[OTEL-1738] Deprecate APMStatsConsumer (#320)

* [OTEL-1738] Deprecate APMStatsConsumer

* Add PR number

* lint

* Update changelog

.chloggen/deprecate-apm-stats-consumer.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component (e.g. pkg/quantile)
+component: pkg/otlp/metrics
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Deprecate the APMStatsConsumer interface and remove it from the Consumer interface.
+
+# The PR related to this change
+issues: [320]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: "The only breaking change is users can no longer do consumer.(*Consumer).ConsumeAPMStats(), instead they can do consumer.(*APMStatsConsumer).ConsumeAPMStats(). Everything else is backwards-compatible."

pkg/otlp/metrics/consumer.go

@@ -88,9 +88,9 @@ type SketchConsumer interface {
 type Consumer interface {
 	TimeSeriesConsumer
 	SketchConsumer
-	APMStatsConsumer
 }
 
+// Deprecated: use WithStatsOut instead
 // APMStatsConsumer implementations are able to consume APM Stats generated by
 // a Translator.
 type APMStatsConsumer interface {

pkg/otlp/metrics/metrics_translator_test.go

@@ -1922,11 +1922,6 @@ var _ SketchConsumer = (*mockFullConsumer)(nil)
 type mockFullConsumer struct {
 	mockTimeSeriesConsumer
 	sketches []sketch
-	apmstats []*pb.ClientStatsPayload
-}
-
-func (c *mockFullConsumer) ConsumeAPMStats(p *pb.ClientStatsPayload) {
-	c.apmstats = append(c.apmstats, p)
 }
 
 func (c *mockFullConsumer) ConsumeSketch(_ context.Context, dimensions *Dimensions, ts uint64, sk *quantile.Sketch) {

pkg/otlp/metrics/sketches_test.go

@@ -28,7 +28,6 @@ import (
 	"go.opentelemetry.io/collector/pdata/pmetric"
 	"go.uber.org/zap"
 
-	pb "github.com/DataDog/datadog-agent/pkg/proto/pbgo/trace"
 	"github.com/DataDog/opentelemetry-mapping-go/pkg/internal/sketchtest"
 	"github.com/DataDog/opentelemetry-mapping-go/pkg/quantile"
 )
@@ -40,12 +39,6 @@ type sketchConsumer struct {
 	sk *quantile.Sketch
 }
 
-func (c *sketchConsumer) ConsumeAPMStats(_ *pb.ClientStatsPayload) {
-	// not used for this consumer, but do warn the user if they
-	// try to use it
-	panic("(*sketchConsumer).ConsumeAPMStats not implemented")
-}
-
 // ConsumeSketch implements the translator.Consumer interface.
 func (c *sketchConsumer) ConsumeSketch(
 	_ context.Context,

pkg/otlp/metrics/testhelper_test.go

@@ -14,7 +14,6 @@ import (
 	"strings"
 	"testing"
 
-	pb "github.com/DataDog/datadog-agent/pkg/proto/pbgo/trace"
 	"github.com/DataDog/opentelemetry-mapping-go/pkg/otlp/attributes"
 	"github.com/DataDog/opentelemetry-mapping-go/pkg/quantile"
 	"github.com/DataDog/opentelemetry-mapping-go/pkg/quantile/summary"
@@ -132,12 +131,6 @@ type testConsumer struct {
 	testMetrics TestMetrics
 }
 
-func (t *testConsumer) ConsumeAPMStats(_ *pb.ClientStatsPayload) {
-	// not used for this consumer, but do warn the user if they
-	// try to use it
-	panic("(*testConsumer).ConsumeAPMStats not implemented")
-}
-
 func (t *testConsumer) ConsumeTimeSeries(
 	_ context.Context,
 	dimensions *Dimensions,