github.com/cyberdelia/go-metrics-graphite v0.0.0-20161219230853-39f87cc3b432: Config

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 github.com/cyberdelia/go-metrics-graphite.Config in pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432
Demonstrate these symbols/APIs:
  - github.com/cyberdelia/go-metrics-graphite.Config

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:cf7d33706b6458b8e1317a740ebd359a7051ed0801118167a25988d7bcb3e3f0","contract":["Config defines Graphite exporter settings including Addr, Registry, FlushInterval, DurationUnit, Prefix, and Percentiles","Config with TCPAddr and metrics.Registry exports metrics to Graphite via Once","Once returns an error when connecting to an unreachable address"],"goal":"verify github.com/cyberdelia/go-metrics-graphite.Config in pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432","kind":"HOW","packages":["pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432"],"schemaVersion":1,"symbols":["github.com/cyberdelia/go-metrics-graphite.Config"]},"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/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432"],"schemaVersion":1,"subject":"pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432","symbols":["github.com/cyberdelia/go-metrics-graphite.Config"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	github.com/cyberdelia/go-metrics-graphite v0.0.0-20161219230853-39f87cc3b432 // indirect
	github.com/rcrowley/go-metrics v0.0.0-20250401214520-65e299d6c5c9 // indirect
)

github.com/cyberdelia/go-metrics-graphite v0.0.0-20161219230853-39f87cc3b432 h1:M5QgkYacWj0Xs8MhpIK/5uwU02icXpEoSo9sM2aRCps=
github.com/cyberdelia/go-metrics-graphite v0.0.0-20161219230853-39f87cc3b432/go.mod h1:xwIwAxMvYnVrGJPe2FKx5prTrnAjGOD8zvDOnxnrrkM=
github.com/rcrowley/go-metrics v0.0.0-20250401214520-65e299d6c5c9 h1:bsUq1dX0N8AOIL7EB/X911+m4EHsnWEHeJ0c+3TTBrg=
github.com/rcrowley/go-metrics v0.0.0-20250401214520-65e299d6c5c9/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=

package sample

import (
	"net"
	"time"

	graphite "github.com/cyberdelia/go-metrics-graphite"
	"github.com/rcrowley/go-metrics"
)

// NewConfig initializes a graphite.Config with provided and default settings.
func NewConfig(addr *net.TCPAddr, registry metrics.Registry, prefix string) graphite.Config {
	return graphite.Config{
		Addr:          addr,
		Registry:      registry,
		FlushInterval: 10 * time.Millisecond,
		DurationUnit:  time.Millisecond,
		Prefix:        prefix,
		Percentiles:   []float64{0.5, 0.75, 0.95, 0.99},
	}
}

// FlushMetrics performs a single export flush using graphite.Once.
func FlushMetrics(c graphite.Config) error {
	return graphite.Once(c)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/cyberdelia/go-metrics-graphite.Config in pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/cyberdelia/go-metrics-graphite@v0.0.0-20161219230853-39f87cc3b432"
  ],
  "symbols": [
    "github.com/cyberdelia/go-metrics-graphite.Config"
  ]
}

package main

import (
	"bufio"
	"fmt"
	"net"
	"os"
	"strings"
	"sync"
	"time"

	_ "github.com/cyberdelia/go-metrics-graphite"
	"github.com/rcrowley/go-metrics"
	"sample"
)

func main() {
	// 1. Verify Config fields initialization
	dummyAddr, err := net.ResolveTCPAddr("tcp", "127.0.0.1:2003")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to resolve dummy addr: %v\n", err)
		os.Exit(1)
	}
	r := metrics.NewRegistry()
	cfg := sample.NewConfig(dummyAddr, r, "app.metrics")

	if cfg.Addr != dummyAddr {
		fmt.Fprintf(os.Stderr, "FAIL: Config.Addr mismatch\n")
		os.Exit(1)
	}
	if cfg.Registry != r {
		fmt.Fprintf(os.Stderr, "FAIL: Config.Registry mismatch\n")
		os.Exit(1)
	}
	if cfg.FlushInterval != 10*time.Millisecond {
		fmt.Fprintf(os.Stderr, "FAIL: Config.FlushInterval mismatch\n")
		os.Exit(1)
	}
	if cfg.DurationUnit != time.Millisecond {
		fmt.Fprintf(os.Stderr, "FAIL: Config.DurationUnit mismatch\n")
		os.Exit(1)
	}
	if cfg.Prefix != "app.metrics" {
		fmt.Fprintf(os.Stderr, "FAIL: Config.Prefix mismatch: got %q\n", cfg.Prefix)
		os.Exit(1)
	}
	if len(cfg.Percentiles) != 4 || cfg.Percentiles[0] != 0.5 || cfg.Percentiles[3] != 0.99 {
		fmt.Fprintf(os.Stderr, "FAIL: Config.Percentiles mismatch\n")
		os.Exit(1)
	}

	// 2. Verify metrics flush over TCP via Once
	ln, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to start listener: %v\n", err)
		os.Exit(1)
	}
	defer ln.Close()

	var receivedLines []string
	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		defer wg.Done()
		conn, err := ln.Accept()
		if err != nil {
			return
		}
		defer conn.Close()

		scanner := bufio.NewScanner(conn)
		for scanner.Scan() {
			receivedLines = append(receivedLines, scanner.Text())
		}
	}()

	counter := metrics.NewCounter()
	r.Register("requests.total", counter)
	counter.Inc(42)

	gauge := metrics.NewGauge()
	r.Register("memory.usage", gauge)
	gauge.Update(1024)

	liveCfg := sample.NewConfig(ln.Addr().(*net.TCPAddr), r, "testservice")

	if err := sample.FlushMetrics(liveCfg); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: FlushMetrics failed: %v\n", err)
		os.Exit(1)
	}

	ln.Close()
	wg.Wait()

	foundCounter := false
	foundGauge := false
	for _, line := range receivedLines {
		if strings.HasPrefix(line, "testservice.requests.total.count 42 ") {
			foundCounter = true
		}
		if strings.HasPrefix(line, "testservice.memory.usage.value 1024 ") {
			foundGauge = true
		}
	}

	if !foundCounter {
		fmt.Fprintf(os.Stderr, "FAIL: expected counter metric in lines, got: %v\n", receivedLines)
		os.Exit(1)
	}
	if !foundGauge {
		fmt.Fprintf(os.Stderr, "FAIL: expected gauge metric in lines, got: %v\n", receivedLines)
		os.Exit(1)
	}

	// 3. Verify Once returns error on unreachable address
	closedLn, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: could not allocate port: %v\n", err)
		os.Exit(1)
	}
	closedAddr := closedLn.Addr().(*net.TCPAddr)
	closedLn.Close()

	errCfg := sample.NewConfig(closedAddr, r, "errtest")
	if err := sample.FlushMetrics(errCfg); err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error when flushing to closed address, got nil\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all Config contract assertions passed")
}