go.opentelemetry.io/otel v1.37.0: GetTracerProvider, Tracer, SetTracerProvider

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@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel@v1.37.0

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:sha256:9c9d69c5dc001afe7e38545d32acc63843c298742adad6aea05dde2e62bc3edc","contract":["otel.GetTracerProvider returns a non-nil default TracerProvider","otel.Tracer creates a named Tracer configured with instrumentation version option","NewTraceHolder starts spans, attaches attributes, records events and errors, and ends spans","otel.SetTracerProvider updates the global TracerProvider instance"],"goal":"verify pkg:golang/go.opentelemetry.io/otel@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel@v1.37.0"],"schemaVersion":1,"symbols":["otel.GetTracerProvider","otel.Tracer","otel.SetTracerProvider"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel@v1.37.0","symbols":["otel.GetTracerProvider","otel.Tracer","otel.SetTracerProvider"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	go.opentelemetry.io/otel v1.37.0
	go.opentelemetry.io/otel/trace v1.37.0
)

require (
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
	go.opentelemetry.io/otel/metric v1.37.0 // indirect
)

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 v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
go.opentelemetry.io/otel v1.37.0 h1:9zhNfelUvx0KBfu/gb+ZgeAfAgtWrfHJZcAqFC228wQ=
go.opentelemetry.io/otel v1.37.0/go.mod h1:ehE/umFRLnuLa/vSccNq9oS1ErUlkkK71gMcN34UG8I=
go.opentelemetry.io/otel/metric v1.37.0 h1:mvwbQS5m0tbmqML4NqK+e3aDiO02vsf/WgbsdpcPoZE=
go.opentelemetry.io/otel/metric v1.37.0/go.mod h1:04wGrZurHYKOc+RKeye86GwKiTb9FKm1WHtO+4EVr2E=
go.opentelemetry.io/otel/trace v1.37.0 h1:HLdcFNbRQBE2imdSEgm/kwqmQj1Or1l/7bW6mxVK7z4=
go.opentelemetry.io/otel/trace v1.37.0/go.mod h1:TlgrlQ+PtQO5XFerSPUYG0JSgGyryXewPGyayAWSBS0=
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"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/trace"
)

// TraceHolder wraps a Tracer created via otel.Tracer.
type TraceHolder struct {
	Tracer trace.Tracer
}

// NewTraceHolder creates a TraceHolder using the global TracerProvider.
func NewTraceHolder(name string, opts ...trace.TracerOption) (*TraceHolder, error) {
	if name == "" {
		return nil, fmt.Errorf("tracer name must not be empty")
	}
	tr := otel.Tracer(name, opts...)
	if tr == nil {
		return nil, fmt.Errorf("failed to obtain tracer")
	}
	return &TraceHolder{
		Tracer: tr,
	}, nil
}

// ExecuteSpan starts a span, executes work, records events, attributes, and errors if any, then ends the span.
func (h *TraceHolder) ExecuteSpan(ctx context.Context, spanName string, fn func(ctx context.Context, span trace.Span) error, attrs ...attribute.KeyValue) (err error) {
	if h == nil || h.Tracer == nil {
		return fmt.Errorf("trace holder or tracer is nil")
	}
	ctx, span := h.Tracer.Start(ctx, spanName, trace.WithAttributes(attrs...))
	defer span.End()

	span.AddEvent("operation_start")

	if fn != nil {
		if err = fn(ctx, span); err != nil {
			span.RecordError(err)
			span.SetStatus(codes.Error, err.Error())
			return err
		}
	}

	span.SetStatus(codes.Ok, "success")
	span.AddEvent("operation_end")
	return nil
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/go.opentelemetry.io/otel@v1.37.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel@v1.37.0"
  ],
  "symbols": [
    "otel.GetTracerProvider",
    "otel.Tracer",
    "otel.SetTracerProvider"
  ]
}

package main

import (
	"context"
	"errors"
	"fmt"
	"os"

	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/trace"
	"go.opentelemetry.io/otel/trace/noop"
	"sample"
)

func main() {
	if err := runTests(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All OpenTelemetry otel tracer contract tests passed successfully.")
}

func runTests() error {
	ctx := context.Background()

	// 1. otel.GetTracerProvider returns a non-nil default TracerProvider
	origTP := otel.GetTracerProvider()
	if origTP == nil {
		return fmt.Errorf("expected non-nil default TracerProvider from otel.GetTracerProvider")
	}

	// 2. otel.Tracer creates a named Tracer configured with instrumentation version option
	tracer := otel.Tracer(
		"example.com/contract-test",
		trace.WithInstrumentationVersion("v1.37.0"),
	)
	if tracer == nil {
		return fmt.Errorf("expected non-nil Tracer from otel.Tracer")
	}

	// 3. NewTraceHolder starts spans, attaches attributes, records events and errors, and ends spans
	holder, err := sample.NewTraceHolder(
		"example.com/contract-tracer",
		trace.WithInstrumentationVersion("v1.37.0"),
	)
	if err != nil {
		return fmt.Errorf("failed to create TraceHolder: %w", err)
	}
	if holder.Tracer == nil {
		return fmt.Errorf("expected non-nil Tracer in TraceHolder")
	}

	// Verify successful span execution
	executed := false
	err = holder.ExecuteSpan(ctx, "test-op-success", func(spanCtx context.Context, span trace.Span) error {
		executed = true
		if span == nil {
			return fmt.Errorf("expected non-nil Span")
		}
		span.SetAttributes(attribute.String("test.key", "test.value"))
		return nil
	}, attribute.String("environment", "test"))
	if err != nil {
		return fmt.Errorf("unexpected error in ExecuteSpan: %w", err)
	}
	if !executed {
		return fmt.Errorf("expected span function to be executed")
	}

	// Verify error recording during span execution
	testErr := errors.New("simulated error")
	err = holder.ExecuteSpan(ctx, "test-op-failure", func(spanCtx context.Context, span trace.Span) error {
		return testErr
	})
	if !errors.Is(err, testErr) {
		return fmt.Errorf("expected simulated error to be returned, got: %v", err)
	}

	// 4. otel.SetTracerProvider updates the global TracerProvider instance
	customTP := noop.NewTracerProvider()
	otel.SetTracerProvider(customTP)
	defer otel.SetTracerProvider(origTP)

	updatedTP := otel.GetTracerProvider()
	if updatedTP != customTP {
		return fmt.Errorf("expected GetTracerProvider to return registered custom provider")
	}

	return nil
}