OTLP metric exporter - resource attributes not exported

[alanwest]

Description

Resource attributes are not exported using the OTLP metric exporter.

Environment

• opentelemetry-go version: v0.32.0

Steps To Reproduce

1. Configure OTLP endpoint
   • OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317
2. Run the collector locally with the following config

receivers:
  otlp:
    protocols:
      grpc:

exporters:
  logging:
    loglevel: debug

service:
  pipelines:
    metrics:
      receivers: [otlp]
      exporters: [logging]

3. Run the following code

package main

import (
	"context"
	"log"
	"time"

	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
	"go.opentelemetry.io/otel/metric/global"
	"go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/resource"

	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
)

func main() {
	ctx := context.Background()

	exporter, err := otlpmetricgrpc.New(ctx)
	if err != nil {
		log.Fatalf("%s: %v", "failed to create metric exporter", err)
	}

	reader := metric.NewPeriodicReader(
		exporter,
		metric.WithInterval(2*time.Second),
	)

	res := resource.NewWithAttributes(
		semconv.SchemaURL,

                 // This attribute is not exported
		semconv.ServiceNameKey.String("my-service"),
	)

	meterProvider := metric.NewMeterProvider(
		metric.WithResource(res),
		metric.WithReader(reader),
	)
	global.SetMeterProvider(meterProvider)

	meter := global.Meter("my-meter")

	counter, err := meter.SyncFloat64().Counter("my-counter")
	if err != nil {
		log.Panicf("failed to initialize instrument: %v", err)
	}

	counter.Add(ctx, 12.0)
	time.Sleep(5 * time.Second)
	counter.Add(ctx, 22.0)
	time.Sleep(5 * time.Second)
	counter.Add(ctx, 13.0)

	defer func() {
		err := meterProvider.Shutdown(context.Background())
		if err != nil {
			log.Fatalln(err)
		}
	}()
}

4. Output from collector's logging exporter

2022-09-20T14:31:28.721-0700	info	MetricsExporter	{"kind": "exporter", "data_type": "metrics", "name": "logging", "#metrics": 1}
2022-09-20T14:31:28.722-0700	info	ResourceMetrics #0
Resource SchemaURL: 
ScopeMetrics #0
ScopeMetrics SchemaURL: 
InstrumentationScope my-meter 
Metric #0
Descriptor:
     -> Name: my-counter
     -> Description: 
     -> Unit: 
     -> DataType: Sum
     -> IsMonotonic: true
     -> AggregationTemporality: AGGREGATION_TEMPORALITY_CUMULATIVE
NumberDataPoints #0
StartTimestamp: 2022-09-20 21:31:26.683813 +0000 UTC
Timestamp: 2022-09-20 21:31:28.685045 +0000 UTC
Value: 12.000000
	{"kind": "exporter", "data_type": "metrics", "name": "logging"}

Expected behavior

Resource should include the attribute service.name=my-service

[MrAlias]

@alanwest what version of the collector was used in the example?

[alanwest]

I built and ran the collector locally from main.

[MrAlias]

It looks like newPipelineRegistries initializes pipelines without a resource:

opentelemetry-go/sdk/metric/pipeline.go

Line 171 in 038248b

pipe := &pipeline{}

cc @MadVikingGod

[MrAlias]

This exists for the stdoutmetric exporter as well:

package main

import (
	"context"
	"log"
	"time"

	"go.opentelemetry.io/otel/exporters/stdout/stdoutmetric"
	"go.opentelemetry.io/otel/sdk/metric"
	"go.opentelemetry.io/otel/sdk/resource"

	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
)

func main() {
	ctx := context.Background()

	exporter, err := stdoutmetric.New()
	if err != nil {
		log.Fatalf("failed to create metric exporter: %v", err)
	}

	reader := metric.NewPeriodicReader(
		exporter,
		metric.WithInterval(time.Second),
	)

	res := resource.NewWithAttributes(
		semconv.SchemaURL,
		// This attribute is not exported
		semconv.ServiceNameKey.String("my-service"),
	)
	log.Println("resource:", res)

	meterProvider := metric.NewMeterProvider(
		metric.WithResource(res),
		metric.WithReader(reader),
	)
	meter := meterProvider.Meter("my-meter")

	counter, err := meter.SyncFloat64().Counter("my-counter")
	if err != nil {
		log.Fatalf("failed to initialize instrument: %v", err)
	}

	counter.Add(ctx, 12.0)
	time.Sleep(2 * time.Second)

	err = meterProvider.Shutdown(ctx)
	if err != nil {
		log.Fatalln("failed to shutdown", err)
	}
}

go 1.19

require (
	go.opentelemetry.io/otel v1.10.0
	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v0.32.0
	go.opentelemetry.io/otel/exporters/stdout/stdoutmetric v0.32.0
	go.opentelemetry.io/otel/sdk v1.10.0
	go.opentelemetry.io/otel/sdk/metric v0.32.0
)

require (
	github.com/cenkalti/backoff/v4 v4.1.3 // indirect
	github.com/go-logr/logr v1.2.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/golang/protobuf v1.5.2 // indirect
	github.com/grpc-ecosystem/grpc-gateway/v2 v2.7.0 // indirect
	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.10.0 // indirect
	go.opentelemetry.io/otel/exporters/otlp/otlpmetric v0.32.0 // indirect
	go.opentelemetry.io/otel/metric v0.32.0 // indirect
	go.opentelemetry.io/otel/trace v1.10.0 // indirect
	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4 // indirect
	golang.org/x/sys v0.0.0-20210510120138-977fb7262007 // indirect
	golang.org/x/text v0.3.5 // indirect
	google.golang.org/genproto v0.0.0-20211118181313-81c1377c94b1 // indirect
	google.golang.org/grpc v1.46.2 // indirect
	google.golang.org/protobuf v1.28.0 // indirect
)

[MrAlias]

Validated with the above examples #3218 should resolve this.

[fracasula]

I'm still experiencing this on the latest (main branch) when I set custom attributes like:

otelRes := resource.NewWithAttributes(
	semconv.SchemaURL,
	semconv.ServiceName("test server"),
	semconv.ServiceVersion("v0.1.0"),
	attribute.String("foo", "bar"), // we expect this to be propagated
)

I'm not seeing the "foo=bar" attribute propagated in the metric. I hacked my way through this to solve it but it doesn't feel right, please have a look at this test where I'm replicating the issue.

[fracasula]

The resource seems to be propagated as is, I checked the gRPC client as well so the fact that I don't see foo=bar on the other side must depend on the otel collector not processing extra attributes that are attached to the resource. Maybe it's processing the semconv ones only? My hack works around the problem since I'm adding those attributes manually into the data points. Can I get your 2 cents on this @MrAlias ?

[MrAlias]

@fracasula please open a new bug. The bug described by this issue is still fixed according to the validation it contains.

[fracasula]

@fracasula please open a new bug. The bug described by this issue is still fixed according to the validation it contains.

Done here @MrAlias