("100m"),
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "1200m", "", "", ""),
+			expectedValue: "12",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.memory",
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "100Mi", ""),
+			expectedValue: "104857600",
+		},
+		{
+			fs: &api.ResourceFieldSelector{
+				Resource: "requests.memory",
+				Divisor:  resource.MustParse("1Mi"),
+			},
+			cName:         "foo",
+			pod:           getPod("foo", "", "", "100Mi", "1Gi"),
+			expectedValue: "100",
+		},
+		{
+			fs: &api.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)
+		}
+	}
+}