FieldSpec Backward Compatibility with K8s Downward API

k8sdeps/kunstruct/helper.go

@@ -76,10 +76,13 @@ func parseFields(path string) ([]PathSection, error) {
 				// PathSection, save it to the set, then begin
 				// a new PathSection
 				tmpIdx, err := strconv.Atoi(path[start:i])
-				if err != nil {
+				if err == nil {
-					return nil, fmt.Errorf("invalid index %s", path)
+					// We have detected an integer so an array.
-				}
 					section.idx = tmpIdx
+				} else {
+					// We have detected the downwardapi syntax
+					appendNonEmpty(&section, path[start:i])
+				}
 				sectionset = append(sectionset, section)
 				section = newPathSection()
 

k8sdeps/kunstruct/helper_test.go

@@ -94,10 +94,10 @@ func TestParseField(t *testing.T) {
 			errorExpected: false,
 		},
 		{
-			name:          "validStructSubFieldNoneIntIndex",
+			name:          "validStructDownwardAPI",
-			pathToField:   "complextree[thisisnotanint]",
+			pathToField:   `metadata.labels["app.kubernetes.io/component"]`,
-			errorExpected: true,
+			expectedValue: buildPath(-1, "metadata", "labels", "app.kubernetes.io/component"),
-			errorMsg:      "invalid index complextree[thisisnotanint]",
+			errorExpected: false,
 		},
 		{
 			name:          "invalidIndexInIndex",

k8sdeps/kunstruct/kunstruct_test.go

@@ -24,14 +24,14 @@ import (
 var kunstructured = NewKunstructuredFactoryImpl().FromMap(map[string]interface{}{
 	"Kind": "Service",
 	"metadata": map[string]interface{}{
-		"labels": map[string]string{
+		"labels": map[string]interface{}{
 			"app": "application-name",
 		},
 		"name": "service-name",
 	},
 	"spec": map[string]interface{}{
 		"ports": map[string]interface{}{
-			"port": "80",
+			"port": int64(80),
 		},
 	},
 	"this": map[string]interface{}{
@@ -168,7 +168,7 @@ func TestGetFieldValue(t *testing.T) {
 		{
 			name:          "threeFields",
 			pathToField:   "spec.ports.port",
-			expectedValue: "80",
+			expectedValue: int64(80),
 			errorExpected: false,
 		},
 		{
@@ -249,6 +249,12 @@ func TestGetFieldValue(t *testing.T) {
 			errorMsg:      "no field named 'that[99]'",
 			errorExpected: true,
 		},
+		{
+			name:          "accessorError",
+			pathToField:   "that[downwardapi]",
+			errorMsg:      ".that.downwardapi accessor error: [idx0 idx1 idx2 idx3] is of the type []interface {}, expected map[string]interface{}",
+			errorExpected: true,
+		},
 		{
 			name:          "unknownSlice",
 			pathToField:   "unknown[0]",
@@ -298,16 +304,34 @@ func TestGetFieldValue(t *testing.T) {
 			errorMsg:      "no field named 'complextree[1].field2[1].invalidsubfield'",
 		},
 		{
-			name:          "validStructSubFieldNoneIntIndex",
+			name:          "validDownwardAPILabels",
-			pathToField:   "complextree[thisisnotanint]",
+			pathToField:   `metadata.labels["app"]`,
-			errorExpected: true,
+			errorExpected: false,
-			errorMsg:      "no field named 'complextree[thisisnotanint]'",
+			expectedValue: "application-name",
 		},
 		{
-			name:          "invalidNoneIntIndex",
+			name:          "validDownwardAPISpecs",
-			pathToField:   "complextree[thisisnotanint]",
+			pathToField:   `spec.ports['port']`,
+			errorExpected: false,
+			expectedValue: int64(80),
+		},
+		{
+			name:          "validDownwardAPIThis",
+			pathToField:   `this.is[aFloat]`,
+			errorExpected: false,
+			expectedValue: float64(1.001),
+		},
+		{
+			name:          "downwardAPIInvalidLabel",
+			pathToField:   `metadata.labels["theisnotanint"]`,
 			errorExpected: true,
-			errorMsg:      "no field named 'complextree[thisisnotanint]'",
+			errorMsg:      `no field named 'metadata.labels["theisnotanint"]'`,
+		},
+		{
+			name:          "downwardAPIInvalidLabel2",
+			pathToField:   `invalidfield.labels["app"]`,
+			errorExpected: true,
+			errorMsg:      `no field named 'invalidfield.labels["app"]'`,
 		},
 		{
 			name:          "invalidIndexInIndex",
@@ -362,12 +386,6 @@ func TestGetString(t *testing.T) {
 			expectedValue: "service-name",
 			errorExpected: false,
 		},
-		{
-			name:          "threeFields",
-			pathToField:   "spec.ports.port",
-			expectedValue: "80",
-			errorExpected: false,
-		},
 		{
 			name:          "emptyMap",
 			pathToField:   "this.is.anEmptyMap",
@@ -440,6 +458,12 @@ func TestGetString(t *testing.T) {
 			errorExpected: true,
 			errorMsg:      "no field named 'this.is[1].aString'",
 		},
+		{
+			name:          "validDownwardAPIField",
+			pathToField:   `metadata.labels["app"]`,
+			errorExpected: false,
+			expectedValue: "application-name",
+		},
 	}
 
 	for _, test := range tests {
@@ -487,6 +511,12 @@ func TestGetInt64(t *testing.T) {
 			errorExpected: true,
 			errorMsg:      "no field named 'these[1].field2[99]'",
 		},
+		{
+			name:          "validDownwardAPISpecs",
+			pathToField:   `spec.ports['port']`,
+			errorExpected: false,
+			expectedValue: int64(80),
+		},
 	}
 
 	for _, test := range tests {
@@ -522,6 +552,12 @@ func TestGetFloat64(t *testing.T) {
 			errorExpected: false,
 			expectedValue: float64(1.1121),
 		},
+		{
+			name:          "validDownwardAPIThis",
+			pathToField:   `this.is[aFloat]`,
+			errorExpected: false,
+			expectedValue: float64(1.001),
+		},
 		{
 			name:          "twoFieldsOneMissing",
 			pathToField:   "metadata.banana",