metrics: Delete ToProm() method from granular metrics

Instead, implement prometheus.Collector interface for granular metrics structs, i.e. Describe and Collect methods that access the underlying Prometheus metric. This allows us to register and test granular metrics directly, without unnecessarily exposing internal implementation. Signed-off-by: Anna Kapuscinska <anna@isovalent.com>
cilium · Apr 17, 2024 · 1a50ec4 · 1a50ec4
1 parent fbe7e3c
commit 1a50ec4
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Showing 4 changed files with 23 additions and 11 deletions.
diff --git a/pkg/metrics/eventmetrics/eventmetrics.go b/pkg/metrics/eventmetrics/eventmetrics.go
@@ -68,8 +68,8 @@ func InitHealthMetrics(registry *prometheus.Registry) {
 }
 
 func InitEventsMetrics(registry *prometheus.Registry) {
-	registry.MustRegister(EventsProcessed.ToProm())
-	registry.MustRegister(policyStats.ToProm())
+	registry.MustRegister(EventsProcessed)
+	registry.MustRegister(policyStats)
 }
 
 func InitEventsMetricsForDocs(registry *prometheus.Registry) {

diff --git a/pkg/metrics/eventmetrics/eventmetrics_test.go b/pkg/metrics/eventmetrics/eventmetrics_test.go
@@ -15,7 +15,7 @@ import (
 )
 
 func TestHandleProcessedEvent(t *testing.T) {
-	assert.NoError(t, testutil.CollectAndCompare(EventsProcessed.ToProm(), strings.NewReader("")))
+	assert.NoError(t, testutil.CollectAndCompare(EventsProcessed, strings.NewReader("")))
 	handleProcessedEvent(nil, nil)
 	// empty process
 	handleProcessedEvent(nil, &tetragon.GetEventsResponse{Event: &tetragon.GetEventsResponse_ProcessKprobe{ProcessKprobe: &tetragon.ProcessKprobe{}}})
@@ -79,7 +79,7 @@ tetragon_events_total{binary="binary_c",namespace="namespace_c",pod="pod_c",type
 tetragon_events_total{binary="binary_e",namespace="",pod="",type="PROCESS_EXIT",workload=""} 1
 tetragon_events_total{binary="binary_e",namespace="namespace_e",pod="pod_e",type="PROCESS_EXIT",workload="workload_e"} 1
 `)
-	assert.NoError(t, testutil.CollectAndCompare(EventsProcessed.ToProm(), expected))
+	assert.NoError(t, testutil.CollectAndCompare(EventsProcessed, expected))
 }
 
 func TestHandleOriginalEvent(t *testing.T) {

diff --git a/pkg/metrics/granularmetric.go b/pkg/metrics/granularmetric.go
@@ -48,8 +48,12 @@ func MustNewGranularCounter[L FilteredLabels](opts prometheus.CounterOpts, extra
 	return result
 }
 
-func (m *GranularCounter[L]) ToProm() *prometheus.CounterVec {
-	return m.metric
+func (m *GranularCounter[L]) Describe(ch chan<- *prometheus.Desc) {
+	m.metric.Describe(ch)
+}
+
+func (m *GranularCounter[L]) Collect(ch chan<- prometheus.Metric) {
+	m.metric.Collect(ch)
 }
 
 func (m *GranularCounter[L]) WithLabelValues(commonLvs *L, extraLvs ...string) prometheus.Counter {
@@ -86,8 +90,12 @@ func MustNewGranularGauge[L FilteredLabels](opts prometheus.GaugeOpts, extraLabe
 	return result
 }
 
-func (m *GranularGauge[L]) ToProm() *prometheus.GaugeVec {
-	return m.metric
+func (m *GranularGauge[L]) Describe(ch chan<- *prometheus.Desc) {
+	m.metric.Describe(ch)
+}
+
+func (m *GranularGauge[L]) Collect(ch chan<- prometheus.Metric) {
+	m.metric.Collect(ch)
 }
 
 func (m *GranularGauge[L]) WithLabelValues(commonLvs *L, extraLvs ...string) prometheus.Gauge {
@@ -124,8 +132,12 @@ func MustNewGranularHistogram[L FilteredLabels](opts prometheus.HistogramOpts, e
 	return result
 }
 
-func (m *GranularHistogram[L]) ToProm() *prometheus.HistogramVec {
-	return m.metric
+func (m *GranularHistogram[L]) Describe(ch chan<- *prometheus.Desc) {
+	m.metric.Describe(ch)
+}
+
+func (m *GranularHistogram[L]) Collect(ch chan<- prometheus.Metric) {
+	m.metric.Collect(ch)
 }
 
 func (m *GranularHistogram[L]) WithLabelValues(commonLvs *L, extraLvs ...string) prometheus.Observer {

diff --git a/pkg/metrics/syscallmetrics/syscallmetrics.go b/pkg/metrics/syscallmetrics/syscallmetrics.go
@@ -21,7 +21,7 @@ var (
 )
 
 func InitMetrics(registry *prometheus.Registry) {
-	registry.MustRegister(syscallStats.ToProm())
+	registry.MustRegister(syscallStats)
 
 	// NOTES:
 	// * Delete syscalls_total? It seems to duplicate policy_events_total.