go.opentelemetry.io/otel/metric v1.37.0

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/metric@v1.37.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.opentelemetry.io/otel/metric@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:sha256:8928846507814ffc133b974be0835e9c0c567736258aa81784992076210ff773","contract":["MeterProvider creates Meter instances with instrumentation configuration","Meter creates Int64Counter and records measurements","Meter creates Float64ObservableGauge and registers observer callback","Meter creates Float64Histogram and records distributions","NewMeterConfig applies instrumentation version and schema URL options"],"goal":"verify pkg:golang/go.opentelemetry.io/otel/metric@v1.37.0","kind":"HOW","packages":["pkg:golang/go.opentelemetry.io/otel/metric@v1.37.0"],"schemaVersion":1},"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/metric@v1.37.0"],"schemaVersion":1,"subject":"pkg:golang/go.opentelemetry.io/otel/metric@v1.37.0","verifierAdapter":"golang@1"}

module example.com/otel-metric-sample

go 1.26.6

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

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 v1.4.3 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 main

import (
	"context"
	"fmt"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

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

	cfg := metric.NewMeterConfig(
		metric.WithInstrumentationVersion("1.37.0"),
		metric.WithSchemaURL("https://example.com/schemas/1.37.0"),
		metric.WithInstrumentationAttributes(
			attribute.String("service.name", "demo-service"),
		),
	)

	provider := noop.NewMeterProvider()
	meter := provider.Meter(
		"example.com/metric-sample",
		metric.WithInstrumentationVersion(cfg.InstrumentationVersion()),
		metric.WithSchemaURL(cfg.SchemaURL()),
	)

	counter, err := meter.Int64Counter(
		"sample_requests_total",
		metric.WithDescription("Total number of processed sample requests"),
		metric.WithUnit("{request}"),
	)
	if err != nil {
		panic(err)
	}
	counter.Add(ctx, 1)

	gauge, err := meter.Float64ObservableGauge(
		"sample_cpu_utilization",
		metric.WithDescription("CPU utilization between 0 and 1"),
		metric.WithUnit("1"),
	)
	if err != nil {
		panic(err)
	}

	reg, err := meter.RegisterCallback(
		func(ctx context.Context, obs metric.Observer) error {
			obs.ObserveFloat64(gauge, 0.42)
			return nil
		},
		gauge,
	)
	if err != nil {
		panic(err)
	}
	defer reg.Unregister()

	histogram, err := meter.Float64Histogram(
		"sample_latency_seconds",
		metric.WithDescription("Request latency in seconds"),
		metric.WithUnit("s"),
	)
	if err != nil {
		panic(err)
	}
	histogram.Record(ctx, 0.123)

	fmt.Println("OpenTelemetry metric sample executed successfully.")
}

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

package main

import (
	"context"
	"fmt"
	"os"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/metric/noop"
)

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

	// 1. MeterProvider creates Meter instances with instrumentation configuration
	mp := noop.NewMeterProvider()
	meter := mp.Meter(
		"example.com/contract-meter",
		metric.WithInstrumentationVersion("1.37.0"),
		metric.WithSchemaURL("https://example.com/schemas/1.37.0"),
	)
	if meter == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Meter from MeterProvider\n")
		os.Exit(1)
	}

	// 2. Meter creates Int64Counter and records measurements
	counter, err := meter.Int64Counter(
		"contract_requests_total",
		metric.WithDescription("Total test requests"),
		metric.WithUnit("{request}"),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error creating Int64Counter: %v\n", err)
		os.Exit(1)
	}
	if counter == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Int64Counter\n")
		os.Exit(1)
	}
	counter.Add(ctx, 1)
	counter.Add(ctx, 42)

	// 3. Meter creates Float64ObservableGauge and registers observer callback
	var gaugeObserved float64
	gauge, err := meter.Float64ObservableGauge(
		"contract_memory_utilization",
		metric.WithDescription("Memory utilization ratio"),
		metric.WithUnit("1"),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error creating Float64ObservableGauge: %v\n", err)
		os.Exit(1)
	}
	if gauge == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Float64ObservableGauge\n")
		os.Exit(1)
	}

	reg, err := meter.RegisterCallback(
		func(ctx context.Context, obs metric.Observer) error {
			obs.ObserveFloat64(gauge, 0.75)
			gaugeObserved = 0.75
			return nil
		},
		gauge,
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error registering callback: %v\n", err)
		os.Exit(1)
	}
	_ = gaugeObserved
	if err := reg.Unregister(); err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error unregistering callback: %v\n", err)
		os.Exit(1)
	}

	// 4. Meter creates Float64Histogram and records distributions
	histogram, err := meter.Float64Histogram(
		"contract_request_latency",
		metric.WithDescription("Request latency distribution"),
		metric.WithUnit("ms"),
	)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error creating Float64Histogram: %v\n", err)
		os.Exit(1)
	}
	if histogram == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Float64Histogram\n")
		os.Exit(1)
	}
	histogram.Record(ctx, 15.5)
	histogram.Record(ctx, 88.2)

	// 5. NewMeterConfig applies instrumentation version and schema URL options
	cfg := metric.NewMeterConfig(
		metric.WithInstrumentationVersion("1.37.0"),
		metric.WithSchemaURL("https://example.com/schemas/1.37.0"),
		metric.WithInstrumentationAttributes(
			attribute.String("test.component", "contract-runner"),
		),
	)
	if cfg.InstrumentationVersion() != "1.37.0" {
		fmt.Fprintf(os.Stderr, "expected version 1.37.0, got %q\n", cfg.InstrumentationVersion())
		os.Exit(1)
	}
	if cfg.SchemaURL() != "https://example.com/schemas/1.37.0" {
		fmt.Fprintf(os.Stderr, "expected schema URL, got %q\n", cfg.SchemaURL())
		os.Exit(1)
	}
	attrs := cfg.InstrumentationAttributes()
	if attrs.Len() != 1 {
		fmt.Fprintf(os.Stderr, "expected 1 attribute, got %d\n", attrs.Len())
		os.Exit(1)
	}

	fmt.Println("All otel/metric contract assertions passed successfully.")
}