go.opentelemetry.io/otel/metric v1.24.0: MeterProvider

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/metric.MeterProvider in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0
Demonstrate these symbols/APIs:
  - go.opentelemetry.io/otel/metric.MeterProvider

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:sha256:3e6afea55f7ff2253ad654aca504fa21113da264262fd5bee1084e16744790db","contract":["metric.MeterProvider provides access to named Meter instances with configuration options","Meter creates synchronous counter and histogram instruments and records measurements","noop.NewMeterProvider satisfies metric.MeterProvider interface","custom types embedding noop.MeterProvider satisfy metric.MeterProvider and can intercept Meter creation"],"goal":"verify go.opentelemetry.io/otel/metric.MeterProvider in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"],"schemaVersion":1,"symbols":["go.opentelemetry.io/otel/metric.MeterProvider"]},"contractCommand":["go","test","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","moduleSystem":"go.mod","os":"linux","osVersionBucket":"24","packageManager":"go","runtime":"go","runtimeVersion":"1.26","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0","symbols":["go.opentelemetry.io/otel/metric.MeterProvider"],"verifierAdapter":"golang@1"}

module example.com/meterprovider-sample

go 1.26.6

require go.opentelemetry.io/otel/metric v1.24.0

require go.opentelemetry.io/otel v1.24.0 // 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 v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
github.com/go-logr/logr v1.4.1/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 v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
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 v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
go.opentelemetry.io/otel v1.24.0 h1:0LAOdjNmQeSTzGBzduGe/rU4tZhMwL5rWgtp9Ku5Jfo=
go.opentelemetry.io/otel v1.24.0/go.mod h1:W7b9Ozg4nkF5tWI5zsXkaKKDjdVjpD4oAt9Qi/MArHo=
go.opentelemetry.io/otel/metric v1.24.0 h1:6EhoGWWK28x1fbpA4tYTOWBkPefTDQnb8WSGXlc88kI=
go.opentelemetry.io/otel/metric v1.24.0/go.mod h1:VYhLe1rFfxuTXLgj4CBiyz+9WYBA8pNGJgDcSFRKBco=
go.opentelemetry.io/otel/trace v1.24.0 h1:CsKnnL4dUAr/0llH9FKuc698G04IrpWV0MQA/Y1YELI=
go.opentelemetry.io/otel/trace v1.24.0/go.mod h1:HPc3Xr/cOApsBI154IU0OI0HJexz+aw5uPdbs3UCjNU=
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/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

// SetupMeter initializes a Meter from the provided MeterProvider using name and options,
// and constructs an Int64Counter and a Float64Histogram.
func SetupMeter(mp metric.MeterProvider, name string, opts ...metric.MeterOption) (metric.Meter, metric.Int64Counter, metric.Float64Histogram, error) {
	if mp == nil {
		mp = noop.NewMeterProvider()
	}
	meter := mp.Meter(name, opts...)
	counter, err := meter.Int64Counter(
		"requests_total",
		metric.WithDescription("Total number of processed requests"),
		metric.WithUnit("1"),
	)
	if err != nil {
		return nil, nil, nil, fmt.Errorf("failed to create counter: %w", err)
	}

	histogram, err := meter.Float64Histogram(
		"request_duration_seconds",
		metric.WithDescription("Request duration in seconds"),
		metric.WithUnit("s"),
	)
	if err != nil {
		return nil, nil, nil, fmt.Errorf("failed to create histogram: %w", err)
	}

	return meter, counter, histogram, nil
}

// RecordMetrics records a count and duration measurement with attributes.
func RecordMetrics(ctx context.Context, counter metric.Int64Counter, histogram metric.Float64Histogram, count int64, duration float64) {
	if counter != nil {
		counter.Add(ctx, count)
	}
	if histogram != nil {
		histogram.Record(ctx, duration)
	}
}

{
  "schemaVersion": 1,
  "goal": "verify go.opentelemetry.io/otel/metric.MeterProvider in pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.opentelemetry.io/otel/metric@v1.24.0"
  ],
  "symbols": [
    "go.opentelemetry.io/otel/metric.MeterProvider"
  ]
}

package test

import (
	"context"
	"testing"

	sample "example.com/meterprovider-sample"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

// customMeterProvider embeds noop.MeterProvider to implement metric.MeterProvider
type customMeterProvider struct {
	noop.MeterProvider
	lastMeterName string
	callCount     int
}

func (c *customMeterProvider) Meter(name string, opts ...metric.MeterOption) metric.Meter {
	c.lastMeterName = name
	c.callCount++
	return c.MeterProvider.Meter(name, opts...)
}

func TestMeterProviderContract(t *testing.T) {
	ctx := context.Background()

	// 1. noop.NewMeterProvider satisfies metric.MeterProvider interface
	noopMP := noop.NewMeterProvider()
	var mp metric.MeterProvider = noopMP

	// 2. MeterProvider provides access to named Meter instances with configuration options
	meter, counter, histogram, err := sample.SetupMeter(
		mp,
		"example.com/test-meter",
		metric.WithInstrumentationVersion("v1.24.0"),
		metric.WithSchemaURL("https://example.com/schemas/1.0.0"),
	)
	if err != nil {
		t.Fatalf("unexpected error setting up meter: %v", err)
	}
	if meter == nil {
		t.Fatal("expected non-nil meter")
	}
	if counter == nil {
		t.Fatal("expected non-nil counter")
	}
	if histogram == nil {
		t.Fatal("expected non-nil histogram")
	}

	// 3. Meter creates synchronous counter and histogram instruments and records measurements
	sample.RecordMetrics(ctx, counter, histogram, 5, 0.123)

	// 4. Custom types embedding noop.MeterProvider satisfy metric.MeterProvider and can intercept Meter creation
	customMP := &customMeterProvider{
		MeterProvider: noopMP,
	}
	var mp2 metric.MeterProvider = customMP
	meter2, counter2, histogram2, err := sample.SetupMeter(
		mp2,
		"example.com/custom-intercepted",
		metric.WithInstrumentationVersion("v1.0.0"),
	)
	if err != nil {
		t.Fatalf("unexpected error setting up meter with custom provider: %v", err)
	}
	if meter2 == nil || counter2 == nil || histogram2 == nil {
		t.Fatal("expected non-nil meter and instruments from custom provider")
	}
	if customMP.callCount != 1 {
		t.Fatalf("expected custom provider Meter to be called once, got %d", customMP.callCount)
	}
	if customMP.lastMeterName != "example.com/custom-intercepted" {
		t.Fatalf("expected meter name %q, got %q", "example.com/custom-intercepted", customMP.lastMeterName)
	}
}