| /* |
| Copyright 2014 The Kubernetes Authors. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| package config |
| |
| import ( |
| "fmt" |
| "reflect" |
| "strings" |
| |
| "k8s.io/apimachinery/pkg/util/sets" |
| clientcmdapi "k8s.io/client-go/tools/clientcmd/api" |
| ) |
| |
| type navigationSteps struct { |
| steps []navigationStep |
| currentStepIndex int |
| } |
| |
| type navigationStep struct { |
| stepValue string |
| stepType reflect.Type |
| } |
| |
| func newNavigationSteps(path string) (*navigationSteps, error) { |
| steps := []navigationStep{} |
| individualParts := strings.Split(path, ".") |
| |
| currType := reflect.TypeOf(clientcmdapi.Config{}) |
| currPartIndex := 0 |
| for currPartIndex < len(individualParts) { |
| switch currType.Kind() { |
| case reflect.Map: |
| // if we're in a map, we need to locate a name. That name may contain dots, so we need to know what tokens are legal for the map's value type |
| // for example, we could have a set request like: `set clusters.10.10.12.56.insecure-skip-tls-verify true`. We enter this case with |
| // steps representing 10, 10, 12, 56, insecure-skip-tls-verify. The name is "10.10.12.56", so we want to collect all those parts together and |
| // store them as a single step. In order to do that, we need to determine what set of tokens is a legal step AFTER the name of the map key |
| // This set of reflective code pulls the type of the map values, uses that type to look up the set of legal tags. Those legal tags are used to |
| // walk the list of remaining parts until we find a match to a legal tag or the end of the string. That name is used to burn all the used parts. |
| mapValueType := currType.Elem().Elem() |
| mapValueOptions, err := getPotentialTypeValues(mapValueType) |
| if err != nil { |
| return nil, err |
| } |
| nextPart := findNameStep(individualParts[currPartIndex:], sets.StringKeySet(mapValueOptions)) |
| |
| steps = append(steps, navigationStep{nextPart, mapValueType}) |
| currPartIndex += len(strings.Split(nextPart, ".")) |
| currType = mapValueType |
| |
| case reflect.Struct: |
| nextPart := individualParts[currPartIndex] |
| |
| options, err := getPotentialTypeValues(currType) |
| if err != nil { |
| return nil, err |
| } |
| fieldType, exists := options[nextPart] |
| if !exists { |
| return nil, fmt.Errorf("unable to parse %v after %v at %v", path, steps, currType) |
| } |
| |
| steps = append(steps, navigationStep{nextPart, fieldType}) |
| currPartIndex += len(strings.Split(nextPart, ".")) |
| currType = fieldType |
| } |
| } |
| |
| return &navigationSteps{steps, 0}, nil |
| } |
| |
| func (s *navigationSteps) pop() navigationStep { |
| if s.moreStepsRemaining() { |
| s.currentStepIndex++ |
| return s.steps[s.currentStepIndex-1] |
| } |
| return navigationStep{} |
| } |
| |
| func (s *navigationSteps) peek() navigationStep { |
| if s.moreStepsRemaining() { |
| return s.steps[s.currentStepIndex] |
| } |
| return navigationStep{} |
| } |
| |
| func (s *navigationSteps) moreStepsRemaining() bool { |
| return len(s.steps) > s.currentStepIndex |
| } |
| |
| // findNameStep takes the list of parts and a set of valid tags that can be used after the name. It then walks the list of parts |
| // until it find a valid "next" tag or until it reaches the end of the parts and then builds the name back up out of the individual parts |
| func findNameStep(parts []string, typeOptions sets.String) string { |
| if len(parts) == 0 { |
| return "" |
| } |
| |
| numberOfPartsInStep := findKnownValue(parts[1:], typeOptions) + 1 |
| // if we didn't find a known value, then the entire thing must be a name |
| if numberOfPartsInStep == 0 { |
| numberOfPartsInStep = len(parts) |
| } |
| nextParts := parts[0:numberOfPartsInStep] |
| |
| return strings.Join(nextParts, ".") |
| } |
| |
| // getPotentialTypeValues takes a type and looks up the tags used to represent its fields when serialized. |
| func getPotentialTypeValues(typeValue reflect.Type) (map[string]reflect.Type, error) { |
| if typeValue.Kind() == reflect.Ptr { |
| typeValue = typeValue.Elem() |
| } |
| |
| if typeValue.Kind() != reflect.Struct { |
| return nil, fmt.Errorf("%v is not of type struct", typeValue) |
| } |
| |
| ret := make(map[string]reflect.Type) |
| |
| for fieldIndex := 0; fieldIndex < typeValue.NumField(); fieldIndex++ { |
| fieldType := typeValue.Field(fieldIndex) |
| yamlTag := fieldType.Tag.Get("json") |
| yamlTagName := strings.Split(yamlTag, ",")[0] |
| |
| ret[yamlTagName] = fieldType.Type |
| } |
| |
| return ret, nil |
| } |
| |
| func findKnownValue(parts []string, valueOptions sets.String) int { |
| for i := range parts { |
| if valueOptions.Has(parts[i]) { |
| return i |
| } |
| } |
| |
| return -1 |
| } |