1515package metrics
1616
1717import (
18+ "errors"
1819 "fmt"
1920
2021 "github.com/prometheus/client_golang/prometheus"
6061 []string {
6162 "GVK" ,
6263 })
64+
65+ userMetrics = map [string ]prometheus.Collector {}
6366)
6467
6568func init () {
@@ -82,6 +85,165 @@ func RegisterBuildInfo(r prometheus.Registerer) {
8285 r .MustRegister (buildInfo )
8386}
8487
88+ type UserMetric struct {
89+ Name string `json:"name" yaml:"name"`
90+ Help string `json:"description" yaml:"description"`
91+ Counter * UserMetricCounter `json:"counter,omitempty" yaml:"counter,omitempty"`
92+ Gauge * UserMetricGauge `json:"gauge,omitempty" yaml:"gauge,omitempty"`
93+ Histogram * UserMetricHistogram `json:"histogram,omitempty" yaml:"histogram,omitempty"`
94+ Summary * UserMetricSummary `json:"summary,omitempty" yaml:"summary,omitempty"`
95+ }
96+
97+ type UserMetricCounter struct {
98+ Inc bool `json:"increment,omitempty" yaml:"increment,omitempty"`
99+ Add float64 `json:"add,omitempty" yaml:"add,omitempty"`
100+ }
101+
102+ type UserMetricGauge struct {
103+ Set float64 `json:"set,omitempty" yaml:"set,omitempty"`
104+ Inc bool `json:"increment,omitempty" yaml:"increment,omitempty"`
105+ Dec bool `json:"decrement,omitempty" yaml:"decrement,omitempty"`
106+ SetToCurrentTime bool `json:"set_to_current_time,omitempty" yaml:"set_to_current_time,omitempty"`
107+ Add float64 `json:"add,omitempty" yaml:"add,omitempty"`
108+ Sub float64 `json:"subtract,omitempty" yaml:"subtract,omitempty"`
109+ }
110+
111+ type UserMetricHistogram struct {
112+ Observe float64 `json:"observe,omitempty" yaml:"observe,omitempty"`
113+ }
114+
115+ type UserMetricSummary struct {
116+ Observe float64 `json:"observe,omitempty" yaml:"observe,omitempty"`
117+ }
118+
119+ func validateMetricSpec (metricSpec UserMetric ) error {
120+ var metricConfigs int
121+ if metricSpec .Counter != nil {
122+ metricConfigs ++
123+ }
124+ if metricSpec .Gauge != nil {
125+ metricConfigs ++
126+ }
127+ if metricSpec .Summary != nil {
128+ metricConfigs ++
129+ }
130+ if metricSpec .Histogram != nil {
131+ metricConfigs ++
132+ }
133+ if metricConfigs > 1 {
134+ return errors .New ("only one metric can be processed at a time" )
135+ } else if metricConfigs == 0 {
136+ return errors .New ("a request should contain at least one metric" )
137+ }
138+ return nil
139+ }
140+
141+ func handleCounter (metricSpec UserMetric , counter prometheus.Counter ) error {
142+ if metricSpec .Counter == nil {
143+ return fmt .Errorf ("cannot change metric type of %s, which is a counter" , metricSpec .Name )
144+ }
145+ if metricSpec .Counter .Inc {
146+ counter .Inc ()
147+ } else if metricSpec .Counter .Add != 0.0 {
148+ if metricSpec .Counter .Add < 0 {
149+ return errors .New ("counter metrics cannot decrease in value" )
150+ }
151+ counter .Add (metricSpec .Counter .Add )
152+ }
153+ return nil
154+ }
155+
156+ func handleGauge (metricSpec UserMetric , gauge prometheus.Gauge ) error {
157+ if metricSpec .Gauge == nil {
158+ return fmt .Errorf ("cannot change metric type of %s, which is a gauge" , metricSpec .Name )
159+ }
160+ if metricSpec .Gauge .Inc {
161+ gauge .Inc ()
162+ } else if metricSpec .Gauge .Dec {
163+ gauge .Dec ()
164+ } else if metricSpec .Gauge .Add != 0.0 {
165+ gauge .Add (metricSpec .Gauge .Add )
166+ } else if metricSpec .Gauge .Sub != 0.0 {
167+ gauge .Sub (metricSpec .Gauge .Sub )
168+ } else if metricSpec .Gauge .Set != 0.0 {
169+ gauge .Set (metricSpec .Gauge .Set )
170+ } else if metricSpec .Gauge .SetToCurrentTime {
171+ gauge .SetToCurrentTime ()
172+ }
173+ return nil
174+ }
175+
176+ func handleSummaryOrHistogram (metricSpec UserMetric , summary prometheus.Summary ) error {
177+ if metricSpec .Histogram == nil && metricSpec .Summary == nil {
178+ return fmt .Errorf ("cannot change metric type of %s, which is a histogram or summary" , metricSpec .Name )
179+ }
180+ if metricSpec .Histogram != nil {
181+ summary .Observe (metricSpec .Histogram .Observe )
182+ } else if metricSpec .Summary != nil {
183+ summary .Observe (metricSpec .Summary .Observe )
184+ }
185+ return nil
186+ }
187+
188+ func ensureMetric (r prometheus.Registerer , metricSpec UserMetric ) {
189+ if _ , ok := userMetrics [metricSpec .Name ]; ! ok {
190+ // This is the first time we've seen this metric
191+ logf .Log .WithName ("metrics" ).Info ("Registering" , "metric" , metricSpec .Name )
192+ if metricSpec .Counter != nil {
193+ userMetrics [metricSpec .Name ] = prometheus .NewCounter (prometheus.CounterOpts {
194+ Name : metricSpec .Name ,
195+ Help : metricSpec .Help ,
196+ })
197+ }
198+ if metricSpec .Gauge != nil {
199+ userMetrics [metricSpec .Name ] = prometheus .NewGauge (prometheus.GaugeOpts {
200+ Name : metricSpec .Name ,
201+ Help : metricSpec .Help ,
202+ })
203+ }
204+ if metricSpec .Histogram != nil {
205+ userMetrics [metricSpec .Name ] = prometheus .NewHistogram (prometheus.HistogramOpts {
206+ Name : metricSpec .Name ,
207+ Help : metricSpec .Help ,
208+ })
209+ }
210+ if metricSpec .Summary != nil {
211+ userMetrics [metricSpec .Name ] = prometheus .NewSummary (prometheus.SummaryOpts {
212+ Name : metricSpec .Name ,
213+ Help : metricSpec .Help ,
214+ })
215+ }
216+ if err := r .Register (userMetrics [metricSpec .Name ]); err != nil {
217+ logf .Log .WithName ("metrics" ).Info ("Unable to register %s metric with prometheus." , metricSpec .Name )
218+ }
219+ }
220+ }
221+
222+ func HandleUserMetric (r prometheus.Registerer , metricSpec UserMetric ) error {
223+ if err := validateMetricSpec (metricSpec ); err != nil {
224+ return err
225+ }
226+ ensureMetric (r , metricSpec )
227+ collector := userMetrics [metricSpec .Name ]
228+ switch v := collector .(type ) {
229+ // Gauge must be first, because a Counter is a Gauge, but a Gauge is not a Counter.
230+ case prometheus.Gauge :
231+ if err := handleGauge (metricSpec , v ); err != nil {
232+ return err
233+ }
234+ case prometheus.Counter :
235+ if err := handleCounter (metricSpec , v ); err != nil {
236+ return err
237+ }
238+ // Histogram and Summary interfaces are identical, so we accept either case.
239+ case prometheus.Histogram :
240+ if err := handleSummaryOrHistogram (metricSpec , v ); err != nil {
241+ return err
242+ }
243+ }
244+ return nil
245+ }
246+
85247func ReconcileSucceeded (gvk string ) {
86248 defer recoverMetricPanic ()
87249 reconcileResults .WithLabelValues (gvk , "succeeded" ).Inc ()
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