go.opentelemetry.io/otel v1.43.0: Version, Meter, SetLogger

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 pkg:golang/go.opentelemetry.io/otel@v1.43.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel@v1.43.0
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:sha256:44e2602ce7b80d10c166291fc015a6f06690d067ff617a4ee969d1ae0757b745","contract":["otel.Version returns the release version string for OpenTelemetry matching 1.43.0","otel.Meter creates a named Meter delegating to the configured MeterProvider","otel.SetLogger configures the global logger used internally by OpenTelemetry","otel.ErrorHandlerFunc adapts a function to the ErrorHandler interface and otel.GetErrorHandler returns the active handler"],"goal":"verify pkg:golang/go.opentelemetry.io/otel@v1.43.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel@v1.43.0"],"schemaVersion":1,"symbols":["Version","Meter","SetLogger","GetErrorHandler","ErrorHandlerFunc"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel@v1.43.0"],"schemaVersion":1,"symbols":["Version","Meter","SetLogger","GetErrorHandler","ErrorHandlerFunc"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require (
	github.com/go-logr/stdr v1.2.2
	go.opentelemetry.io/otel v1.43.0
	go.opentelemetry.io/otel/metric v1.43.0
)

require (
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/otel/trace v1.43.0 // 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/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/metric v1.43.0 h1:d7638QeInOnuwOONPp4JAOGfbCEpYb+K6DVWvdxGzgM=
go.opentelemetry.io/otel/metric v1.43.0/go.mod h1:RDnPtIxvqlgO8GRW18W6Z/4P462ldprJtfxHxyKd2PY=
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=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"context"
	"errors"
	"fmt"
	"log"
	"os"
	"sync/atomic"

	"github.com/go-logr/stdr"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

// MetricsService manages metric instrumentation and error handling.
type MetricsService struct {
	meter metric.Meter
}

// NewMetricsService sets up telemetry infrastructure with custom logger and meter provider.
func NewMetricsService(name string) *MetricsService {
	// Configure internal logger for OpenTelemetry diagnostics
	logger := stdr.New(log.New(os.Stdout, "", log.LstdFlags|log.Lshortfile))
	otel.SetLogger(logger)

	// Set global meter provider
	otel.SetMeterProvider(noop.NewMeterProvider())

	return &MetricsService{
		meter: otel.Meter(name),
	}
}

// RecordOperation records metrics for an executed operation.
func (s *MetricsService) RecordOperation(ctx context.Context, duration float64) error {
	counter, err := s.meter.Int64Counter("operations_total")
	if err != nil {
		otel.Handle(err)
		return err
	}
	counter.Add(ctx, 1)

	histogram, err := s.meter.Float64Histogram("operation_duration_seconds")
	if err != nil {
		otel.Handle(err)
		return err
	}
	histogram.Record(ctx, duration)
	return nil
}

func main() {
	fmt.Printf("OpenTelemetry version: %s\n", otel.Version())

	var errorCount int64
	errorHandler := otel.ErrorHandlerFunc(func(err error) {
		atomic.AddInt64(&errorCount, 1)
		fmt.Printf("Custom error handler captured: %v\n", err)
	})
	otel.SetErrorHandler(errorHandler)

	svc := NewMetricsService("example.com/metrics-service")
	ctx := context.Background()

	if err := svc.RecordOperation(ctx, 0.05); err != nil {
		otel.Handle(err)
	}

	handler := otel.GetErrorHandler()
	handler.Handle(errors.New("simulated error dispatched to global handler"))

	fmt.Printf("Sample execution finished, errors handled: %d\n", atomic.LoadInt64(&errorCount))
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/go.opentelemetry.io/otel@v1.43.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel@v1.43.0"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

package main

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"log"
	"os"
	"strings"
	"sync"
	"sync/atomic"

	"github.com/go-logr/stdr"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/metric/noop"
)

func main() {
	// Contract 1: otel.Version returns the release version string for OpenTelemetry matching 1.43.0
	{
		v := otel.Version()
		if v == "" {
			fmt.Fprintln(os.Stderr, "FAIL: expected non-empty version string from otel.Version()")
			os.Exit(1)
		}
		if v != "1.43.0" {
			fmt.Fprintf(os.Stderr, "FAIL: expected version '1.43.0', got '%s'\n", v)
			os.Exit(1)
		}
	}

	// Contract 2: otel.Meter creates a named Meter delegating to the configured MeterProvider
	{
		mp := noop.NewMeterProvider()
		otel.SetMeterProvider(mp)

		meter := otel.Meter("contract-metrics")
		if meter == nil {
			fmt.Fprintln(os.Stderr, "FAIL: expected non-nil Meter from otel.Meter()")
			os.Exit(1)
		}

		ctx := context.Background()
		counter, err := meter.Int64Counter("contract_counter")
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: failed to create Int64Counter: %v\n", err)
			os.Exit(1)
		}
		counter.Add(ctx, 42)

		histogram, err := meter.Float64Histogram("contract_histogram")
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: failed to create Float64Histogram: %v\n", err)
			os.Exit(1)
		}
		histogram.Record(ctx, 1.23)
	}

	// Contract 3: otel.SetLogger configures the global logger used internally by OpenTelemetry
	{
		var logBuf bytes.Buffer
		var logMu sync.Mutex

		writer := &syncWriter{buf: &logBuf, mu: &logMu}
		stdLogger := log.New(writer, "[otel-test] ", 0)
		logger := stdr.New(stdLogger)

		otel.SetLogger(logger)
	}

	// Contract 4: otel.ErrorHandlerFunc adapts a function to the ErrorHandler interface and otel.GetErrorHandler returns the active handler
	{
		var capturedErr error
		var handleCount int64

		fn := otel.ErrorHandlerFunc(func(err error) {
			atomic.AddInt64(&handleCount, 1)
			capturedErr = err
		})

		otel.SetErrorHandler(fn)
		activeHandler := otel.GetErrorHandler()
		if activeHandler == nil {
			fmt.Fprintln(os.Stderr, "FAIL: expected non-nil ErrorHandler from otel.GetErrorHandler()")
			os.Exit(1)
		}

		testErr := errors.New("contract-error-dispatch")
		activeHandler.Handle(testErr)

		if atomic.LoadInt64(&handleCount) != 1 {
			fmt.Fprintf(os.Stderr, "FAIL: expected ErrorHandlerFunc to be called once, got %d\n", atomic.LoadInt64(&handleCount))
			os.Exit(1)
		}
		if capturedErr == nil || !strings.Contains(capturedErr.Error(), "contract-error-dispatch") {
			fmt.Fprintf(os.Stderr, "FAIL: expected error containing 'contract-error-dispatch', got %v\n", capturedErr)
			os.Exit(1)
		}
	}

	fmt.Println("PASS: pkg:golang/go.opentelemetry.io/otel@v1.43.0 contract verified")
}

type syncWriter struct {
	buf *bytes.Buffer
	mu  *sync.Mutex
}

func (w *syncWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	return w.buf.Write(p)
}