github.com/galamsiva2020/kubernetes-heapster-monitoring@v0.0.0-20210823134957-3c1baa7c1e70/metrics/util/label_copier.go (about) 1 // Copyright 2015 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package util 16 17 import ( 18 "fmt" 19 "k8s.io/heapster/metrics/core" 20 "sort" 21 "strings" 22 ) 23 24 // LabelCopier maps kubernetes objects' labels to metrics 25 type LabelCopier struct { 26 // labelSeparator contains separator used to join labels into "labels" label 27 labelSeparator string 28 // storedLabels maps source label names to their destination names used in metrics 29 storedLabels map[string]string 30 // ignoredLabels contains labels to be skipped during concatenation 31 ignoredLabels map[string]string 32 } 33 34 // Copy copies the given set of pod labels into a set of metric labels, using the following logic: 35 // - all labels, unless found in ignoredLabels, are concatenated into a Separator-separated key:value pairs and stored under core.LabelLabels.Key 36 // - labels found in storedLabels are additionally stored under key provided 37 func (this *LabelCopier) Copy(in map[string]string, out map[string]string) { 38 labels := make([]string, 0, len(in)) 39 40 for key, value := range in { 41 if mappedKey, exists := this.storedLabels[key]; exists { 42 out[mappedKey] = value 43 } 44 45 if _, exists := this.ignoredLabels[key]; !exists { 46 labels = append(labels, fmt.Sprintf("%s:%s", key, value)) 47 } 48 } 49 50 sort.Strings(labels) 51 out[core.LabelLabels.Key] = strings.Join(labels, this.labelSeparator) 52 } 53 54 // makeStoredLabels converts labels into a map for quicker retrieval. 55 // Incoming labels, if desired, may contain mappings in format "newName=oldName" 56 func makeStoredLabels(labels []string) map[string]string { 57 storedLabels := make(map[string]string) 58 for _, s := range labels { 59 split := strings.SplitN(s, "=", 2) 60 if len(split) == 1 { 61 storedLabels[split[0]] = split[0] 62 } else { 63 storedLabels[split[1]] = split[0] 64 } 65 } 66 return storedLabels 67 } 68 69 // makeIgnoredLabels converts label slice into a map for later use. 70 func makeIgnoredLabels(labels []string) map[string]string { 71 ignoredLabels := make(map[string]string) 72 for _, s := range labels { 73 ignoredLabels[s] = "" 74 } 75 return ignoredLabels 76 } 77 78 // NewLabelCopier creates a new instance of LabelCopier type 79 func NewLabelCopier(separator string, storedLabels, ignoredLabels []string) (*LabelCopier, error) { 80 return &LabelCopier{ 81 labelSeparator: separator, 82 storedLabels: makeStoredLabels(storedLabels), 83 ignoredLabels: makeIgnoredLabels(ignoredLabels), 84 }, nil 85 }