Create generic statsReporter in metrics package

pkg/metrics/stats_reporter.go

@@ -0,0 +1,60 @@
+/*
+Copyright 2020 The Knative 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 metrics
+
+import (
+	"context"
+	"log"
+
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+	"knative.dev/pkg/metrics"
+)
+
+type MetricArgs interface {
+	GenerateTag(tags ...tag.Mutator) (context.Context, error)
+}
+
+func init() {
+	Register([]stats.Measure{}, nil)
+}
+
+// StatsReporter defines the interface for sending filter metrics.
+type StatsReporter interface {
+}
+
+func Register(customMetrics []stats.Measure, customViews []*view.View, customTagKeys ...tag.Key) {
+	allTagKeys := append(customTagKeys)
+	allViews := append(customViews)
+
+	// Add custom views for custom metrics
+	for _, metric := range customMetrics {
+		allViews = append(allViews, &view.View{
+			Description: metric.Description(),
+			Name:        metric.Name(),
+			Measure:     metric,
+			Aggregation: view.LastValue(),
+			TagKeys:     allTagKeys,
+		})
+	}
+
+	// Append custom views
+	if err := metrics.RegisterResourceView(allViews...); err != nil {
+		log.Printf("Failed to register opencensus views: %v", err)
+	}
+}

pkg/metrics/stats_repoter_test.go

@@ -0,0 +1,146 @@
+/*
+Copyright 2020 The Knative 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 metrics_test
+
+import (
+	"context"
+	"testing"
+
+	"go.opencensus.io/resource"
+	"go.opencensus.io/stats"
+	"go.opencensus.io/stats/view"
+	"go.opencensus.io/tag"
+	eventingmetrics "knative.dev/eventing/pkg/metrics"
+	"knative.dev/pkg/metrics/metricskey"
+	"knative.dev/pkg/metrics/metricstest"
+	_ "knative.dev/pkg/metrics/testing"
+)
+
+type testMetricArgs struct {
+	ns        string
+	trigger   string
+	broker    string
+	testParam string
+}
+
+func (args *testMetricArgs) GenerateTag(tags ...tag.Mutator) (context.Context, error) {
+	ctx := metricskey.WithResource(context.Background(), resource.Resource{
+		Type: eventingmetrics.ResourceTypeKnativeTrigger,
+		Labels: map[string]string{
+			eventingmetrics.LabelNamespaceName: args.ns,
+			eventingmetrics.LabelBrokerName:    args.broker,
+			eventingmetrics.LabelTriggerName:   args.trigger,
+		},
+	})
+	ctx, err := tag.New(
+		ctx,
+		append(tags,
+			tag.Insert(customTagKey, args.testParam),
+		)...)
+	return ctx, err
+}
+
+var (
+	customMetricM = stats.Int64(
+		"custom_metric",
+		"A custom metric for testing",
+		stats.UnitDimensionless,
+	)
+
+	customTagKey = tag.MustNewKey("custom_tag")
+)
+
+// StatsReporter interface definition
+type StatsReporter interface {
+	eventingmetrics.StatsReporter
+	ReportCustomMetric(args eventingmetrics.MetricArgs, value int64) error
+}
+
+// reporter struct definition
+type reporter struct {
+	container  string
+	uniqueName string
+}
+
+// ReportCustomMetric records a custom metric value.
+func (r *reporter) ReportCustomMetric(args eventingmetrics.MetricArgs, value int64) error {
+	// Create base tags
+	baseTags := []tag.Mutator{
+		tag.Insert(tag.MustNewKey("unique_name"), r.uniqueName),
+		tag.Insert(tag.MustNewKey("container_name"), r.container),
+	}
+
+	// Generate context with all tags, including any custom ones from args.GenerateTag
+	ctx, err := args.GenerateTag(baseTags...)
+	if err != nil {
+		return err
+	}
+
+	// Record the custom metric
+	stats.Record(ctx, customMetricM.M(value))
+	return nil
+}
+
+func TestRegisterCustomMetrics(t *testing.T) {
+	setup()
+
+	args := &testMetricArgs{
+		ns:        "test-namespace",
+		trigger:   "test-trigger",
+		broker:    "test-broker",
+		testParam: "test-param",
+	}
+	r := &reporter{
+		container:  "testcontainer",
+		uniqueName: "testpod",
+	}
+
+	customMetrics := []stats.Measure{customMetricM}
+
+	customTagKeys := []tag.Key{customTagKey}
+
+	// No need for customViews, as the custom metric will be used to create the view
+	eventingmetrics.Register(customMetrics, nil, customTagKeys...)
+
+	// Verify that the custom view is registered
+	if v := view.Find("custom_metric"); v == nil {
+		t.Error("Custom view was not registered")
+	}
+
+	// Record a value for the custom metric
+	expectSuccess(t, func() error {
+		return r.ReportCustomMetric(args, 100)
+	})
+
+	// Check if the value was recorded correctly
+	metricstest.CheckLastValueData(t, "custom_metric", map[string]string{"custom_tag": "test-param"}, 100)
+}
+
+func expectSuccess(t *testing.T, f func() error) {
+	t.Helper()
+	if err := f(); err != nil {
+		t.Errorf("Reporter expected success but got error: %v", err)
+	}
+}
+
+func setup() {
+	resetMetrics()
+}
+
+func resetMetrics() {
+	metricstest.Unregister("custom_metric")
+	eventingmetrics.Register([]stats.Measure{}, nil)
+}