Add otlpmetricgrpc.Expoter and otlpmetrichttp.Exporter (#4272)

* Add otlpmetricgrpc.Expoter and otlpmetrichttp.Exporter

* Update changelog

CHANGELOG.md

@@ -12,6 +12,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Add `ManualReader` struct in `go.opentelemetry.io/otel/sdk/metric`. (#4244)
 - Add `PeriodicReader` struct in `go.opentelemetry.io/otel/sdk/metric`. (#4244)
+- Add `Exporter` struct in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4272)
+- Add `Exporter` struct in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4272)
 
 ### Changed
 
@@ -21,6 +23,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - `NewManualReader` in `go.opentelemetry.io/otel/sdk/metric` returns `*ManualReader` instead of `Reader`. (#4244)
 - `NewPeriodicReader` in `go.opentelemetry.io/otel/sdk/metric` returns `*PeriodicReader` instead of `Reader`. (#4244)
 - Count the Collect time in the PeriodicReader timeout. (#4221)
+- `New` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` returns `*Exporter` instead of `"go.opentelemetry.io/otel/sdk/metric".Exporter`. (#4272)
+- `New` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` returns `*Exporter` instead of `"go.opentelemetry.io/otel/sdk/metric".Exporter`. (#4272)
 
 ### Fixed
 

exporters/otlp/otlpmetric/internal/exporter.go

@@ -26,8 +26,8 @@ import (
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
-// exporter exports metrics data as OTLP.
+// Exporter exports metrics data as OTLP.
-type exporter struct {
+type Exporter struct {
 	// Ensure synchronous access to the client across all functionality.
 	clientMu sync.Mutex
 	client   Client
@@ -36,21 +36,21 @@ type exporter struct {
 }
 
 // Temporality returns the Temporality to use for an instrument kind.
-func (e *exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
+func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
 	return e.client.Temporality(k)
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (e *exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
 	return e.client.Aggregation(k)
 }
 
 // Export transforms and transmits metric data to an OTLP receiver.
-func (e *exporter) Export(ctx context.Context, rm *metricdata.ResourceMetrics) error {
+func (e *Exporter) Export(ctx context.Context, rm *metricdata.ResourceMetrics) error {
 	otlpRm, err := transform.ResourceMetrics(rm)
 	// Best effort upload of transformable metrics.
 	e.clientMu.Lock()
@@ -67,7 +67,7 @@ func (e *exporter) Export(ctx context.Context, rm *metricdata.ResourceMetrics) e
 }
 
 // ForceFlush flushes any metric data held by an exporter.
-func (e *exporter) ForceFlush(ctx context.Context) error {
+func (e *Exporter) ForceFlush(ctx context.Context) error {
 	// The Exporter does not hold data, forward the command to the client.
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
@@ -78,7 +78,7 @@ var errShutdown = fmt.Errorf("exporter is shutdown")
 
 // Shutdown flushes all metric data held by an exporter and releases any held
 // computational resources.
-func (e *exporter) Shutdown(ctx context.Context) error {
+func (e *Exporter) Shutdown(ctx context.Context) error {
 	err := errShutdown
 	e.shutdownOnce.Do(func() {
 		e.clientMu.Lock()
@@ -96,8 +96,8 @@ func (e *exporter) Shutdown(ctx context.Context) error {
 // New return an Exporter that uses client to transmits the OTLP data it
 // produces. The client is assumed to be fully started and able to communicate
 // with its OTLP receiving endpoint.
-func New(client Client) metric.Exporter {
+func New(client Client) *Exporter {
-	return &exporter{client: client}
+	return &Exporter{client: client}
 }
 
 type shutdownClient struct {

exporters/otlp/otlpmetric/otlpmetricgrpc/client.go

@@ -36,22 +36,6 @@ import (
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
-// New returns an OpenTelemetry metric Exporter. The Exporter can be used with
-// a PeriodicReader to export OpenTelemetry metric data to an OTLP receiving
-// endpoint using gRPC.
-//
-// If an already established gRPC ClientConn is not passed in options using
-// WithGRPCConn, a connection to the OTLP endpoint will be established based
-// on options. If a connection cannot be establishes in the lifetime of ctx,
-// an error will be returned.
-func New(ctx context.Context, options ...Option) (metric.Exporter, error) {
-	c, err := newClient(ctx, options...)
-	if err != nil {
-		return nil, err
-	}
-	return ominternal.New(c), nil
-}
-
 type client struct {
 	metadata      metadata.MD
 	exportTimeout time.Duration

exporters/otlp/otlpmetric/otlpmetricgrpc/exporter.go

@@ -0,0 +1,85 @@
+// Copyright The OpenTelemetry 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 otlpmetricgrpc // import "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+
+import (
+	"context"
+
+	ominternal "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+)
+
+// Exporter is a OpenTelemetry metric Exporter using gRPC.
+type Exporter struct {
+	wrapped *ominternal.Exporter
+}
+
+// Temporality returns the Temporality to use for an instrument kind.
+func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
+	return e.wrapped.Temporality(k)
+}
+
+// Aggregation returns the Aggregation to use for an instrument kind.
+func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+	return e.wrapped.Aggregation(k)
+}
+
+// Export transforms and transmits metric data to an OTLP receiver.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+func (e *Exporter) Export(ctx context.Context, rm *metricdata.ResourceMetrics) error {
+	return e.wrapped.Export(ctx, rm)
+}
+
+// ForceFlush flushes any metric data held by an exporter.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+//
+// This method is safe to call concurrently.
+func (e *Exporter) ForceFlush(ctx context.Context) error {
+	return e.wrapped.ForceFlush(ctx)
+}
+
+// Shutdown flushes all metric data held by an exporter and releases any held
+// computational resources.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+//
+// This method is safe to call concurrently.
+func (e *Exporter) Shutdown(ctx context.Context) error {
+	return e.wrapped.Shutdown(ctx)
+}
+
+// New returns an OpenTelemetry metric Exporter. The Exporter can be used with
+// a PeriodicReader to export OpenTelemetry metric data to an OTLP receiving
+// endpoint using gRPC.
+//
+// If an already established gRPC ClientConn is not passed in options using
+// WithGRPCConn, a connection to the OTLP endpoint will be established based
+// on options. If a connection cannot be establishes in the lifetime of ctx,
+// an error will be returned.
+func New(ctx context.Context, options ...Option) (*Exporter, error) {
+	c, err := newClient(ctx, options...)
+	if err != nil {
+		return nil, err
+	}
+	exp := ominternal.New(c)
+	return &Exporter{exp}, nil
+}

exporters/otlp/otlpmetric/otlpmetrichttp/client.go

@@ -41,17 +41,6 @@ import (
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
-// New returns an OpenTelemetry metric Exporter. The Exporter can be used with
-// a PeriodicReader to export OpenTelemetry metric data to an OTLP receiving
-// endpoint using protobufs over HTTP.
-func New(_ context.Context, opts ...Option) (metric.Exporter, error) {
-	c, err := newClient(opts...)
-	if err != nil {
-		return nil, err
-	}
-	return ominternal.New(c), nil
-}
-
 type client struct {
 	// req is cloned for every upload the client makes.
 	req         *http.Request

exporters/otlp/otlpmetric/otlpmetrichttp/exporter.go

@@ -0,0 +1,80 @@
+// Copyright The OpenTelemetry 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 otlpmetrichttp // import "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
+
+import (
+	"context"
+
+	ominternal "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/metric/aggregation"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+)
+
+// Exporter is a OpenTelemetry metric Exporter using protobufs over HTTP.
+type Exporter struct {
+	wrapped *ominternal.Exporter
+}
+
+// Temporality returns the Temporality to use for an instrument kind.
+func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
+	return e.wrapped.Temporality(k)
+}
+
+// Aggregation returns the Aggregation to use for an instrument kind.
+func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+	return e.wrapped.Aggregation(k)
+}
+
+// Export transforms and transmits metric data to an OTLP receiver.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+func (e *Exporter) Export(ctx context.Context, rm *metricdata.ResourceMetrics) error {
+	return e.wrapped.Export(ctx, rm)
+}
+
+// ForceFlush flushes any metric data held by an exporter.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+//
+// This method is safe to call concurrently.
+func (e *Exporter) ForceFlush(ctx context.Context) error {
+	return e.wrapped.ForceFlush(ctx)
+}
+
+// Shutdown flushes all metric data held by an exporter and releases any held
+// computational resources.
+//
+// This method returns an error if called after Shutdown.
+// This method returns an error if the method is canceled by the passed context.
+//
+// This method is safe to call concurrently.
+func (e *Exporter) Shutdown(ctx context.Context) error {
+	return e.wrapped.Shutdown(ctx)
+}
+
+// New returns an OpenTelemetry metric Exporter. The Exporter can be used with
+// a PeriodicReader to export OpenTelemetry metric data to an OTLP receiving
+// endpoint using protobufs over HTTP.
+func New(_ context.Context, opts ...Option) (*Exporter, error) {
+	c, err := newClient(opts...)
+	if err != nil {
+		return nil, err
+	}
+	exp := ominternal.New(c)
+	return &Exporter{exp}, nil
+}