github.com/caddyserver/certmagic v0.23.0: NewCache

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/caddyserver/certmagic.NewCache in pkg:golang/github.com/caddyserver/certmagic@v0.23.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/caddyserver/certmagic@v0.23.0
Demonstrate these symbols/APIs:
  - github.com/caddyserver/certmagic.NewCache

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.

package sample

import (
	"time"

	"github.com/caddyserver/certmagic"
	"go.uber.org/zap"
)

// NewCustomCache creates and returns a new certmagic.Cache with custom options.
func NewCustomCache(capacity int, renewInterval time.Duration, logger *zap.Logger) *certmagic.Cache {
	if logger == nil {
		logger = zap.NewNop()
	}

	var cache *certmagic.Cache
	cache = certmagic.NewCache(certmagic.CacheOptions{
		GetConfigForCert: func(cert certmagic.Certificate) (*certmagic.Config, error) {
			return certmagic.New(cache, certmagic.Config{
				Logger: logger,
			}), nil
		},
		RenewCheckInterval: renewInterval,
		Capacity:           capacity,
		Logger:             logger,
	})

	return cache
}

{"case":{"caseId":"case:sha256:03ffef104e27699fdb5781fefd93c03e52de62042a55042889dd67dc227d657a","contract":["certmagic.NewCache panics if GetConfigForCert is not provided in CacheOptions","certmagic.NewCache returns a valid Cache instance when configured with GetConfigForCert","Cache.Stop cleanly releases resources and terminates background maintenance"],"goal":"verify github.com/caddyserver/certmagic.NewCache in pkg:golang/github.com/caddyserver/certmagic@v0.23.0","kind":"HOW","packages":["pkg:golang/github.com/caddyserver/certmagic@v0.23.0"],"schemaVersion":1,"symbols":["github.com/caddyserver/certmagic.NewCache"]},"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/caddyserver/certmagic@v0.23.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/caddyserver/certmagic@v0.23.0","symbols":["github.com/caddyserver/certmagic.NewCache"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	github.com/caddyserver/certmagic v0.23.0 // indirect
	github.com/caddyserver/zerossl v0.1.3 // indirect
	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
	github.com/libdns/libdns v1.0.0-beta.1 // indirect
	github.com/mholt/acmez/v3 v3.1.2 // indirect
	github.com/miekg/dns v1.1.63 // indirect
	github.com/zeebo/blake3 v0.2.4 // indirect
	go.uber.org/multierr v1.11.0 // indirect
	go.uber.org/zap v1.27.0 // indirect
	go.uber.org/zap/exp v0.3.0 // indirect
	golang.org/x/crypto v0.36.0 // indirect
	golang.org/x/mod v0.24.0 // indirect
	golang.org/x/net v0.37.0 // indirect
	golang.org/x/sync v0.12.0 // indirect
	golang.org/x/sys v0.31.0 // indirect
	golang.org/x/text v0.23.0 // indirect
	golang.org/x/tools v0.31.0 // indirect
)

github.com/caddyserver/certmagic v0.23.0 h1:CfpZ/50jMfG4+1J/u2LV6piJq4HOfO6ppOnOf7DkFEU=
github.com/caddyserver/certmagic v0.23.0/go.mod h1:9mEZIWqqWoI+Gf+4Trh04MOVPD0tGSxtqsxg87hAIH4=
github.com/caddyserver/zerossl v0.1.3 h1:onS+pxp3M8HnHpN5MMbOMyNjmTheJyWRaZYwn+YTAyA=
github.com/caddyserver/zerossl v0.1.3/go.mod h1:CxA0acn7oEGO6//4rtrRjYgEoa4MFw/XofZnrYwGqG4=
github.com/klauspost/cpuid/v2 v2.2.10 h1:tBs3QSyvjDyFTq3uoc/9xFpCuOsJQFNPiAhYdw2skhE=
github.com/klauspost/cpuid/v2 v2.2.10/go.mod h1:hqwkgyIinND0mEev00jJYCxPNVRVXFQeu1XKlok6oO0=
github.com/libdns/libdns v1.0.0-beta.1 h1:KIf4wLfsrEpXpZ3vmc/poM8zCATXT2klbdPe6hyOBjQ=
github.com/libdns/libdns v1.0.0-beta.1/go.mod h1:4Bj9+5CQiNMVGf87wjX4CY3HQJypUHRuLvlsfsZqLWQ=
github.com/mholt/acmez/v3 v3.1.2 h1:auob8J/0FhmdClQicvJvuDavgd5ezwLBfKuYmynhYzc=
github.com/mholt/acmez/v3 v3.1.2/go.mod h1:L1wOU06KKvq7tswuMDwKdcHeKpFFgkppZy/y0DFxagQ=
github.com/miekg/dns v1.1.63 h1:8M5aAw6OMZfFXTT7K5V0Eu5YiiL8l7nUAkyN6C9YwaY=
github.com/miekg/dns v1.1.63/go.mod h1:6NGHfjhpmr5lt3XPLuyfDJi5AXbNIPM9PY6H6sF1Nfs=
github.com/zeebo/blake3 v0.2.4 h1:KYQPkhpRtcqh0ssGYcKLG1JYvddkEA8QwCM/yBqhaZI=
github.com/zeebo/blake3 v0.2.4/go.mod h1:7eeQ6d2iXWRGF6npfaxl2CU+xy2Fjo2gxeyZGCRUjcE=
go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
go.uber.org/zap v1.27.0 h1:aJMhYGrd5QSmlpLMr2MftRKl7t8J8PTZPA732ud/XR8=
go.uber.org/zap v1.27.0/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=
go.uber.org/zap/exp v0.3.0 h1:6JYzdifzYkGmTdRR59oYH+Ng7k49H9qVpWwNSsGJj3U=
go.uber.org/zap/exp v0.3.0/go.mod h1:5I384qq7XGxYyByIhHm6jg5CHkGY0nsTfbDLgDDlgJQ=
golang.org/x/crypto v0.36.0 h1:AnAEvhDddvBdpY+uR+MyHmuZzzNqXSe/GvuDeob5L34=
golang.org/x/crypto v0.36.0/go.mod h1:Y4J0ReaxCR1IMaabaSMugxJES1EpwhBHhv2bDHklZvc=
golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww=
golang.org/x/net v0.37.0 h1:1zLorHbz+LYj7MQlSf1+2tPIIgibq2eL5xkrGk6f+2c=
golang.org/x/net v0.37.0/go.mod h1:ivrbrMbzFq5J41QOQh0siUuly180yBYtLp+CKbEaFx8=
golang.org/x/sync v0.12.0 h1:MHc5BpPuC30uJk597Ri8TV3CNZcTLu6B6z4lJy+g6Jw=
golang.org/x/sync v0.12.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
golang.org/x/text v0.23.0 h1:D71I7dUrlY+VX0gQShAThNGHFxZ13dGLBHQLVl1mJlY=
golang.org/x/text v0.23.0/go.mod h1:/BLNzu4aZCJ1+kcD0DNRotWKage4q2rGVAg4o22unh4=
golang.org/x/tools v0.31.0 h1:0EedkvKDbh+qistFTd0Bcwe/YLh4vHwWEkiI0toFIBU=
golang.org/x/tools v0.31.0/go.mod h1:naFTU+Cev749tSJRXJlna0T3WxKvb1kWEx15xA4SdmQ=

{
  "schemaVersion": 1,
  "goal": "verify github.com/caddyserver/certmagic.NewCache in pkg:golang/github.com/caddyserver/certmagic@v0.23.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/caddyserver/certmagic@v0.23.0"
  ],
  "symbols": [
    "github.com/caddyserver/certmagic.NewCache"
  ]
}

package main

import (
	"fmt"
	"os"
	"time"

	"sample"

	"github.com/caddyserver/certmagic"
	"go.uber.org/zap"
)

func main() {
	// Test 1: NewCache panics if GetConfigForCert is not set
	panicked := false
	func() {
		defer func() {
			if r := recover(); r != nil {
				panicked = true
			}
		}()
		certmagic.NewCache(certmagic.CacheOptions{})
	}()
	if !panicked {
		fmt.Fprintln(os.Stderr, "FAIL: expected certmagic.NewCache to panic when GetConfigForCert is nil")
		os.Exit(1)
	}
	fmt.Println("PASS: certmagic.NewCache panics when GetConfigForCert is nil")

	// Test 2: NewCache creates a valid Cache when GetConfigForCert is provided
	cache := sample.NewCustomCache(50, 5*time.Minute, zap.NewNop())
	if cache == nil {
		fmt.Fprintln(os.Stderr, "FAIL: expected non-nil Cache from NewCustomCache")
		os.Exit(1)
	}
	fmt.Println("PASS: certmagic.NewCache returns a valid Cache instance")

	// Test 3: Cache.Stop cleanly terminates maintenance
	cache.Stop()
	fmt.Println("PASS: Cache.Stop terminates successfully")

	fmt.Println("All contract tests passed.")
}