Begin prototyping Log API/SDK

example/namedtracer/foo/foo.go

@@ -19,6 +19,7 @@ import (
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/log"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -28,16 +29,18 @@ var (
 
 // SubOperation is an example to demonstrate the use of named tracer.
 // It creates a named tracer with its package path.
-func SubOperation(ctx context.Context) error {
+func SubOperation(ctx context.Context, logger log.Logger) error {
 	// Using global provider. Alternative is to have application provide a getter
 	// for its component to get the instance of the provider.
 	tr := otel.Tracer("example/namedtracer/foo")
 
 	var span trace.Span
-	_, span = tr.Start(ctx, "Sub operation...")
+	ctx, span = tr.Start(ctx, "Sub operation...")
 	defer span.End()
 	span.SetAttributes(lemonsKey.String("five"))
 	span.AddEvent("Sub span event")
 
+	logger.Emit(ctx, log.WithAttributes(attribute.String("operation", "suboperation")))
+
 	return nil
 }

example/namedtracer/go.mod

@@ -2,10 +2,7 @@ module go.opentelemetry.io/otel/example/namedtracer
 
 go 1.18
 
-replace (
-	go.opentelemetry.io/otel => ../..
-	go.opentelemetry.io/otel/sdk => ../../sdk
-)
+replace go.opentelemetry.io/otel => ../..
 
 require (
 	github.com/go-logr/stdr v1.2.2
@@ -17,9 +14,17 @@ require (
 
 require (
 	github.com/go-logr/logr v1.2.3 // indirect
+	go.opentelemetry.io/otel/exporters/stdout/stdoutlog v0.0.0-00010101000000-000000000000 // indirect
+	go.opentelemetry.io/otel/log v0.0.0-00010101000000-000000000000 // indirect
 	golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 // indirect
 )
 
 replace go.opentelemetry.io/otel/trace => ../../trace
 
+replace go.opentelemetry.io/otel/log => ../../log
+
+replace go.opentelemetry.io/otel/sdk => ../../sdk
+
 replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../../exporters/stdout/stdouttrace
+
+replace go.opentelemetry.io/otel/exporters/stdout/stdoutlog => ../../exporters/stdout/stdoutlog

example/namedtracer/main.go

@@ -25,7 +25,10 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/baggage"
 	"go.opentelemetry.io/otel/example/namedtracer/foo"
+	"go.opentelemetry.io/otel/exporters/stdout/stdoutlog"
 	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
+	otellog "go.opentelemetry.io/otel/log"
+	sdklog "go.opentelemetry.io/otel/sdk/log"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/trace"
 )
@@ -37,6 +40,7 @@ var (
 )
 
 var tp *sdktrace.TracerProvider
+var lp *sdklog.LoggerProvider
 
 // initTracer creates and registers trace provider instance.
 func initTracer() error {
@@ -53,6 +57,20 @@ func initTracer() error {
 	return nil
 }
 
+// initLogger creates and registers logger provider instance.
+func initLogger() error {
+	exp, err := stdoutlog.New(stdoutlog.WithPrettyPrint())
+	if err != nil {
+		return fmt.Errorf("failed to initialize stdoutlog exporter: %w", err)
+	}
+	bsp := sdklog.NewBatchLogRecordProcessor(exp)
+	lp = sdklog.NewLoggerProvider(
+		sdklog.WithLogRecordProcessor(bsp),
+	)
+	//otel.SetTracerProvider(tp)
+	return nil
+}
+
 func main() {
 	// Set logging level to info to see SDK status messages
 	stdr.SetVerbosity(5)
@@ -61,11 +79,16 @@ func main() {
 	if err := initTracer(); err != nil {
 		log.Panic(err)
 	}
+	// initialize logger provider.
+	if err := initLogger(); err != nil {
+		log.Panic(err)
+	}
 
 	// Create a named tracer with package path as its name.
 	tracer := tp.Tracer("example/namedtracer/main")
 	ctx := context.Background()
 	defer func() { _ = tp.Shutdown(ctx) }()
+	defer func() { _ = lp.Shutdown(ctx) }()
 
 	m0, _ := baggage.NewMember(string(fooKey), "foo1")
 	m1, _ := baggage.NewMember(string(barKey), "bar1")
@@ -77,7 +100,11 @@ func main() {
 	defer span.End()
 	span.AddEvent("Nice operation!", trace.WithAttributes(attribute.Int("bogons", 100)))
 	span.SetAttributes(anotherKey.String("yes"))
-	if err := foo.SubOperation(ctx); err != nil {
+
+	logger := lp.Logger("example/namedtracer/main")
+	logger.Emit(ctx, otellog.WithAttributes(attribute.String("operation", "main")))
+
+	if err := foo.SubOperation(ctx, logger); err != nil {
 		panic(err)
 	}
 }

exporters/stdout/stdoutlog/config.go

@@ -0,0 +1,96 @@
+// 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 stdoutlog // import "go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
+
+import (
+	"io"
+	"os"
+)
+
+var (
+	defaultWriter      = os.Stdout
+	defaultPrettyPrint = false
+	defaultTimestamps  = true
+)
+
+// config contains options for the STDOUT exporter.
+type config struct {
+	// Writer is the destination.  If not set, os.Stdout is used.
+	Writer io.Writer
+
+	// PrettyPrint will encode the output into readable JSON. Default is
+	// false.
+	PrettyPrint bool
+
+	// Timestamps specifies if timestamps should be printed. Default is
+	// true.
+	Timestamps bool
+}
+
+// newConfig creates a validated Config configured with options.
+func newConfig(options ...Option) (config, error) {
+	cfg := config{
+		Writer:      defaultWriter,
+		PrettyPrint: defaultPrettyPrint,
+		Timestamps:  defaultTimestamps,
+	}
+	for _, opt := range options {
+		cfg = opt.apply(cfg)
+	}
+	return cfg, nil
+}
+
+// Option sets the value of an option for a Config.
+type Option interface {
+	apply(config) config
+}
+
+// WithWriter sets the export stream destination.
+func WithWriter(w io.Writer) Option {
+	return writerOption{w}
+}
+
+type writerOption struct {
+	W io.Writer
+}
+
+func (o writerOption) apply(cfg config) config {
+	cfg.Writer = o.W
+	return cfg
+}
+
+// WithPrettyPrint sets the export stream format to use JSON.
+func WithPrettyPrint() Option {
+	return prettyPrintOption(true)
+}
+
+type prettyPrintOption bool
+
+func (o prettyPrintOption) apply(cfg config) config {
+	cfg.PrettyPrint = bool(o)
+	return cfg
+}
+
+// WithoutTimestamps sets the export stream to not include timestamps.
+func WithoutTimestamps() Option {
+	return timestampsOption(false)
+}
+
+type timestampsOption bool
+
+func (o timestampsOption) apply(cfg config) config {
+	cfg.Timestamps = bool(o)
+	return cfg
+}

exporters/stdout/stdoutlog/doc.go

@@ -0,0 +1,17 @@
+// 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 stdouttrace contains an OpenTelemetry exporter for tracing
+// telemetry to be written to an output destination as JSON.
+package stdoutlog // import "go.opentelemetry.io/otel/exporters/stdout/stdouttrace"

exporters/stdout/stdoutlog/go.mod

@@ -0,0 +1,23 @@
+module go.opentelemetry.io/otel/exporters/stdout/stdoutlog
+
+go 1.18
+
+replace (
+	go.opentelemetry.io/otel => ../../..
+	go.opentelemetry.io/otel/sdk => ../../../sdk
+)
+
+require go.opentelemetry.io/otel/sdk v1.11.2
+
+require (
+	github.com/go-logr/logr v1.2.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	go.opentelemetry.io/otel v1.11.2 // indirect
+	go.opentelemetry.io/otel/log v0.0.0-00010101000000-000000000000 // indirect
+	go.opentelemetry.io/otel/trace v1.11.2 // indirect
+	golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 // indirect
+)
+
+replace go.opentelemetry.io/otel/log => ../../../log
+
+replace go.opentelemetry.io/otel/sdk/log => ../../../sdk/log

exporters/stdout/stdoutlog/go.sum

@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
+go.opentelemetry.io/otel/trace v1.11.2 h1:Xf7hWSF2Glv0DE3MH7fBHvtpSBsjcBUe5MYAmZM/+y0=
+go.opentelemetry.io/otel/trace v1.11.2/go.mod h1:4N+yC7QEz7TTsG9BSRLNAa63eg5E06ObSbKPmxQ/pKA=
+golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8 h1:h+EGohizhe9XlX18rfpa8k8RAc5XyaeamM+0VHRd4lc=
+golang.org/x/sys v0.0.0-20220919091848-fb04ddd9f9c8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

exporters/stdout/stdoutlog/log.go

@@ -0,0 +1,114 @@
+// 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 stdoutlog // import "go.opentelemetry.io/otel/exporters/stdout/stdoutlog"
+
+import (
+	"context"
+	"encoding/json"
+	"sync"
+	"time"
+
+	"go.opentelemetry.io/otel/sdk/log"
+	"go.opentelemetry.io/otel/sdk/log/logtest"
+)
+
+var zeroTime time.Time
+
+var _ log.LogRecordExporter = &Exporter{}
+
+// New creates an Exporter with the passed options.
+func New(options ...Option) (*Exporter, error) {
+	cfg, err := newConfig(options...)
+	if err != nil {
+		return nil, err
+	}
+
+	enc := json.NewEncoder(cfg.Writer)
+	if cfg.PrettyPrint {
+		enc.SetIndent("", "\t")
+	}
+
+	return &Exporter{
+		encoder:    enc,
+		timestamps: cfg.Timestamps,
+	}, nil
+}
+
+// Exporter is an implementation of trace.SpanSyncer that writes spans to stdout.
+type Exporter struct {
+	encoder    *json.Encoder
+	encoderMu  sync.Mutex
+	timestamps bool
+
+	stoppedMu sync.RWMutex
+	stopped   bool
+}
+
+// ExportLogRecords writes spans in json format to stdout.
+func (e *Exporter) ExportLogRecords(ctx context.Context, spans []log.ReadOnlyLogRecord) error {
+	e.stoppedMu.RLock()
+	stopped := e.stopped
+	e.stoppedMu.RUnlock()
+	if stopped {
+		return nil
+	}
+
+	if len(spans) == 0 {
+		return nil
+	}
+
+	stubs := logtest.LogRecordStubsFromReadOnlyLogRecords(spans)
+
+	e.encoderMu.Lock()
+	defer e.encoderMu.Unlock()
+	for i := range stubs {
+		stub := &stubs[i]
+		// Remove timestamps
+		if !e.timestamps {
+			stub.Timestamp = zeroTime
+		}
+
+		// Encode span stubs, one by one
+		if err := e.encoder.Encode(stub); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Shutdown is called to stop the exporter, it preforms no action.
+func (e *Exporter) Shutdown(ctx context.Context) error {
+	e.stoppedMu.Lock()
+	e.stopped = true
+	e.stoppedMu.Unlock()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+	}
+	return nil
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this exporter.
+func (e *Exporter) MarshalLog() interface{} {
+	return struct {
+		Type           string
+		WithTimestamps bool
+	}{
+		Type:           "stdout",
+		WithTimestamps: e.timestamps,
+	}
+}