Keep make test under 2 GB of memory (closes #344)

Every test that starts a database hashed the bootstrap admin password
with Argon2id at 64 MB, which under -race holds about 150 MB per hash,
across dozens of parallel tests. The test packages that hash now lower
the memory cost to 1 MB from TestMain. One test still hashes and
verifies at the shipped parameters, which are unchanged.

script/test also runs at most four packages and eight parallel tests
at once: unbounded, a many-core host linked and ran every test binary
together.

Model: opus-5-5

.dockerignore

@@ -3,8 +3,10 @@
 # stage of the Dockerfile.
 .git/
 bin/
-# Extracted from 3p/ by `make assets` inside the build; a host copy is not
+# Third-party browser assets are fetched and hash-verified inside the build by
-# needed. The tarball in 3p/ must stay in the context.
+# script/fetch-assets. Excluding any host copy keeps a developer's working tree
+# from supplying the bytes that get shipped. The script and its
+# static/vendor.sha256 manifest stay in the context.
 static/js/alpine.min.js
 *.md
 LICENSE

.gitignore

@@ -46,6 +46,7 @@ temp/
 # CI cache barrier, written into the build context by the check workflow
 .ci-fingerprint
 
-# Alpine.js, extracted by `make assets` from its tarball in 3p/, which is
+# Third-party browser assets, fetched and hash-verified by
-# what is committed.
+# script/fetch-assets against static/vendor.sha256. Not committed:
-/static/js/alpine.min.js
+# REPO_POLICIES.md forbids minified bundles in version control.
+/static/js/alpine.min.js 

Dockerfile

@@ -51,8 +51,15 @@ RUN go mod download
 # the lint stage above.
 COPY . .
 
-# Run tests and build. Both first run script/assets, which extracts Alpine.js
+# Fetch the third-party browser assets the UI serves. They are not committed
-# from its tarball in 3p/.
+# (REPO_POLICIES.md forbids minified bundles in version control) and
+# .dockerignore keeps any host copy out of the build context, so this step is
+# the only way they enter the image. Each download is checked against a
+# hardcoded sha256 and the build fails on mismatch; make test re-checks the
+# hashes against the bytes go:embed actually put in the binary.
+RUN script/fetch-assets
+
+# Run tests and build
 RUN make test
 
 # Version stamped into the binary. .dockerignore excludes .git/, so
@@ -60,8 +67,8 @@ RUN make test
 # host and passes it in. The default is what a bare `docker build .`
 # with no --build-arg gets, and it names no tag the tree may not be at.
 #
-# Declared here, below the test step, so a changed version does not
+# Declared here, below the test and asset steps, so a changed version
-# invalidate its cached layer.
+# does not invalidate their cached layers.
 ARG VERSION=unknown
 
 RUN make build VERSION="$VERSION"

Makefile

@@ -28,7 +28,7 @@ setup:
 	@script/setup
 
 assets:
-	@script/assets
+	@script/fetch-assets
 
 test:
 	@script/test
@@ -45,13 +45,13 @@ fmt-check:
 check:
 	@script/check
 
-build: assets
+build:
 	go build -ldflags '$(strip -X main.version=$(VERSION) $(GO_LDFLAGS))' -o bin/webhooker ./cmd/webhooker
 
 run: build
 	./bin/webhooker
 
-dev: assets
+dev:
 	go run ./cmd/webhooker
 
 deps:

README.md

@@ -21,6 +21,9 @@ before deploying one.
 - Go 1.26.1+ (the version in `go.mod`)
 - Docker (for linting, for the test stage of the CI gate, and for
   containerized deployment)
+- `curl`, used by `script/fetch-assets` to download the third-party
+  browser assets, which are not committed (`make bootstrap` installs
+  it if missing)
 
 golangci-lint is not a prerequisite and must not be installed on the
 host: `script/bootstrap` does not install it, and `make lint` runs the
@@ -33,7 +36,9 @@ digest-pinned linter image via `Dockerfile.lint`.
 git clone https://git.eeqj.de/sneak/webhooker.git
 cd webhooker
 
-# Install the Go toolchain if missing, and the Go dependencies
+# Install Go dependencies and the third-party browser assets.
+# `make deps` alone is not enough: it only runs go mod download/tidy,
+# and the checks below need the fetched assets.
 make bootstrap
 
 # Run all checks (test, lint, format check)
@@ -53,7 +58,7 @@ make docker
 ```bash
 make bootstrap  # Install all dependencies (idempotent)
 make setup      # Bootstrap + install git pre-commit hook
-make assets     # Extract Alpine.js from 3p/ (test, check, build, dev run it)
+make assets     # Fetch + verify third-party browser assets
 make fmt        # Format code (gofmt + goimports)
 make fmt-check  # Fail if gofmt would change anything (writes nothing)
 make lint       # Run golangci-lint in Docker (Dockerfile.lint)
@@ -1216,15 +1221,14 @@ This repository adheres to the
 standard: normalized scripts in `script/` are the entrypoints for the
 development workflow. Ten of the Makefile's seventeen targets are thin
 shims that call them; `build`, `run`, `dev`, `deps`, `clean`, `css` and
-`version` are inline commands with no script behind them, though `build`,
+`version` are inline commands with no script behind them, though
-`run` and `dev` first run `script/assets`, and `build` and `version` both
+`build` and `version` both take their value from `script/version`.
-take their value from `script/version`.
 
-`script/test`, `make build` and `make dev` each run `script/assets`
+`make check` needs the third-party browser assets in `static/`, which
-first, which writes the ignored `static/js/alpine.min.js` (see
+are not committed, so run `make bootstrap` (or just `make assets`) once
-[Third-party browser assets](#third-party-browser-assets)), so
+after cloning. Without them the tests fail with a message naming that
-`make test`, `make check` and the pre-commit hook work on a fresh clone
+remedy. `make check` does not fetch them itself because it must not
-without a separate step.
+change any files in the repo.
 
 We provide:
 
@@ -1232,8 +1236,8 @@ We provide:
 - `script/setup` — make a fresh clone ready for development
   (bootstrap, then install-precommit)
 - `script/projectname` — output the project name ("webhooker")
-- `script/assets` — extract Alpine.js from its tarball in `3p/` (see
+- `script/fetch-assets` — download the third-party browser assets into
-  [Third-party browser assets](#third-party-browser-assets))
+  `static/`, verifying each against its pinned sha256
 - `script/test` — run the test suite
 - `script/lint` — run golangci-lint in Docker (see Linting below)
 - `script/fmt` — format all code (writes)
@@ -1255,25 +1259,24 @@ We provide:
 
 ## Third-party browser assets
 
-The web UI serves one third-party script, Alpine.js. Its npm package tarball
+The web UI serves one third-party script, Alpine.js. It is **not** committed:
-is committed as `3p/alpinejs-3.14.9.tgz`, byte for byte as the npm registry
+a minified bundle in the tree is unreviewable, and `REPO_POLICIES.md` bars
-publishes it. It is a dependency, not this repo's build output, so
+both committed build artifacts and unpinned external references.
-`REPO_POLICIES.md`'s rule against committed build artifacts does not apply.
-The directory is `3p/` rather than `vendor/` because Go treats a root
-`vendor/` directory as its module vendor directory.
 
-`script/assets` (`make assets`) extracts the browser build,
+Instead `script/fetch-assets` downloads it from a pinned URL, checks the
-`package/dist/cdn.min.js`, from the tarball to `static/js/alpine.min.js`,
+download against a hardcoded sha256, and installs it under `static/`. The
-where `go:embed` picks it up. `script/test`, `make build` and `make dev` run
+sha256 of every installed asset is recorded in `static/vendor.sha256`, and
-it first, and the Dockerfile builds through `make test` and `make build`, so
+`static/vendor_test.go` re-hashes the bytes `go:embed` put in the binary
-nothing downloads Alpine.js. The extracted file is not committed, and
+against that manifest — so the pin is enforced on what actually ships, not
-`.dockerignore` keeps any host copy out of the build context.
+merely written down. Any mismatch fails the build.
 
-To move to a new version: download
+`make bootstrap` runs the fetch for local development, and the Dockerfile
-`https://registry.npmjs.org/alpinejs/-/alpinejs-<version>.tgz`, check it
+runs it in the build stage; `.gitignore` and `.dockerignore` keep the
-against the `dist.integrity` hash listed at
+artifact out of both the repo and the build context.
-`https://registry.npmjs.org/alpinejs/<version>`, replace the tarball in `3p/`
+
-with it, update its file name in `script/assets`, and run `make check`.
+To move to a new version: update the version, URL, and tarball sha256 in
+`script/fetch-assets` and the asset sha256 in `static/vendor.sha256`, then
+run `make assets && make check`.
 
 ## Rationale
 
@@ -2752,8 +2755,6 @@ imports. The entry point is `cmd/webhooker/main.go`.
 
 ```
 webhooker/
-├── 3p/
-│   └── alpinejs-3.14.9.tgz    # Alpine.js npm package, extracted by make assets
 ├── cmd/webhooker/
 │   └── main.go               # Entry point: subcommand dispatch; no args locks DATA_DIR and wires fx
 ├── internal/
@@ -2847,7 +2848,8 @@ webhooker/
 │   ├── css/tailwind.css       # Generated stylesheet the pages load
 │   ├── css/style.css          # Older hand-written stylesheet, no longer loaded
 │   ├── js/app.js              # Progressive-enhancement copy-to-clipboard
-│   └── js/alpine.min.js       # Alpine.js, extracted from 3p/ by make assets, not committed
+│   ├── js/alpine.min.js       # Alpine.js, fetched by script/fetch-assets, not committed
+│   └── vendor.sha256          # Pinned hashes the fetched assets are verified against
 ├── templates/                 # Go HTML templates (base, login, sources, etc.)
 ├── script/                    # Scripts to Rule Them All entrypoints
 ├── Dockerfile                 # Three stages: lint, test+build, Alpine runtime
@@ -3159,14 +3161,14 @@ version is fixed independently of the compiler's:
    `make fmt-check`, then `golangci-lint config verify` and
    `golangci-lint run`, both with `--network=none`.
 2. **Builder stage** (`golang:1.26.1-bookworm`) — depends on the lint
-   stage passing (it copies a file from it), runs `make test` and
+   stage passing (it copies a file from it), runs `script/fetch-assets`
-   `make build` (both extract Alpine.js from `3p/` first), and finally
+   to download and verify the third-party browser assets, then runs
-   rebuilds the binary with `CGO_ENABLED=1` and static linking so it
+   `make test` and `make build`, and finally rebuilds the binary with
-   runs on musl. Both builds go through `make build`, the relink adding
+   `CGO_ENABLED=1` and static linking so it runs on musl. Both builds
-   its `-extldflags` via `GO_LDFLAGS`, so neither can drop the `-X` that
+   go through `make build`, the relink adding its `-extldflags` via
-   stamps the version. The version arrives as the `VERSION` build arg,
+   `GO_LDFLAGS`, so neither can drop the `-X` that stamps the version.
-   since the context has no `.git` (see
+   The version arrives as the `VERSION` build arg, since the context
-   [Version stamping](#version-stamping)).
+   has no `.git` (see [Version stamping](#version-stamping)).
 3. **Runtime stage** (`alpine:3.21`) — copies the static binary and
    `deploy/docker-entrypoint.sh`, creates the `/var/lib/webhooker`
    directory for all SQLite databases, exposes port 8080, and includes

cmd/webhooker/main.go

@@ -16,7 +16,6 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
-	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/resetpw"
 	"sneak.berlin/go/webhooker/internal/server"
@@ -178,10 +177,6 @@ func newApp() *fx.App {
 			healthcheck.New,
 			session.New,
 			handlers.New,
-			// The registry /metrics serves, and the delivery
-			// collectors registered on it.
-			metrics.NewRegistry,
-			metrics.New,
 			middleware.New,
 			// The one SSRF guard both target-creation validation
 			// and the delivery dialer consult, so they cannot

internal/database/export_test.go

@@ -79,3 +79,9 @@ func (d *Database) ExportSetBannerOut(w io.Writer) {
 func DummyPasswordHashForTest() string {
 	return dummyPasswordHash()
 }
+
+// HashPasswordWithDefaultsForTest hashes with the shipped Argon2id
+// parameters, which TestMain has lowered for HashPassword itself.
+func HashPasswordWithDefaultsForTest(password string) (string, error) {
+	return hashPasswordWith(password, DefaultPasswordConfig())
+}

internal/database/main_test.go

@@ -0,0 +1,14 @@
+package database_test
+
+import (
+	"testing"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestMain lowers the password hashing cost before any test runs. See
+// database.LowerPasswordHashCostForTest.
+func TestMain(m *testing.M) {
+	database.LowerPasswordHashCostForTest()
+	m.Run()
+}

internal/database/password.go

@@ -63,10 +63,24 @@ func DefaultPasswordConfig() *PasswordConfig {
 	}
 }
 
+// hashConfig is what HashPassword hashes with: the defaults above.
+// Only a test binary changes it, through LowerPasswordHashCostForTest,
+// before any test runs.
+//
+//nolint:gochecknoglobals // see above
+var hashConfig = DefaultPasswordConfig()
+
 // HashPassword generates an Argon2id hash of the password
 func HashPassword(password string) (string, error) {
-	config := DefaultPasswordConfig()
+	return hashPasswordWith(password, hashConfig)
+}
 
+// hashPasswordWith generates an Argon2id hash of the password with
+// the given parameters.
+func hashPasswordWith(
+	password string,
+	config *PasswordConfig,
+) (string, error) {
 	// Generate a salt
 	salt := make([]byte, config.SaltLen)
 

internal/database/password_test.go

@@ -192,6 +192,36 @@ func TestHashPasswordUniqueness(t *testing.T) {
 	}
 }
 
+// TestHashPassword_ShippedParameters hashes and verifies at the
+// shipped Argon2id parameters. Every other test hashes at the lowered
+// memory cost TestMain sets, so this is the one that keeps production
+// hashing covered. One hash and one verification: each costs 64 MB.
+func TestHashPassword_ShippedParameters(t *testing.T) {
+	t.Parallel()
+
+	password := "correct horse battery staple"
+
+	hash, err := database.HashPasswordWithDefaultsForTest(password)
+	if err != nil {
+		t.Fatalf("hashing with the shipped parameters: %v", err)
+	}
+
+	const shipped = "$argon2id$v=19$m=65536,t=1,p=4$"
+
+	if !strings.HasPrefix(hash, shipped) {
+		t.Errorf("hash = %q, want prefix %q", hash, shipped)
+	}
+
+	valid, err := database.VerifyPassword(password, hash)
+	if err != nil {
+		t.Fatalf("VerifyPassword() error = %v", err)
+	}
+
+	if !valid {
+		t.Error("VerifyPassword() returned false for correct password")
+	}
+}
+
 // TestVerifyDummyPassword_DoesRealWork covers the anti-enumeration
 // path. Login charges an unknown username a verification against a
 // dummy hash so that a nonexistent account is not answered in

internal/database/testing.go

@@ -45,3 +45,20 @@ func NewTestWebhookDBManagerWithLogger(
 		log:     log,
 	}
 }
+
+// testArgon2Memory is the Argon2id memory cost, in KiB, that test
+// binaries hash with: 1 MB instead of the shipped 64 MB.
+const testArgon2Memory = 1024
+
+// LowerPasswordHashCostForTest makes HashPassword use a 1 MB Argon2id
+// memory cost instead of the shipped 64 MB, for the rest of the
+// process. Call it from TestMain, before any test runs.
+//
+// Every test that starts a database hashes the bootstrap admin
+// password, and a package runs dozens of those tests in parallel.
+// Under the race detector each 64 MB hash holds about 150 MB resident.
+// VerifyPassword reads the cost from the hash it checks, so
+// verification follows. Production code never calls this.
+func LowerPasswordHashCostForTest() {
+	hashConfig.Memory = testArgon2Memory
+}

internal/delivery/engine.go

@@ -148,7 +148,6 @@ type EngineParams struct {
 	DBManager *database.WebhookDBManager
 	Logger    *logger.Logger
 	SSRFGuard *Guard
-	Metrics   *metrics.Set
 }
 
 // Engine processes queued deliveries in the background
@@ -168,10 +167,10 @@ type Engine struct {
 	retryCh    chan Task
 	workers    int
 
-	// mtr is the delivery metric set. Production wires the one
+	// mtr is the delivery metric set. Production wires the
-	// registered on the registry /metrics serves; a test can
+	// process-wide one; a test can substitute a set registered on
-	// substitute a set registered on a registry it holds, so it can
+	// a private registry so its assertions are not disturbed by
-	// gather what its own deliveries recorded.
+	// deliveries other tests are making at the same time.
 	mtr *metrics.Set
 
 	// targets maps each target type to its implementation.
@@ -205,7 +204,7 @@ func New(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    defaultWorkers,
-		mtr:        params.Metrics,
+		mtr:        metrics.Default(),
 	}
 
 	e.initTargets(&http.Client{

internal/delivery/export_test.go

@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
 	"gorm.io/gorm"
 	"sneak.berlin/go/webhooker/internal/database"
@@ -390,7 +389,7 @@ func NewTestEngine(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
-		mtr:        metrics.New(prometheus.NewRegistry()),
+		mtr:        metrics.Default(),
 	}
 	e.initTargets(client)
 
@@ -405,7 +404,7 @@ func NewTestEngineSmallRetry(
 	e := &Engine{
 		log:     log,
 		retryCh: make(chan Task, 1),
-		mtr:     metrics.New(prometheus.NewRegistry()),
+		mtr:     metrics.Default(),
 	}
 	e.initTargets(nil)
 
@@ -428,7 +427,7 @@ func NewTestEngineWithDB(
 		deliveryCh: make(chan Task, deliveryChannelSize),
 		retryCh:    make(chan Task, retryChannelSize),
 		workers:    workers,
-		mtr:        metrics.New(prometheus.NewRegistry()),
+		mtr:        metrics.Default(),
 	}
 	e.initTargets(client)
 
@@ -436,7 +435,8 @@ func NewTestEngineWithDB(
 }
 
 // ExportSetMetrics substitutes the engine's metric set, so a test can
-// assert on collectors registered on a registry it holds.
+// assert on collectors registered on a private registry instead of
+// the process-wide ones every other test is also moving.
 func (e *Engine) ExportSetMetrics(mtr *metrics.Set) {
 	e.mtr = mtr
 }

internal/delivery/metrics_test.go

@@ -35,8 +35,9 @@ const (
 )
 
 // mIsolate gives the setup's engine a metric set registered on a
-// registry this test holds, so its exact assertions can gather from
+// private registry. The process-wide collectors are moved by every
-// it.
+// other delivery test running in parallel, so exact assertions are
+// only possible against a registry this test owns.
 func mIsolate(
 	t *testing.T, s iSetup,
 ) *prometheus.Registry {

internal/gormlog/main_test.go

@@ -0,0 +1,14 @@
+package gormlog_test
+
+import (
+	"testing"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestMain lowers the password hashing cost before any test runs. See
+// database.LowerPasswordHashCostForTest.
+func TestMain(m *testing.M) {
+	database.LowerPasswordHashCostForTest()
+	m.Run()
+}

internal/handlers/handlers.go

@@ -12,7 +12,6 @@ import (
 	"net/http"
 	"sync/atomic"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/database"
 	"sneak.berlin/go/webhooker/internal/delivery"
@@ -62,8 +61,6 @@ type HandlersParams struct {
 	Notifier     delivery.Notifier
 	Evictor      delivery.WebhookEvictor
 	SSRFGuard    *delivery.Guard
-	Metrics      *metrics.Set
-	Registry     *prometheus.Registry
 }
 
 // Handlers provides HTTP handler methods for all application
@@ -125,7 +122,7 @@ func New(
 	s.mw = params.Middleware
 	s.notifier = params.Notifier
 	s.evictor = params.Evictor
-	s.mtr = params.Metrics
+	s.mtr = metrics.Default()
 	s.ssrf = params.SSRFGuard
 
 	// Parse all page templates once at startup

internal/handlers/handlers_test.go

@@ -20,7 +20,6 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
-	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/session"
 )
@@ -110,8 +109,6 @@ func newTestApp(
 			func(r *recordingEvictor) delivery.WebhookEvictor {
 				return r
 			},
-			metrics.NewRegistry,
-			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,

internal/handlers/main_test.go

@@ -0,0 +1,14 @@
+package handlers_test
+
+import (
+	"testing"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestMain lowers the password hashing cost before any test runs. See
+// database.LowerPasswordHashCostForTest.
+func TestMain(m *testing.M) {
+	database.LowerPasswordHashCostForTest()
+	m.Run()
+}

internal/handlers/metrics.go

@@ -1,21 +0,0 @@
-package handlers
-
-import (
-	"net/http"
-
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-)
-
-// HandleMetrics returns the Prometheus scrape handler for the
-// registry built by metrics.NewRegistry, which the HTTP, delivery, Go
-// runtime and process collectors register on. It is what
-// promhttp.Handler builds for the global default registry, including
-// the promhttp_metric_handler_* series that count scrapes, pointed at
-// that registry instead.
-func (s *Handlers) HandleMetrics() http.HandlerFunc {
-	reg := s.params.Registry
-
-	return promhttp.InstrumentMetricHandler(
-		reg, promhttp.HandlerFor(reg, promhttp.HandlerOpts{}),
-	).ServeHTTP
-}

internal/metrics/metrics.go

@@ -3,18 +3,17 @@
 // deliveries are attempted, how they end, how long they take, how
 // deep the queues are, and how many circuit breakers are open.
 //
-// It also builds the registry the authenticated /metrics route
+// The inbound HTTP metrics come from the go-http-metrics recorder in
-// serves. In production, these collectors, the inbound HTTP metrics
+// internal/middleware and land on prometheus.DefaultRegisterer. These
-// recorded in internal/middleware, and the Go runtime and process
+// collectors register there too, so both surfaces are gathered by the
-// collectors all register on that one registry, never on Prometheus's
+// one promhttp handler mounted on the authenticated /metrics route.
-// global default.
 package metrics
 
 import (
+	"sync"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"sneak.berlin/go/webhooker/internal/database"
 )
@@ -58,31 +57,25 @@ var knownTargetTypes = []database.TargetType{
 	database.TargetTypeSlack,
 }
 
-// NewRegistry returns the registry /metrics serves, carrying the Go
+// defaultSet is the process-wide metric set, registered on the same
-// runtime and process collectors that Prometheus's global default
+// registry the HTTP middleware and the /metrics handler already use.
-// registry carries, so the go_* and process_* series stay in the
+// It is built on first use rather than in an init so that a test
-// scrape.
+// binary that never touches metrics never registers them.
 //
-// A registry of its own, rather than the global default, is what lets
+//nolint:gochecknoglobals // one process-wide registration, by design
-// two dependency graphs in one process — two tests, say — each
+var defaultSet = sync.OnceValue(func() *Set {
-// register their collectors without the second registration
+	return New(prometheus.DefaultRegisterer)
-// panicking.
+})
-func NewRegistry() *prometheus.Registry {
-	reg := prometheus.NewRegistry()
-	reg.MustRegister(
-		collectors.NewGoCollector(),
-		collectors.NewProcessCollector(
-			collectors.ProcessCollectorOpts{},
-		),
-	)
 
-	return reg
+// Default returns the process-wide metric set.
+func Default() *Set {
+	return defaultSet()
 }
 
 // Set is one registered group of webhooker's delivery collectors.
-// Production builds one on the registry /metrics serves; tests build
+// Production uses the single Default set; tests build their own
-// their own against a private registry so assertions are not
+// against a private registry so assertions are not disturbed by
-// disturbed by deliveries other tests are making concurrently.
+// deliveries other tests are making concurrently.
 type Set struct {
 	eventsReceived      prometheus.Counter
 	deliveryAttempts    *prometheus.CounterVec
@@ -100,7 +93,7 @@ type Set struct {
 // New registers a full set of delivery collectors on reg and returns
 // it. It panics if reg already holds them, which is the intended
 // behaviour for a duplicate registration.
-func New(reg *prometheus.Registry) *Set {
+func New(reg prometheus.Registerer) *Set {
 	factory := promauto.With(reg)
 
 	s := &Set{

internal/middleware/export_test.go

@@ -10,7 +10,8 @@ import (
 
 // MetricsMiddlewareForTest builds the metrics recording middleware
 // against a caller-supplied recorder, so a test can gather from its
-// own Prometheus registry without building a whole Middleware.
+// own Prometheus registry rather than the process-wide default one
+// that Middleware.Metrics uses.
 func MetricsMiddlewareForTest(
 	rec httpmetrics.Recorder,
 ) func(http.Handler) http.Handler {

internal/middleware/metrics.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/go-chi/chi"
 	httpmetrics "github.com/slok/go-http-metrics/metrics"
+	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	ghmm "github.com/slok/go-http-metrics/middleware"
 	"github.com/slok/go-http-metrics/middleware/std"
 )
@@ -150,17 +151,17 @@ func (r boundedLabelRecorder) AddInflightRequests(
 
 var _ httpmetrics.Recorder = boundedLabelRecorder{}
 
-// Metrics returns middleware that records Prometheus HTTP metrics
+// Metrics returns middleware that records Prometheus HTTP metrics on
-// with the Middleware's one recorder, which New builds on the registry
+// the default registry, which is the one the /metrics route gathers.
-// the /metrics route serves and NewForTest on a registry of its own.
-// Every call reuses that recorder, so any number of routers can
-// install it.
 func (s *Middleware) Metrics() func(http.Handler) http.Handler {
-	return metricsMiddleware(s.metricsRecorder)
+	return metricsMiddleware(
+		prommetrics.NewRecorder(prommetrics.Config{}),
+	)
 }
 
 // metricsMiddleware builds the recording middleware against a given
-// recorder, so tests can gather from a registry of their own.
+// recorder, so tests can gather from a registry of their own instead
+// of the process-wide default.
 func metricsMiddleware(
 	rec httpmetrics.Recorder,
 ) func(http.Handler) http.Handler {

internal/middleware/metrics_test.go

@@ -57,8 +57,9 @@ const (
 // Server.setupWebhookRoutes inside it. That ordering is the whole
 // defect, so a test that flattens it would prove nothing.
 //
-// The recorder writes to a registry of the test's own, so each test
+// The recorder writes to a registry of the test's own rather than the
-// observes only its own traffic.
+// process-wide default one, so each test observes only its own
+// traffic.
 func metricsTestRouter(
 	t *testing.T,
 	receiverLimit int,
@@ -454,29 +455,3 @@ func TestMetrics_StatusAndSizeStillRecorded(t *testing.T) {
 		"the interceptor must still count written bytes",
 	)
 }
-
-// TestMetrics_WorksOnNewForTestMiddleware pins that a Middleware built
-// by NewForTest has a recorder of its own: its Metrics() serves a
-// request instead of panicking, and a second one does not collide
-// with the first.
-func TestMetrics_WorksOnNewForTestMiddleware(t *testing.T) {
-	t.Parallel()
-
-	log := slog.New(slog.DiscardHandler)
-	cfg := &config.Config{Environment: "prod"}
-	ok := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
-		_, _ = w.Write([]byte(okBody))
-	})
-
-	for range 2 {
-		h := middleware.NewForTest(log, cfg, nil).Metrics()(ok)
-
-		req := httptest.NewRequestWithContext(
-			t.Context(), http.MethodGet, okRoute, nil,
-		)
-		w := httptest.NewRecorder()
-		h.ServeHTTP(w, req)
-
-		assert.Equal(t, http.StatusOK, w.Code)
-	}
-}

internal/middleware/middleware.go

@@ -13,9 +13,6 @@ import (
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
 	"github.com/go-chi/cors"
-	"github.com/prometheus/client_golang/prometheus"
-	httpmetrics "github.com/slok/go-http-metrics/metrics"
-	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"go.uber.org/fx"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/globals"
@@ -151,11 +148,10 @@ const (
 type MiddlewareParams struct {
 	fx.In
 
-	Logger   *logger.Logger
+	Logger  *logger.Logger
-	Globals  *globals.Globals
+	Globals *globals.Globals
-	Config   *config.Config
+	Config  *config.Config
-	Session  *session.Session
+	Session *session.Session
-	Registry *prometheus.Registry
 }
 
 // Middleware provides HTTP middleware for logging, CORS, auth, and
@@ -165,14 +161,6 @@ type Middleware struct {
 	params  *MiddlewareParams
 	session *session.Session
 
-	// metricsRecorder records the inbound HTTP metrics. New builds
-	// it on the registry /metrics serves, NewForTest on a registry
-	// of its own. Either way it is built once per Middleware and
-	// Metrics reuses it, because building it registers its
-	// collectors, and a second registration on the same registry
-	// panics.
-	metricsRecorder httpmetrics.Recorder
-
 	// loginGuard counts failed credential verifications and bounds
 	// concurrent password hashing. It is built on first use so that
 	// every construction path gets one; see guard().
@@ -191,9 +179,6 @@ func New(
 	s.params = &params
 	s.log = params.Logger.Get()
 	s.session = params.Session
-	s.metricsRecorder = prommetrics.NewRecorder(
-		prommetrics.Config{Registry: params.Registry},
-	)
 
 	return s, nil
 }

internal/middleware/testing.go

@@ -3,17 +3,12 @@ package middleware
 import (
 	"log/slog"
 
-	"github.com/prometheus/client_golang/prometheus"
-	prommetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/session"
 )
 
 // NewForTest creates a Middleware with the minimum dependencies
 // needed for testing. This bypasses the fx lifecycle.
-//
-// Its metrics recorder writes to a fresh registry of its own, so
-// Metrics() works on it and two of them never collide.
 func NewForTest(
 	log *slog.Logger,
 	cfg *config.Config,
@@ -25,8 +20,5 @@ func NewForTest(
 			Config: cfg,
 		},
 		session: sess,
-		metricsRecorder: prommetrics.NewRecorder(
-			prommetrics.Config{Registry: prometheus.NewRegistry()},
-		),
 	}
 }

internal/resetpw/main_test.go

@@ -0,0 +1,14 @@
+package resetpw_test
+
+import (
+	"testing"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestMain lowers the password hashing cost before any test runs. See
+// database.LowerPasswordHashCostForTest.
+func TestMain(m *testing.M) {
+	database.LowerPasswordHashCostForTest()
+	m.Run()
+}

internal/resetpw/resetpw_test.go

@@ -24,7 +24,6 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
-	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/resetpw"
 	"sneak.berlin/go/webhooker/internal/session"
@@ -141,7 +140,7 @@ func (n *noopEvictor) EvictWebhook(string) {}
 // and the database, exactly as internal/handlers builds them.
 //
 // One application per test function, not per case: every start that
-// finds no account seeds one at 64 MB of Argon2id, and this package's
+// finds no account seeds one with an Argon2id hash, and this package's
 // budget is not the place to spend that repeatedly.
 func newServerApp(
 	t *testing.T, dir string,
@@ -164,8 +163,6 @@ func newServerApp(
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
 			func() delivery.WebhookEvictor { return &noopEvictor{} },
-			metrics.NewRegistry,
-			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,

internal/server/main_test.go

@@ -0,0 +1,14 @@
+package server_test
+
+import (
+	"testing"
+
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestMain lowers the password hashing cost before any test runs. See
+// database.LowerPasswordHashCostForTest.
+func TestMain(m *testing.M) {
+	database.LowerPasswordHashCostForTest()
+	m.Run()
+}

internal/server/routes.go

@@ -7,6 +7,7 @@ import (
 	sentryhttp "github.com/getsentry/sentry-go/http"
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"sneak.berlin/go/webhooker/static"
 )
 
@@ -129,7 +130,12 @@ func (s *Server) setupRoutes() {
 	if s.params.Config.MetricsAuthEnabled() {
 		s.router.Group(func(r chi.Router) {
 			r.Use(s.mw.MetricsAuth())
-			r.Get("/metrics", s.h.HandleMetrics())
+			r.Get(
+				"/metrics",
+				http.HandlerFunc(
+					promhttp.Handler().ServeHTTP,
+				),
+			)
 		})
 	}
 

internal/server/routes_test.go

@@ -24,7 +24,6 @@ import (
 	"sneak.berlin/go/webhooker/internal/handlers"
 	"sneak.berlin/go/webhooker/internal/healthcheck"
 	"sneak.berlin/go/webhooker/internal/logger"
-	"sneak.berlin/go/webhooker/internal/metrics"
 	"sneak.berlin/go/webhooker/internal/middleware"
 	"sneak.berlin/go/webhooker/internal/server"
 	"sneak.berlin/go/webhooker/internal/session"
@@ -114,8 +113,6 @@ func newTestEnvWithConfig(
 			session.New,
 			func() delivery.Notifier { return &noopNotifier{} },
 			func() delivery.WebhookEvictor { return &noopEvictor{} },
-			metrics.NewRegistry,
-			metrics.New,
 			middleware.New,
 			delivery.NewGuard,
 			handlers.New,
@@ -1030,46 +1027,3 @@ func TestMetricsRouteUnmountedOnHalfSetConfig(t *testing.T) {
 		})
 	}
 }
-
-// TestTwoMetricsRoutersInOneProcess pins
-// https://git.eeqj.de/sneak/webhooker/issues/227: a second
-// metrics-enabled router in one process used to panic, because the
-// HTTP metrics registered on Prometheus's global default registry.
-// Two routers are built over separate dependency graphs and a third
-// over the first graph again, and each must still serve the HTTP,
-// delivery, Go runtime and process series, and the series counting
-// scrapes of /metrics itself.
-func TestTwoMetricsRoutersInOneProcess(t *testing.T) {
-	t.Parallel()
-
-	first := newTestEnvWithConfig(
-		t, metricsConfig(t, metricsUser, metricsAuthValue),
-	)
-	second := newTestEnvWithConfig(
-		t, metricsConfig(t, metricsUser, metricsAuthValue),
-	)
-	third := &testEnv{
-		router: server.NewRouterForTest(
-			first.log.Get(), first.cfg, first.mw, first.hnd,
-		),
-	}
-
-	for _, env := range []*testEnv{first, second, third} {
-		env.get("/", nil)
-
-		scrape := env.metricsRequest(metricsUser, metricsAuthValue)
-		require.Equal(t, http.StatusOK, scrape.Code)
-
-		for _, series := range []string{
-			"http_request_duration_seconds",
-			"http_response_size_bytes",
-			"http_requests_inflight",
-			"webhooker_events_received_total",
-			"go_goroutines",
-			"process_start_time_seconds",
-			"promhttp_metric_handler_requests_total",
-		} {
-			assert.Contains(t, scrape.Body.String(), series)
-		}
-	}
-}

internal/server/static_assets_test.go

@@ -13,9 +13,9 @@ import (
 
 // TestBaseTemplateScriptsAreServed walks every /s/ script the base
 // template loads on each page and fetches it through the real router.
-// Alpine.js is extracted from its tarball in 3p/ at build time, so the
+// Alpine.js is fetched at build time rather than committed, so nothing
-// file is not in the tree: this is the check that the page still gets
+// in the repo guarantees it is present: this is the check that the page
-// the JavaScript it asks for.
+// still gets the JavaScript it asks for.
 func TestBaseTemplateScriptsAreServed(t *testing.T) {
 	t.Parallel()
 

script/assets

@@ -1,16 +0,0 @@
-#!/bin/sh
-# script/assets: extract Alpine.js from its npm package tarball, committed
-# in 3p/, to static/js/alpine.min.js, where go:embed reads it. The
-# extracted file is not committed. script/test, make build and make dev run
-# this first.
-set -eu
-
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
-
-main() {
-    cd "$ROOT"
-    tar -xzOf 3p/alpinejs-3.14.9.tgz package/dist/cdn.min.js \
-        >static/js/alpine.min.js
-}
-
-main "$@"

script/bootstrap

@@ -4,7 +4,9 @@
 # installed tools are skipped. Base tooling comes from nix, apt, brew,
 # or apk (detected in that order); assumes NOTHING is present (not git,
 # make, or go). golangci-lint is deliberately not installed: linting runs
-# only in docker, via script/lint and Dockerfile.lint.
+# only in docker, via script/lint and Dockerfile.lint. Finishes by running
+# script/fetch-assets, which installs the hash-pinned third-party browser
+# assets the repo does not commit.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
@@ -67,6 +69,11 @@ main() {
 
     go mod download
 
+    # Third-party browser assets are not committed; fetch and verify them
+    # so a fresh clone can build and test.
+    if missing curl; then pkg_install curl curl curl curl; fi
+    "$ROOT/script/fetch-assets"
+
     echo "bootstrap complete"
 }
 

script/check

@@ -1,7 +1,6 @@
 #!/bin/sh
 # script/check: run all checks (test, lint, fmt-check). Our own
-# extension to scripts-to-rule-them-all.
+# extension to scripts-to-rule-them-all. Must not modify any files.
-# Writes only the ignored static/js/alpine.min.js, through script/test.
 # Generic: usually needs no adaptation.
 set -eu
 

script/fetch-assets

@@ -0,0 +1,104 @@
+#!/bin/sh
+# script/fetch-assets: download the third-party browser assets the web UI
+# ships and install them under static/. Minified bundles are not committed
+# (REPO_POLICIES.md: no build artifacts in version control), so the build
+# fetches them here. Every download is verified against a hardcoded sha256
+# before it is installed, and any mismatch aborts. Idempotent: an asset
+# already present with its pinned hash is left alone.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+# The sha256 of each installed asset lives in static/vendor.sha256, in
+# sha256sum(1) format, with paths relative to static/. That file is the
+# single source of truth: this script verifies against it, and
+# static/vendor_test.go asserts the bytes embedded into the binary match
+# it, so the hash cannot rot into a value nothing checks.
+MANIFEST="static/vendor.sha256"
+
+# Alpine.js 3.14.9, 2026-08-17. Fetched from registry.npmjs.org, the
+# publisher of record; the jsDelivr and unpkg copies are mirrors of this
+# same tarball. dist/cdn.min.js is the browser build Alpine publishes for
+# a <script> tag.
+ALPINE_VERSION="3.14.9"
+ALPINE_URL="https://registry.npmjs.org/alpinejs/-/alpinejs-${ALPINE_VERSION}.tgz"
+# sha256 of alpinejs-3.14.9.tgz
+ALPINE_TARBALL_SHA256="97dad7c0c81e659cfc8e7700055da9770f8186187cb9a8a76efb57e00d5ce52a"
+ALPINE_MEMBER="package/dist/cdn.min.js"
+ALPINE_DEST="js/alpine.min.js"
+
+sha256_of() {
+    if command -v sha256sum >/dev/null 2>&1; then
+        sha256sum "$1" | cut -d' ' -f1
+    else
+        shasum -a 256 "$1" | cut -d' ' -f1
+    fi
+}
+
+# expected_sha256 <path-relative-to-static>
+expected_sha256() {
+    awk -v want="$1" '$2 == want { print $1; found = 1 }
+        END { if (!found) exit 1 }' "$ROOT/$MANIFEST"
+}
+
+# verify <file> <expected-sha256> <what>
+verify() {
+    actual="$(sha256_of "$1")"
+    if [ "$actual" != "$2" ]; then
+        echo "fetch-assets: sha256 mismatch for $3" >&2
+        echo "  expected: $2" >&2
+        echo "  actual:   $actual" >&2
+        exit 1
+    fi
+}
+
+# up_to_date <path-relative-to-static> <expected-sha256>
+up_to_date() {
+    [ -f "$ROOT/static/$1" ] || return 1
+    [ "$(sha256_of "$ROOT/static/$1")" = "$2" ]
+}
+
+fetch_alpine() {
+    want="$(expected_sha256 "$ALPINE_DEST")"
+
+    if up_to_date "$ALPINE_DEST" "$want"; then
+        echo "fetch-assets: static/$ALPINE_DEST already at $want"
+        return 0
+    fi
+
+    echo "fetch-assets: fetching Alpine.js $ALPINE_VERSION from $ALPINE_URL"
+    tmp="$(mktemp -d)"
+    trap 'rm -rf "$tmp"' EXIT INT TERM
+    curl -fsSL -o "$tmp/alpine.tgz" "$ALPINE_URL"
+    verify "$tmp/alpine.tgz" "$ALPINE_TARBALL_SHA256" "alpinejs-${ALPINE_VERSION}.tgz"
+    tar -xzOf "$tmp/alpine.tgz" "$ALPINE_MEMBER" >"$tmp/alpine.min.js"
+    verify "$tmp/alpine.min.js" "$want" "$ALPINE_MEMBER from alpinejs-${ALPINE_VERSION}.tgz"
+
+    mkdir -p "$(dirname "$ROOT/static/$ALPINE_DEST")"
+    cp "$tmp/alpine.min.js" "$ROOT/static/$ALPINE_DEST"
+    rm -rf "$tmp"
+    trap - EXIT INT TERM
+    echo "fetch-assets: installed static/$ALPINE_DEST ($want)"
+}
+
+# Re-check every manifest entry against what is now on disk, so an entry
+# no script installs fails loudly instead of passing silently.
+verify_manifest() {
+    while read -r want path; do
+        case "$want" in '' | '#'*) continue ;; esac
+        if [ ! -f "$ROOT/static/$path" ]; then
+            echo "fetch-assets: $MANIFEST lists static/$path, which is missing" >&2
+            exit 1
+        fi
+        verify "$ROOT/static/$path" "$want" "static/$path"
+    done <"$ROOT/$MANIFEST"
+}
+
+main() {
+    cd "$ROOT"
+    fetch_alpine
+    verify_manifest
+    echo "fetch-assets: all assets in $MANIFEST verified"
+}
+
+main "$@"

script/test

@@ -22,14 +22,18 @@
 # The one figure above 90s is GOMAXPROCS 1, a synthetic core floor rather than
 # a condition CI runs under. If a CPU-limited runner ever puts a real run near
 # 67s, that is the datum to revisit the org figure with.
+#
+# -p 4 -parallel 8 keep the run under 2 GB of memory: at most four test
+# binaries build or run at once, each with at most eight parallel tests. Under
+# -race every test binary and every link costs a few hundred MB, so the
+# defaults (one per core) add up to several GB on a many-core host.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    "$ROOT/script/assets"
+    go test -v -race -p 4 -parallel 8 -timeout 90s ./...
-    go test -v -race -timeout 90s ./...
 }
 
 main "$@"

static/vendor.sha256

@@ -0,0 +1 @@
+3ed1eed252488921df65e363d6715deb04d7f92aaedb9e52199fdf73cb1e0ad3  js/alpine.min.js

static/vendor_test.go

@@ -0,0 +1,92 @@
+package static_test
+
+import (
+	"bufio"
+	"crypto/sha256"
+	"encoding/hex"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"sneak.berlin/go/webhooker/static"
+)
+
+const manifestPath = "vendor.sha256"
+
+// fetchHint is appended to every failure here: the assets the manifest
+// covers are fetched by the build, not committed, so a fresh clone that
+// has not run script/fetch-assets fails this test and should be told why.
+const fetchHint = "run `script/fetch-assets` (or `make assets`) to install " +
+	"the pinned third-party assets"
+
+// TestVendoredAssetsMatchManifest asserts that every asset listed in
+// static/vendor.sha256 is embedded in the binary with exactly the pinned
+// bytes. script/fetch-assets verifies the same hashes at download time;
+// this test verifies them again on what actually ships, so a build that
+// skipped, cached, or subverted the fetch cannot produce a binary serving
+// unpinned third-party JavaScript.
+func TestVendoredAssetsMatchManifest(t *testing.T) {
+	t.Parallel()
+
+	entries := readManifest(t)
+	require.NotEmpty(t, entries, "%s lists no assets", manifestPath)
+
+	for path, want := range entries {
+		t.Run(path, func(t *testing.T) {
+			t.Parallel()
+
+			data, err := static.Static.ReadFile(path)
+			require.NoErrorf(
+				t, err,
+				"%s is listed in %s but is not embedded; %s",
+				path, manifestPath, fetchHint,
+			)
+
+			sum := sha256.Sum256(data)
+			got := hex.EncodeToString(sum[:])
+			require.Equalf(
+				t, want, got,
+				"embedded %s does not match its pinned sha256 in %s; %s",
+				path, manifestPath, fetchHint,
+			)
+		})
+	}
+}
+
+// readManifest parses static/vendor.sha256, which is in sha256sum(1)
+// format with paths relative to static/.
+func readManifest(t *testing.T) map[string]string {
+	t.Helper()
+
+	f, err := os.Open(manifestPath)
+	require.NoError(t, err, "opening %s", manifestPath)
+
+	defer func() { require.NoError(t, f.Close()) }()
+
+	entries := make(map[string]string)
+	scanner := bufio.NewScanner(f)
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		fields := strings.Fields(line)
+		require.Lenf(
+			t, fields, 2,
+			"%s: malformed entry %q, want \"<sha256>  <path>\"",
+			manifestPath, line,
+		)
+
+		sum, path := fields[0], fields[1]
+		require.Lenf(t, sum, 64, "%s: %q is not a sha256", manifestPath, sum)
+		entries[path] = sum
+	}
+
+	require.NoError(t, scanner.Err(), "reading %s", manifestPath)
+
+	return entries
+}