go.opentelemetry.io/otel/sdk/log v0.19.0: LoggerProvider

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify go.opentelemetry.io/otel/sdk/log.LoggerProvider in pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/sdk/log.LoggerProvider
Required runtime conditions:
  - ecosystem: golang
  - language: go
  - packageManager: go@1.26.6
  - runtime: go@1.26.6

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:2574667aa8434cdf6d3467be7fadd1313925fd1ff70a2967e3305551ddcedea9","contract":["LoggerProvider configures log processors and resource metadata via functional options","LoggerProvider creates named Logger instances associated with provider resource","Logger instances emit structured log records with severity, body, and attributes to registered exporter","LoggerProvider ForceFlush flushes unexported records across registered processors","LoggerProvider Shutdown terminates processors and cleanly releases exporter resources"],"goal":"verify go.opentelemetry.io/otel/sdk/log.LoggerProvider in pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/sdk/log.LoggerProvider"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0","symbols":["go.opentelemetry.io/otel/sdk/log.LoggerProvider"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

require (
	go.opentelemetry.io/otel v1.43.0
	go.opentelemetry.io/otel/log v0.19.0
	go.opentelemetry.io/otel/sdk v1.43.0
	go.opentelemetry.io/otel/sdk/log v0.19.0
)

require (
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/uuid v1.6.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel/metric v1.43.0 // indirect
	go.opentelemetry.io/otel/trace v1.43.0 // indirect
	golang.org/x/sys v0.42.0 // indirect
)

github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
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 v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/otel v1.43.0 h1:mYIM03dnh5zfN7HautFE4ieIig9amkNANT+xcVxAj9I=
go.opentelemetry.io/otel v1.43.0/go.mod h1:JuG+u74mvjvcm8vj8pI5XiHy1zDeoCS2LB1spIq7Ay0=
go.opentelemetry.io/otel/log v0.19.0 h1:KUZs/GOsw79TBBMfDWsXS+KZ4g2Ckzksd1ymzsIEbo4=
go.opentelemetry.io/otel/log v0.19.0/go.mod h1:5DQYeGmxVIr4n0/BcJvF4upsraHjg6vudJJpnkL6Ipk=
go.opentelemetry.io/otel/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
go.opentelemetry.io/otel/sdk v1.43.0 h1:pi5mE86i5rTeLXqoF/hhiBtUNcrAGHLKQdhg4h4V9Dg=
go.opentelemetry.io/otel/sdk v1.43.0/go.mod h1:P+IkVU3iWukmiit/Yf9AWvpyRDlUeBaRg6Y+C58QHzg=
go.opentelemetry.io/otel/sdk/log v0.19.0 h1:scYVLqT22D2gqXItnWiocLUKGH9yvkkeql5dBDiXyko=
go.opentelemetry.io/otel/sdk/log v0.19.0/go.mod h1:vFBowwXGLlW9AvpuF7bMgnNI95LiW10szrOdvzBHlAg=
go.opentelemetry.io/otel/sdk/metric v1.43.0 h1:S88dyqXjJkuBNLeMcVPRFXpRw2fuwdvfCGLEo89fDkw=
go.opentelemetry.io/otel/sdk/metric v1.43.0/go.mod h1:C/RJtwSEJ5hzTiUz5pXF1kILHStzb9zFlIEe85bhj6A=
go.opentelemetry.io/otel/trace v1.43.0 h1:BkNrHpup+4k4w+ZZ86CZoHHEkohws8AY+WTX09nk+3A=
go.opentelemetry.io/otel/trace v1.43.0/go.mod h1:/QJhyVBUUswCphDVxq+8mld+AvhXZLhe+8WVFxiFff0=
golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"context"
	"fmt"
	"sync"
	"time"

	"go.opentelemetry.io/otel/log"
	sdklog "go.opentelemetry.io/otel/sdk/log"
	"go.opentelemetry.io/otel/sdk/resource"
	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
)

// InMemoryExporter captures exported log records in-memory for verification.
type InMemoryExporter struct {
	mu          sync.Mutex
	records     []sdklog.Record
	isShutdown  bool
	flushCalled int
}

// Export stores a copy of the emitted log records.
func (e *InMemoryExporter) Export(ctx context.Context, records []sdklog.Record) error {
	e.mu.Lock()
	defer e.mu.Unlock()
	if e.isShutdown {
		return fmt.Errorf("exporter is shut down")
	}
	for _, r := range records {
		e.records = append(e.records, r.Clone())
	}
	return nil
}

// Shutdown marks the exporter as closed.
func (e *InMemoryExporter) Shutdown(ctx context.Context) error {
	e.mu.Lock()
	defer e.mu.Unlock()
	e.isShutdown = true
	return nil
}

// ForceFlush records that a flush occurred.
func (e *InMemoryExporter) ForceFlush(ctx context.Context) error {
	e.mu.Lock()
	defer e.mu.Unlock()
	if e.isShutdown {
		return fmt.Errorf("exporter is shut down")
	}
	e.flushCalled++
	return nil
}

// Records returns a slice copy of all captured log records.
func (e *InMemoryExporter) Records() []sdklog.Record {
	e.mu.Lock()
	defer e.mu.Unlock()
	res := make([]sdklog.Record, len(e.records))
	copy(res, e.records)
	return res
}

// IsShutdown returns whether Shutdown was called on the exporter.
func (e *InMemoryExporter) IsShutdown() bool {
	e.mu.Lock()
	defer e.mu.Unlock()
	return e.isShutdown
}

// FlushCount returns how many times ForceFlush was called.
func (e *InMemoryExporter) FlushCount() int {
	e.mu.Lock()
	defer e.mu.Unlock()
	return e.flushCalled
}

// NewConfiguredLoggerProvider creates a LoggerProvider configured with a Resource and SimpleProcessor.
func NewConfiguredLoggerProvider(exporter sdklog.Exporter, serviceName string, opts ...sdklog.LoggerProviderOption) *sdklog.LoggerProvider {
	res := resource.NewWithAttributes(
		semconv.SchemaURL,
		semconv.ServiceNameKey.String(serviceName),
	)

	defaultOpts := []sdklog.LoggerProviderOption{
		sdklog.WithResource(res),
	}

	if exporter != nil {
		processor := sdklog.NewSimpleProcessor(exporter)
		defaultOpts = append(defaultOpts, sdklog.WithProcessor(processor))
	}

	allOpts := append(defaultOpts, opts...)
	return sdklog.NewLoggerProvider(allOpts...)
}

// EmitLog creates and emits a record with severity, body, and attributes to the logger.
func EmitLog(ctx context.Context, logger log.Logger, severity log.Severity, severityText string, body string, attrs ...log.KeyValue) {
	var r log.Record
	r.SetTimestamp(time.Now())
	r.SetObservedTimestamp(time.Now())
	r.SetSeverity(severity)
	r.SetSeverityText(severityText)
	r.SetBody(log.StringValue(body))
	r.AddAttributes(attrs...)

	logger.Emit(ctx, r)
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/sdk/log.LoggerProvider in pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/sdk/log@v0.19.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/sdk/log.LoggerProvider"
  ],
  "runtimeConditions": {
    "ecosystem": "golang",
    "language": "go",
    "packageManager": "go@1.26.6",
    "runtime": "go@1.26.6"
  }
}

package main

import (
	"context"
	"fmt"
	"os"

	"sample"
	"go.opentelemetry.io/otel/log"
	sdklog "go.opentelemetry.io/otel/sdk/log"
	"go.opentelemetry.io/otel/sdk/resource"
	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
)

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

	// 1. LoggerProvider configures log processors and resource metadata via functional options
	exporter := &sample.InMemoryExporter{}
	res := resource.NewWithAttributes(
		semconv.SchemaURL,
		semconv.ServiceNameKey.String("test-service"),
	)
	processor := sdklog.NewSimpleProcessor(exporter)
	lp := sdklog.NewLoggerProvider(
		sdklog.WithProcessor(processor),
		sdklog.WithResource(res),
	)
	if lp == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil LoggerProvider\n")
		os.Exit(1)
	}

	// 2. LoggerProvider creates named Logger instances associated with provider resource
	loggerName := "example.com/test-logger"
	logger := lp.Logger(loggerName)
	if logger == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Logger from LoggerProvider.Logger\n")
		os.Exit(1)
	}

	// 3. Logger instances emit structured log records with severity, body, and attributes to registered exporter
	sample.EmitLog(
		ctx,
		logger,
		log.SeverityInfo,
		"INFO",
		"test log message",
		log.String("component", "auth"),
		log.Int("retry_count", 3),
	)

	records := exporter.Records()
	if len(records) != 1 {
		fmt.Fprintf(os.Stderr, "expected 1 exported record, got %d\n", len(records))
		os.Exit(1)
	}

	rec := records[0]
	if rec.Body().AsString() != "test log message" {
		fmt.Fprintf(os.Stderr, "expected body %q, got %q\n", "test log message", rec.Body().AsString())
		os.Exit(1)
	}
	if rec.Severity() != log.SeverityInfo {
		fmt.Fprintf(os.Stderr, "expected severity %v, got %v\n", log.SeverityInfo, rec.Severity())
		os.Exit(1)
	}
	if rec.SeverityText() != "INFO" {
		fmt.Fprintf(os.Stderr, "expected severity text %q, got %q\n", "INFO", rec.SeverityText())
		os.Exit(1)
	}

	// Verify attributes
	var foundComponent, foundRetry bool
	rec.WalkAttributes(func(kv log.KeyValue) bool {
		if kv.Key == "component" && kv.Value.AsString() == "auth" {
			foundComponent = true
		}
		if kv.Key == "retry_count" && kv.Value.AsInt64() == 3 {
			foundRetry = true
		}
		return true
	})
	if !foundComponent {
		fmt.Fprintf(os.Stderr, "expected attribute 'component' with value 'auth'\n")
		os.Exit(1)
	}
	if !foundRetry {
		fmt.Fprintf(os.Stderr, "expected attribute 'retry_count' with value 3\n")
		os.Exit(1)
	}

	// Verify resource attached to emitted record
	if rec.Resource() == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Resource on Record\n")
		os.Exit(1)
	}

	// 4. LoggerProvider ForceFlush flushes unexported records across registered processors
	flushErr := lp.ForceFlush(ctx)
	if flushErr != nil {
		fmt.Fprintf(os.Stderr, "expected nil error on ForceFlush, got %v\n", flushErr)
		os.Exit(1)
	}
	if exporter.FlushCount() != 1 {
		fmt.Fprintf(os.Stderr, "expected FlushCount 1, got %d\n", exporter.FlushCount())
		os.Exit(1)
	}

	// 5. LoggerProvider Shutdown terminates processors and cleanly releases exporter resources
	shutdownErr := lp.Shutdown(ctx)
	if shutdownErr != nil {
		fmt.Fprintf(os.Stderr, "expected nil error on Shutdown, got %v\n", shutdownErr)
		os.Exit(1)
	}
	if !exporter.IsShutdown() {
		fmt.Fprintf(os.Stderr, "expected exporter to be shutdown after provider.Shutdown\n")
		os.Exit(1)
	}

	// Helper verification
	helperExp := &sample.InMemoryExporter{}
	helperProvider := sample.NewConfiguredLoggerProvider(helperExp, "helper-service")
	defer func() {
		_ = helperProvider.Shutdown(ctx)
	}()
	helperLogger := helperProvider.Logger("helper-logger")
	sample.EmitLog(ctx, helperLogger, log.SeverityWarn, "WARN", "warning payload")

	helperRecords := helperExp.Records()
	if len(helperRecords) != 1 || helperRecords[0].Body().AsString() != "warning payload" {
		fmt.Fprintf(os.Stderr, "unexpected helper records\n")
		os.Exit(1)
	}

	fmt.Println("All OpenTelemetry LoggerProvider contract assertions passed.")
}