blob: 41051a01a36d49c5b85be61dcdaadb6030f6bf98 [file] [log] [blame]
Matthias Andreas Benkard832a54e2019-01-29 09:27:38 +01001// Copyright 2013 The Prometheus Authors
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14package model
15
16import (
17 "encoding/json"
18 "fmt"
19 "regexp"
20 "strings"
21 "unicode/utf8"
22)
23
24const (
25 // AlertNameLabel is the name of the label containing the an alert's name.
26 AlertNameLabel = "alertname"
27
28 // ExportedLabelPrefix is the prefix to prepend to the label names present in
29 // exported metrics if a label of the same name is added by the server.
30 ExportedLabelPrefix = "exported_"
31
32 // MetricNameLabel is the label name indicating the metric name of a
33 // timeseries.
34 MetricNameLabel = "__name__"
35
36 // SchemeLabel is the name of the label that holds the scheme on which to
37 // scrape a target.
38 SchemeLabel = "__scheme__"
39
40 // AddressLabel is the name of the label that holds the address of
41 // a scrape target.
42 AddressLabel = "__address__"
43
44 // MetricsPathLabel is the name of the label that holds the path on which to
45 // scrape a target.
46 MetricsPathLabel = "__metrics_path__"
47
48 // ReservedLabelPrefix is a prefix which is not legal in user-supplied
49 // label names.
50 ReservedLabelPrefix = "__"
51
52 // MetaLabelPrefix is a prefix for labels that provide meta information.
53 // Labels with this prefix are used for intermediate label processing and
54 // will not be attached to time series.
55 MetaLabelPrefix = "__meta_"
56
57 // TmpLabelPrefix is a prefix for temporary labels as part of relabelling.
58 // Labels with this prefix are used for intermediate label processing and
59 // will not be attached to time series. This is reserved for use in
60 // Prometheus configuration files by users.
61 TmpLabelPrefix = "__tmp_"
62
63 // ParamLabelPrefix is a prefix for labels that provide URL parameters
64 // used to scrape a target.
65 ParamLabelPrefix = "__param_"
66
67 // JobLabel is the label name indicating the job from which a timeseries
68 // was scraped.
69 JobLabel = "job"
70
71 // InstanceLabel is the label name used for the instance label.
72 InstanceLabel = "instance"
73
74 // BucketLabel is used for the label that defines the upper bound of a
75 // bucket of a histogram ("le" -> "less or equal").
76 BucketLabel = "le"
77
78 // QuantileLabel is used for the label that defines the quantile in a
79 // summary.
80 QuantileLabel = "quantile"
81)
82
83// LabelNameRE is a regular expression matching valid label names. Note that the
84// IsValid method of LabelName performs the same check but faster than a match
85// with this regular expression.
86var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
87
88// A LabelName is a key for a LabelSet or Metric. It has a value associated
89// therewith.
90type LabelName string
91
92// IsValid is true iff the label name matches the pattern of LabelNameRE. This
93// method, however, does not use LabelNameRE for the check but a much faster
94// hardcoded implementation.
95func (ln LabelName) IsValid() bool {
96 if len(ln) == 0 {
97 return false
98 }
99 for i, b := range ln {
100 if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) {
101 return false
102 }
103 }
104 return true
105}
106
107// UnmarshalYAML implements the yaml.Unmarshaler interface.
108func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
109 var s string
110 if err := unmarshal(&s); err != nil {
111 return err
112 }
113 if !LabelName(s).IsValid() {
114 return fmt.Errorf("%q is not a valid label name", s)
115 }
116 *ln = LabelName(s)
117 return nil
118}
119
120// UnmarshalJSON implements the json.Unmarshaler interface.
121func (ln *LabelName) UnmarshalJSON(b []byte) error {
122 var s string
123 if err := json.Unmarshal(b, &s); err != nil {
124 return err
125 }
126 if !LabelName(s).IsValid() {
127 return fmt.Errorf("%q is not a valid label name", s)
128 }
129 *ln = LabelName(s)
130 return nil
131}
132
133// LabelNames is a sortable LabelName slice. In implements sort.Interface.
134type LabelNames []LabelName
135
136func (l LabelNames) Len() int {
137 return len(l)
138}
139
140func (l LabelNames) Less(i, j int) bool {
141 return l[i] < l[j]
142}
143
144func (l LabelNames) Swap(i, j int) {
145 l[i], l[j] = l[j], l[i]
146}
147
148func (l LabelNames) String() string {
149 labelStrings := make([]string, 0, len(l))
150 for _, label := range l {
151 labelStrings = append(labelStrings, string(label))
152 }
153 return strings.Join(labelStrings, ", ")
154}
155
156// A LabelValue is an associated value for a LabelName.
157type LabelValue string
158
159// IsValid returns true iff the string is a valid UTF8.
160func (lv LabelValue) IsValid() bool {
161 return utf8.ValidString(string(lv))
162}
163
164// LabelValues is a sortable LabelValue slice. It implements sort.Interface.
165type LabelValues []LabelValue
166
167func (l LabelValues) Len() int {
168 return len(l)
169}
170
171func (l LabelValues) Less(i, j int) bool {
172 return string(l[i]) < string(l[j])
173}
174
175func (l LabelValues) Swap(i, j int) {
176 l[i], l[j] = l[j], l[i]
177}
178
179// LabelPair pairs a name with a value.
180type LabelPair struct {
181 Name LabelName
182 Value LabelValue
183}
184
185// LabelPairs is a sortable slice of LabelPair pointers. It implements
186// sort.Interface.
187type LabelPairs []*LabelPair
188
189func (l LabelPairs) Len() int {
190 return len(l)
191}
192
193func (l LabelPairs) Less(i, j int) bool {
194 switch {
195 case l[i].Name > l[j].Name:
196 return false
197 case l[i].Name < l[j].Name:
198 return true
199 case l[i].Value > l[j].Value:
200 return false
201 case l[i].Value < l[j].Value:
202 return true
203 default:
204 return false
205 }
206}
207
208func (l LabelPairs) Swap(i, j int) {
209 l[i], l[j] = l[j], l[i]
210}