Implemented logic "Add if not exist"

pkg/engine/overlay.go

@@ -113,10 +113,11 @@ func applyOverlayToMap(resourceMap, overlayMap map[string]interface{}, path stri
 			continue
 		}
 
-		currentPath := path + key + "/"
-		resourcePart, ok := resourceMap[key]
+		noAnchorKey := removeAnchor(key)
+		currentPath := path + noAnchorKey + "/"
+		resourcePart, ok := resourceMap[noAnchorKey]
 
-		if ok {
+		if ok && !isAddingAnchor(key) {
 			// Key exists - go down through the overlay and resource trees
 			patches, res := applyOverlay(resourcePart, value, currentPath)
 			overlayResult.MergeWith(&res)
@@ -124,7 +125,9 @@ func applyOverlayToMap(resourceMap, overlayMap map[string]interface{}, path stri
 			if result.Success == overlayResult.GetReason() {
 				appliedPatches = append(appliedPatches, patches...)
 			}
-		} else {
+		}
+
+		if !ok {
 			// Key does not exist - insert entire overlay subtree
 			patch, res := insertSubtree(value, currentPath)
 			overlayResult.MergeWith(&res)

pkg/engine/overlay_test.go

@@ -430,3 +430,46 @@ func TestApplyOverlay_ImagePullPolicy(t *testing.T) {
 
 	compareJsonAsMap(t, expectedResult, doc)
 }
+
+func TestApplyOverlay_AddingAnchor(t *testing.T) {
+	overlayRaw := []byte(`{
+		"metadata": {
+			"name": "nginx-deployment",
+			"labels": {
+				"+(app)": "should-not-be-here",
+				"+(key1)": "value1"
+			}
+		}
+	}`)
+	resourceRaw := []byte(`{
+		"metadata": {
+			"name": "nginx-deployment",
+			"labels": {
+				"app": "nginx"
+			}
+		}
+	}`)
+
+	var resource, overlay interface{}
+
+	json.Unmarshal(resourceRaw, &resource)
+	json.Unmarshal(overlayRaw, &overlay)
+
+	patches, res := applyOverlay(resource, overlay, "/")
+	assert.NilError(t, res.ToError())
+	assert.Assert(t, len(patches) != 0)
+
+	doc, err := ApplyPatches(resourceRaw, patches)
+	assert.NilError(t, err)
+	expectedResult := []byte(`{  
+		"metadata":{  
+		   "labels":{  
+			  "app":"nginx",
+			  "key1":"value1"
+		   },
+		   "name":"nginx-deployment"
+		}
+	 }`)
+
+	compareJsonAsMap(t, expectedResult, doc)
+}

pkg/engine/utils.go

@@ -138,6 +138,17 @@ func wrappedWithParentheses(str string) bool {
 	return (str[0] == '(' && str[len(str)-1] == ')')
 }
 
+func isAddingAnchor(key string) bool {
+	const left = "+("
+	const right = ")"
+
+	if len(key) < len(left)+len(right) {
+		return false
+	}
+
+	return left == key[:len(left)] && right == key[len(key)-len(right):]
+}
+
 // Checks if array object matches anchors. If not - skip - return true
 func skipArrayObject(object, anchors map[string]interface{}) bool {
 	for key, pattern := range anchors {
@@ -162,7 +173,9 @@ func removeAnchor(key string) string {
 		return key[1 : len(key)-1]
 	}
 
-	// TODO: Add logic for other anchors here
+	if isAddingAnchor(key) {
+		return key[2 : len(key)-1]
+	}
 
 	return key
 }