fix(collector) respect log level as configured in collector config

collector/go.mod

@@ -33,7 +33,10 @@ require (
 	go.opentelemetry.io/collector/confmap/provider/httpprovider v1.56.0
 	go.opentelemetry.io/collector/confmap/provider/httpsprovider v1.56.0
 	go.opentelemetry.io/collector/confmap/provider/yamlprovider v1.56.0
+	go.opentelemetry.io/collector/exporter/exportertest v0.150.0
 	go.opentelemetry.io/collector/otelcol v0.150.0
+	go.opentelemetry.io/collector/receiver/receivertest v0.150.0
+	go.opentelemetry.io/collector/service v0.150.0
 	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.27.1
 )
@@ -202,7 +205,6 @@ require (
 	go.opentelemetry.io/collector/exporter/debugexporter v0.150.0 // indirect
 	go.opentelemetry.io/collector/exporter/exporterhelper v0.150.0 // indirect
 	go.opentelemetry.io/collector/exporter/exporterhelper/xexporterhelper v0.150.0 // indirect
-	go.opentelemetry.io/collector/exporter/exportertest v0.150.0 // indirect
 	go.opentelemetry.io/collector/exporter/otlpexporter v0.150.0 // indirect
 	go.opentelemetry.io/collector/exporter/otlphttpexporter v0.150.0 // indirect
 	go.opentelemetry.io/collector/exporter/xexporter v0.150.0 // indirect
@@ -234,10 +236,8 @@ require (
 	go.opentelemetry.io/collector/receiver v1.56.0 // indirect
 	go.opentelemetry.io/collector/receiver/otlpreceiver v0.150.0 // indirect
 	go.opentelemetry.io/collector/receiver/receiverhelper v0.150.0 // indirect
-	go.opentelemetry.io/collector/receiver/receivertest v0.150.0 // indirect
 	go.opentelemetry.io/collector/receiver/xreceiver v0.150.0 // indirect
 	go.opentelemetry.io/collector/semconv v0.128.0 // indirect
-	go.opentelemetry.io/collector/service v0.150.0 // indirect
 	go.opentelemetry.io/collector/service/hostcapabilities v0.150.0 // indirect
 	go.opentelemetry.io/contrib/bridges/otelzap v0.18.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.68.0 // indirect

collector/internal/collector/collector.go

@@ -103,8 +103,18 @@ func (c *Collector) Start(ctx context.Context) error {
 		Factories: func() (otelcol.Factories, error) {
 			return c.factories, nil
 		},
-		LoggingOptions: []zap.Option{zap.WrapCore(func(_ zapcore.Core) zapcore.Core {
-			return c.logger.Core()
+		// TODO: fully decouple extension and collector log levels so that
+		// OPENTELEMETRY_EXTENSION_LOG_LEVEL only affects extension logs.
+		LoggingOptions: []zap.Option{zap.WrapCore(func(collectorCore zapcore.Core) zapcore.Core {
+			extensionCore := c.logger.Core()
+			if zapcore.LevelOf(collectorCore) == zapcore.InfoLevel {
+				return extensionCore
+			}
+			increased, err := zapcore.NewIncreaseLevelCore(extensionCore, collectorCore)
+			if err != nil {
+				return extensionCore
+			}
+			return increased
 		})},
 	}
 	var err error

collector/internal/collector/collector_test.go

@@ -0,0 +1,63 @@
+// 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 collector
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/exporter/exportertest"
+	"go.opentelemetry.io/collector/otelcol"
+	"go.opentelemetry.io/collector/receiver/receivertest"
+	"go.opentelemetry.io/collector/service/telemetry/otelconftelemetry"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"go.uber.org/zap/zaptest/observer"
+)
+
+func TestCollectorConfigLogLevelIsOverridden(t *testing.T) {
+	t.Setenv("OPENTELEMETRY_COLLECTOR_CONFIG_URI", "file:testdata/config-error-level.yaml")
+
+	receivers, err := otelcol.MakeFactoryMap(receivertest.NewNopFactory())
+	require.NoError(t, err)
+	exporters, err := otelcol.MakeFactoryMap(exportertest.NewNopFactory())
+	require.NoError(t, err)
+
+	factories := otelcol.Factories{
+		Receivers: receivers,
+		Exporters: exporters,
+		Telemetry: otelconftelemetry.NewFactory(),
+	}
+
+	// Use a nop logger so extension logs don't end up in our observer
+	collector := NewCollector(zap.NewNop(), factories, "test")
+	// Replace collector logger with an observed core at INFO level.
+	collectorObservedCore, collectorLogs := observer.New(zapcore.InfoLevel)
+	collector.logger = zap.New(collectorObservedCore)
+
+	ctx := context.Background()
+	err = collector.Start(ctx)
+	require.NoError(t, err)
+
+	err = collector.Stop()
+	require.NoError(t, err)
+
+	// If the collector config log level is respected, there are no INFO logs
+	infoLogs := collectorLogs.FilterLevelExact(zapcore.InfoLevel).All()
+	assert.Empty(t, infoLogs,
+		"INFO logs from the collector should be suppressed when config sets level: error")
+}

collector/internal/collector/testdata/config-error-level.yaml

@@ -0,0 +1,14 @@
+receivers:
+  nop:
+
+exporters:
+  nop:
+
+service:
+  telemetry:
+    logs:
+      level: error
+  pipelines:
+    traces:
+      receivers: [nop]
+      exporters: [nop]