build(makefile): fix lint-todo for golangci-lint v2

Applies what go fix now proposes, so make fmt is a no-op on a clean tree
instead of dirtying these two files on every run. Both rewrites are
equivalent: Cut's first result matches SplitN(s, sep, 2)[0], and SplitSeq
iterates the same substrings without building the intermediate slice.

Makefile

@@ -212,11 +212,22 @@ lint-prettier: ## Lint non-Golang codebase
 
 .PHONY: lint-todo
 lint-todo: ## Find TODOs in Golang codebase
-	golangci-lint run --no-config --disable-all --enable godox
+	golangci-lint run --no-config --default=none --enable godox
 
+# TODO: restore a plain "go fix ./..." once both modernizers stop rewriting this
+# codebase into code that does not compile. Re-check by dropping a flag and
+# running "make fmt && make lint". Removing an analyzer upstream makes go fix
+# fail with "flag provided but not defined", so this cannot rot silently.
+#   embedlit folds a post-literal field assignment into a literal that already
+#   sets that key, producing a duplicate field name (cmd/gotenberg.go). Fixed in
+#   Go 1.27.1, so drop that flag once the toolchain moves past 1.27.0.
+#   See https://github.com/golang/go/issues/81101.
+#   errorsastype rewrites errors.As to errors.AsType[T] without checking that T
+#   satisfies error, which breaks on api.HttpError since it does not embed
+#   error. Still broken as of Go 1.27.1.
 .PHONY: fmt
 fmt: ## Format Golang codebase and "optimize" the dependencies
-	go fix ./...
+	go fix -embedlit=false -errorsastype=false ./...
 	golangci-lint fmt
 	go mod tidy
 

pkg/gotenberg/supervisor.go

@@ -59,8 +59,9 @@ type ProcessSupervisor interface {
 	// Healthy checks and returns the health status of the managed [Process].
 	//
 	// A non-started process is considered healthy (startup is deferred until
-	// the first request). Returns false if the process is currently restarting
-	// or is reported unhealthy by the underlying [Process].
+	// the first request), as is one going through a planned restart, since it
+	// keeps serving traffic. Returns false during an unplanned restart or when
+	// the underlying [Process] reports unhealthy.
 	Healthy() bool
 
 	// Run executes a provided task while managing the state of the [Process].
@@ -103,6 +104,28 @@ const healthCheckCacheTTL = 2 * time.Second
 // this. See https://github.com/gotenberg/gotenberg/issues/1561.
 const healthFailureThreshold = 2
 
+// Restart reasons, also reported as the gotenberg.process.start.reason span
+// attribute by [processSupervisor.tracedLaunch]. Only
+// [restartReasonMaxRequests] is a planned restart: it fires on a healthy
+// process that reached its conversion limit, so the node keeps serving
+// traffic throughout. The others signal a process that cannot serve.
+const (
+	restartReasonFirstStart  = "first_start"
+	restartReasonUnhealthy   = "unhealthy"
+	restartReasonMaxRequests = "max_requests"
+)
+
+// defaultEagerRestartTimeout bounds the restart triggered after the maximum
+// request limit. That restart runs on a background context, unlike the one from
+// ensureHealthy which inherits the request deadline, so without a deadline of
+// its own the drain loop in [processSupervisor.doRestartLocked] would wait
+// forever on a task that never completes. That would pin isRestarting and,
+// with it, the health reported by [processSupervisor.Healthy]. Sized well above
+// --api-timeout (30s by default) plus the engine start timeouts (20s by
+// default) so it never fires while tasks are merely slow. The eager restart is
+// opportunistic: on expiry it aborts, and the next task retries it.
+const defaultEagerRestartTimeout = 2 * time.Minute
+
 type processSupervisor struct {
 	logger         *slog.Logger
 	engine         string
@@ -118,11 +141,16 @@ type processSupervisor struct {
 	// transient failure (such as a cold-start timeout) must not poison the
 	// supervisor for the rest of the container's lifetime. See
 	// https://github.com/gotenberg/gotenberg/issues/1538.
-	firstStartMu        sync.Mutex
-	reqCounter          atomic.Int64
-	reqQueueSize        atomic.Int64
-	restartsCounter     atomic.Int64
-	isRestarting        atomic.Bool
+	firstStartMu    sync.Mutex
+	reqCounter      atomic.Int64
+	reqQueueSize    atomic.Int64
+	restartsCounter atomic.Int64
+	isRestarting    atomic.Bool
+	// restartPlanned records whether the in-flight restart is a planned one
+	// (see [restartReasonMaxRequests]). Written before isRestarting and never
+	// cleared, so a reader that observed isRestarting always sees the matching
+	// kind. See [processSupervisor.Healthy].
+	restartPlanned      atomic.Bool
 	activeTasks         atomic.Int64
 	restartMutex        sync.Mutex
 	idleShutdownTimeout time.Duration
@@ -135,6 +163,9 @@ type processSupervisor struct {
 	consecutiveHealthFailures atomic.Int64  // reset to 0 on every successful probe
 	idleMu                    sync.Mutex    // protects idleStopChan
 	idleStopChan              chan struct{} // signal to stop the idle ticker goroutine
+	// eagerRestartTimeout bounds the restart from maybeRestartAfterTask.
+	// Defaults to [defaultEagerRestartTimeout]; only tests shorten it.
+	eagerRestartTimeout time.Duration
 }
 
 // NewProcessSupervisor initializes a new [ProcessSupervisor]. engine names the
@@ -158,6 +189,7 @@ func NewProcessSupervisor(logger *slog.Logger, engine string, process Process, m
 		maxQueueSize:        maxQueueSize,
 		maxConcurrency:      maxConcurrency,
 		idleShutdownTimeout: idleShutdownTimeout,
+		eagerRestartTimeout: defaultEagerRestartTimeout,
 	}
 	b.reqCounter.Store(0)
 	b.reqQueueSize.Store(0)
@@ -212,12 +244,18 @@ func (s *processSupervisor) restart() error {
 		s.logger.WarnContext(context.Background(), fmt.Sprintf("stop process before restart: %s", err))
 	}
 
+	// Reset the counter on the attempt, not on its outcome. Leaving it at the
+	// limit after a failed launch re-triggers maybeRestartAfterTask on every
+	// subsequent task, producing back-to-back restarts. Recovering a process
+	// that will not start is ensureHealthy's job: it restarts synchronously
+	// before running a task, and reports the failure to the caller.
+	s.reqCounter.Store(0)
+
 	err = s.Launch()
 	if err != nil {
 		return fmt.Errorf("restart process: %w", err)
 	}
 
-	s.reqCounter.Store(0)
 	s.restartsCounter.Add(1)
 	s.logger.DebugContext(context.Background(), "process successfully restarted")
 
@@ -234,9 +272,17 @@ func (s *processSupervisor) Healthy() bool {
 	}
 
 	if s.isRestarting.Load() {
-		// A restarting process is not yet healthy. This gives load balancers
-		// honest information so they can avoid routing traffic to this node.
-		return false
+		// A planned restart is routine maintenance: the process reached the
+		// limit set by --chromium-restart-after (env CHROMIUM_RESTART_AFTER) or
+		// --libreoffice-restart-after (env LIBREOFFICE_RESTART_AFTER) while
+		// healthy. Tasks arriving during it are requeued by acquireSlot, not
+		// rejected, so the node still serves traffic and must report healthy. A
+		// probe sent between two conversions used to fail here.
+		// See https://github.com/gotenberg/gotenberg/issues/1648.
+		//
+		// An unplanned restart keeps reporting unhealthy, which gives load
+		// balancers honest information so they can avoid routing traffic here.
+		return s.restartPlanned.Load()
 	}
 
 	// Cache hit: a recent probe succeeded. Skip the CDP roundtrip so probe
@@ -484,7 +530,7 @@ func (s *processSupervisor) ensureStarted(ctx context.Context) error {
 		return nil
 	}
 
-	err := s.tracedLaunch(ctx, "first_start", func() error {
+	err := s.tracedLaunch(ctx, restartReasonFirstStart, func() error {
 		return s.runWithDeadline(ctx, s.Launch)
 	})
 	if err != nil {
@@ -525,7 +571,7 @@ func (s *processSupervisor) ensureHealthy(ctx context.Context) error {
 
 	s.logger.DebugContext(context.Background(), "process is unhealthy, cannot handle task, restarting...")
 
-	if err := s.doRestart(ctx, "unhealthy"); err != nil {
+	if err := s.doRestart(ctx, restartReasonUnhealthy); err != nil {
 		return fmt.Errorf("process restart before task: %w", err)
 	}
 
@@ -533,9 +579,10 @@ func (s *processSupervisor) ensureHealthy(ctx context.Context) error {
 }
 
 // maybeRestartAfterTask checks if the maximum request limit has been reached
-// and, if so, triggers an asynchronous restart. If a restart is initiated, it
-// takes ownership of the caller's semaphore slot (the caller must not release
-// it). Returns true if ownership was taken.
+// and, if so, triggers an asynchronous restart bounded by
+// [defaultEagerRestartTimeout]. If a restart is initiated, it takes ownership
+// of the caller's semaphore slot (the caller must not release it). Returns true
+// if ownership was taken.
 func (s *processSupervisor) maybeRestartAfterTask(logger *slog.Logger) bool {
 	if s.maxReqLimit <= 0 || s.reqCounter.Load() < s.maxReqLimit {
 		return false
@@ -548,7 +595,10 @@ func (s *processSupervisor) maybeRestartAfterTask(logger *slog.Logger) bool {
 	s.logger.DebugContext(context.Background(), "max request limit reached, restarting eagerly...")
 
 	go func() {
-		restartErr := s.doRestartLocked(context.Background(), "max_requests")
+		ctx, cancel := context.WithTimeout(context.Background(), s.eagerRestartTimeout)
+		defer cancel()
+
+		restartErr := s.doRestartLocked(ctx, restartReasonMaxRequests)
 		s.restartMutex.Unlock()
 		if restartErr != nil {
 			s.logger.ErrorContext(context.Background(), fmt.Sprintf("process restart after task: %v", restartErr))
@@ -571,6 +621,10 @@ func (s *processSupervisor) doRestart(ctx context.Context, reason string) error
 
 // doRestartLocked performs the restart drain logic. The caller must hold restartMutex.
 func (s *processSupervisor) doRestartLocked(ctx context.Context, reason string) error {
+	// Publish the kind before raising the flag. [processSupervisor.Healthy]
+	// reads restartPlanned only after it observes isRestarting, so this
+	// ordering keeps it from pairing a new restart with a stale kind.
+	s.restartPlanned.Store(reason == restartReasonMaxRequests)
 	s.isRestarting.Store(true)
 	defer s.isRestarting.Store(false)
 

pkg/gotenberg/supervisor_test.go

@@ -160,13 +160,49 @@ func TestProcessSupervisor_restart(t *testing.T) {
 	}
 }
 
+// TestProcessSupervisor_restart_ResetsCounterOnFailedLaunch verifies that a
+// restart whose launch fails still clears the request counter. Leaving it at
+// the limit makes maybeRestartAfterTask re-fire on every subsequent task.
+func TestProcessSupervisor_restart_ResetsCounterOnFailedLaunch(t *testing.T) {
+	logger := slog.New(slog.DiscardHandler)
+
+	const maxReqLimit = 5
+
+	process := &ProcessMock{
+		StartMock:   func(_ *slog.Logger) error { return errors.New("start error") },
+		StopMock:    func(_ *slog.Logger) error { return nil },
+		HealthyMock: func(_ *slog.Logger) bool { return true },
+	}
+
+	ps := NewProcessSupervisor(logger, "test", process, maxReqLimit, 0, 1, 0).(*processSupervisor)
+	ps.reqCounter.Store(maxReqLimit)
+
+	err := ps.restart()
+	if err == nil {
+		t.Fatal("expected error but got none")
+	}
+
+	if got := ps.reqCounter.Load(); got != 0 {
+		t.Fatalf("expected the request counter to be reset but got %d", got)
+	}
+
+	if got := ps.restartsCounter.Load(); got != 0 {
+		t.Fatalf("expected the restarts counter to stay at 0 but got %d", got)
+	}
+
+	if ps.maybeRestartAfterTask(logger) {
+		t.Fatal("expected no further eager restart to be triggered")
+	}
+}
+
 func TestProcessSupervisor_Healthy(t *testing.T) {
 	for _, tc := range []struct {
-		scenario            string
-		initiallyStarted    bool
-		initiallyRestarting bool
-		processHealthy      bool
-		expectHealthy       bool
+		scenario                string
+		initiallyStarted        bool
+		initiallyRestarting     bool
+		initiallyRestartPlanned bool
+		processHealthy          bool
+		expectHealthy           bool
 	}{
 		{
 			scenario:         "non-started process is healthy",
@@ -179,6 +215,13 @@ func TestProcessSupervisor_Healthy(t *testing.T) {
 			initiallyRestarting: true,
 			expectHealthy:       false,
 		},
+		{
+			scenario:                "process going through a planned restart is healthy",
+			initiallyStarted:        true,
+			initiallyRestarting:     true,
+			initiallyRestartPlanned: true,
+			expectHealthy:           true,
+		},
 		{
 			scenario:         "process reports as healthy",
 			initiallyStarted: true,
@@ -208,6 +251,9 @@ func TestProcessSupervisor_Healthy(t *testing.T) {
 			if tc.initiallyRestarting {
 				ps.isRestarting.Store(true)
 			}
+			if tc.initiallyRestartPlanned {
+				ps.restartPlanned.Store(true)
+			}
 
 			healthy := ps.Healthy()
 
@@ -257,6 +303,204 @@ func TestProcessSupervisor_Healthy_ConsecutiveFailures(t *testing.T) {
 	}
 }
 
+// TestProcessSupervisor_Healthy_PlannedRestart reproduces
+// https://github.com/gotenberg/gotenberg/issues/1648. It drives the real
+// Run() path until the maximum request limit triggers the eager restart, then
+// asserts the supervisor reports healthy while that restart is in flight.
+// Tasks arriving during it are requeued by acquireSlot, not rejected, so the
+// node still serves traffic.
+func TestProcessSupervisor_Healthy_PlannedRestart(t *testing.T) {
+	logger := slog.New(slog.DiscardHandler)
+
+	const maxReqLimit = 10
+
+	restarting := make(chan struct{})
+	release := make(chan struct{})
+
+	var (
+		starts    atomic.Int64
+		signalOne sync.Once
+	)
+	process := &ProcessMock{
+		StartMock: func(_ *slog.Logger) error {
+			// Hold the restart open so the assertions below run inside the
+			// window that used to report unhealthy.
+			if starts.Add(1) > 1 {
+				signalOne.Do(func() { close(restarting) })
+				<-release
+			}
+
+			return nil
+		},
+		StopMock:    func(_ *slog.Logger) error { return nil },
+		HealthyMock: func(_ *slog.Logger) bool { return true },
+	}
+
+	ps := NewProcessSupervisor(logger, "test", process, maxReqLimit, 0, 1, 0).(*processSupervisor)
+
+	for i := range maxReqLimit {
+		err := ps.Run(context.Background(), logger, func() error { return nil })
+		if err != nil {
+			t.Fatalf("task %d: expected no error but got: %v", i+1, err)
+		}
+	}
+
+	select {
+	case <-restarting:
+	case <-time.After(10 * time.Second):
+		t.Fatalf("expected an eager restart after %d tasks", maxReqLimit)
+	}
+
+	if !ps.isRestarting.Load() {
+		t.Fatal("expected the supervisor to be restarting")
+	}
+
+	if !ps.restartPlanned.Load() {
+		t.Fatal("expected the restart to be flagged as planned")
+	}
+
+	if !ps.Healthy() {
+		t.Fatal("expected a planned restart to report healthy")
+	}
+
+	close(release)
+}
+
+// TestProcessSupervisor_Healthy_UnplannedRestart verifies the counterpart of
+// [TestProcessSupervisor_Healthy_PlannedRestart]: a restart triggered by an
+// unhealthy process keeps reporting unhealthy, so load balancers get honest
+// information.
+func TestProcessSupervisor_Healthy_UnplannedRestart(t *testing.T) {
+	logger := slog.New(slog.DiscardHandler)
+
+	restarting := make(chan struct{})
+	release := make(chan struct{})
+
+	var signalOne sync.Once
+	process := &ProcessMock{
+		StartMock: func(_ *slog.Logger) error {
+			signalOne.Do(func() { close(restarting) })
+			<-release
+
+			return nil
+		},
+		StopMock:    func(_ *slog.Logger) error { return nil },
+		HealthyMock: func(_ *slog.Logger) bool { return false },
+	}
+
+	ps := NewProcessSupervisor(logger, "test", process, 0, 0, 1, 0).(*processSupervisor)
+	ps.firstStart.Store(true)
+
+	go func() {
+		_ = ps.ensureHealthy(context.Background())
+	}()
+
+	select {
+	case <-restarting:
+	case <-time.After(10 * time.Second):
+		t.Fatal("expected an unhealthy restart to be triggered")
+	}
+
+	if !ps.isRestarting.Load() {
+		t.Fatal("expected the supervisor to be restarting")
+	}
+
+	if ps.restartPlanned.Load() {
+		t.Fatal("expected the restart not to be flagged as planned")
+	}
+
+	if ps.Healthy() {
+		t.Fatal("expected an unplanned restart to report unhealthy")
+	}
+
+	close(release)
+}
+
+// TestProcessSupervisor_doRestartLocked_DrainDeadline verifies that a drain
+// unable to acquire every slot gives up on the context deadline and clears
+// isRestarting. Without a deadline on the eager restart, a task that never
+// completes would pin the flag and, since a planned restart reports healthy,
+// leave the supervisor claiming health forever.
+func TestProcessSupervisor_doRestartLocked_DrainDeadline(t *testing.T) {
+	logger := slog.New(slog.DiscardHandler)
+
+	var starts atomic.Int64
+	process := &ProcessMock{
+		StartMock: func(_ *slog.Logger) error {
+			starts.Add(1)
+
+			return nil
+		},
+		StopMock:    func(_ *slog.Logger) error { return nil },
+		HealthyMock: func(_ *slog.Logger) bool { return true },
+	}
+
+	// A concurrency of 2 makes the drain acquire one slot on top of the one the
+	// triggering task hands over. Fill the semaphore so it never can, mimicking
+	// a concurrent task that never completes.
+	ps := NewProcessSupervisor(logger, "test", process, 1, 0, 2, 0).(*processSupervisor)
+	ps.semaphore <- struct{}{}
+	ps.semaphore <- struct{}{}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+
+	err := ps.doRestartLocked(ctx, restartReasonMaxRequests)
+	if err == nil {
+		t.Fatal("expected the drain to fail on the context deadline")
+	}
+
+	if ps.isRestarting.Load() {
+		t.Fatal("expected isRestarting to be cleared after a failed drain")
+	}
+
+	if starts.Load() != 0 {
+		t.Fatalf("expected no restart attempt after a failed drain but got %d", starts.Load())
+	}
+}
+
+// TestProcessSupervisor_maybeRestartAfterTask_Bounded verifies that the eager
+// restart runs under a deadline. A concurrent task that never completes blocks
+// the drain, and without a bound the restart goroutine would wait forever with
+// isRestarting pinned, leaving Healthy() reporting a planned restart for good.
+func TestProcessSupervisor_maybeRestartAfterTask_Bounded(t *testing.T) {
+	logger := slog.New(slog.DiscardHandler)
+
+	process := &ProcessMock{
+		StartMock:   func(_ *slog.Logger) error { return nil },
+		StopMock:    func(_ *slog.Logger) error { return nil },
+		HealthyMock: func(_ *slog.Logger) bool { return true },
+	}
+
+	ps := NewProcessSupervisor(logger, "test", process, 1, 0, 2, 0).(*processSupervisor)
+	ps.eagerRestartTimeout = 100 * time.Millisecond
+	ps.firstStart.Store(true)
+
+	// Wedge one slot so the drain, which needs one on top of the slot the
+	// triggering task hands over, can never complete.
+	ps.semaphore <- struct{}{}
+
+	err := ps.Run(context.Background(), logger, func() error { return nil })
+	if err != nil {
+		t.Fatalf("expected no error but got: %v", err)
+	}
+
+	waitFor := func(what string, want bool) {
+		t.Helper()
+
+		deadline := time.Now().Add(5 * time.Second)
+		for ps.isRestarting.Load() != want {
+			if time.Now().After(deadline) {
+				t.Fatalf("timed out waiting for the eager restart to %s", what)
+			}
+			time.Sleep(5 * time.Millisecond)
+		}
+	}
+
+	waitFor("start", true)
+	waitFor("give up on its deadline", false)
+}
+
 // TestProcessSupervisor_Healthy_CachesPositiveResult verifies that a
 // successful probe is cached for [healthCheckCacheTTL] so subsequent
 // supervisor.Healthy() calls do not re-issue the underlying process

pkg/modules/libreoffice/api/proxy_test.go

@@ -361,7 +361,7 @@ func TestSofficeProxyEnv_OverridesExisting(t *testing.T) {
 	// Old proxy values must be gone, not duplicated. Count exact-case keys.
 	counts := map[string]int{}
 	for _, kv := range out {
-		key := strings.SplitN(kv, "=", 2)[0]
+		key, _, _ := strings.Cut(kv, "=")
 		counts[key]++
 	}
 	for _, key := range []string{"http_proxy", "HTTP_PROXY", "https_proxy", "HTTPS_PROXY", "no_proxy", "NO_PROXY"} {

pkg/modules/pdfcpu/optimize.go

@@ -180,7 +180,7 @@ func (engine *PdfCpu) listImages(ctx context.Context, inputPath string) ([]pdfcp
 // their second column is not a numeric object number.
 func parseImagesList(output string) []pdfcpuImage {
 	var images []pdfcpuImage
-	for _, line := range strings.Split(output, "\n") {
+	for line := range strings.SplitSeq(output, "\n") {
 		cols := strings.Split(line, "│")
 		if len(cols) < 9 {
 			continue

test/integration/features/health.feature

@@ -1,6 +1,5 @@
 # TODO:
 # 1. Check if down for each module.
-# 2. Restarting modules do not make health check fail.
 
 @health
 Feature: /health
@@ -106,7 +105,19 @@ Feature: /health
     When I make a "HEAD" request to Gotenberg at the "/foo/health" endpoint
     Then the response status code should be 200
 
+  # A planned restart, the eager cycle after LIBREOFFICE_RESTART_AFTER
+  # conversions, must not fail the health check: requests arriving during it
+  # are requeued, not rejected. Setting the limit to 1 restarts LibreOffice
+  # after every conversion, so each probe lands right on a restart.
+  # See https://github.com/gotenberg/gotenberg/issues/1648.
+  Scenario: GET /health (Planned LibreOffice Restart)
+    Given I have a Gotenberg container with the following environment variable(s):
+      | LIBREOFFICE_RESTART_AFTER | 1 |
+    When I make 5 sequential "POST" requests to Gotenberg at the "/forms/libreoffice/convert" endpoint, probing "/health" after each, with the following form data and header(s):
+      | files | testdata/page_1.docx | file |
+    Then all sequential response status codes should be 200
+    Then all probe response status codes should be 200
+
 
 # TODO:
-# 1. Check if down for each module.
-# 2. Restarting modules do not make health check fail.
+# 1. Check if down for each module.

test/integration/scenario/scenario.go

@@ -88,6 +88,8 @@ func findScenarioLine(filePath, name string) int {
 type scenario struct {
 	resp                      *httptest.ResponseRecorder
 	concurrentResps           []*httptest.ResponseRecorder
+	probeResps                []*httptest.ResponseRecorder
+	sequentialResps           []*httptest.ResponseRecorder
 	workdir                   string
 	teststoreDir              string
 	gotenbergContainer        testcontainers.Container
@@ -99,6 +101,8 @@ type scenario struct {
 func (s *scenario) reset(ctx context.Context) error {
 	s.resp = httptest.NewRecorder()
 	s.concurrentResps = nil
+	s.probeResps = nil
+	s.sequentialResps = nil
 
 	err := os.RemoveAll(s.workdir)
 	if err != nil {
@@ -470,6 +474,130 @@ func (s *scenario) iMakeConcurrentRequestsToGotenberg(ctx context.Context, count
 	return nil
 }
 
+// iMakeSequentialRequestsToGotenbergProbing mirrors the client loop from
+// https://github.com/gotenberg/gotenberg/issues/1648: a conversion, then a
+// probe, repeated. It records both the conversion and the probe responses so a
+// scenario can assert that a planned process restart neither fails the probe
+// nor breaks the conversions. Requests are sequential on purpose, since the bug
+// only surfaces between two conversions.
+func (s *scenario) iMakeSequentialRequestsToGotenbergProbing(ctx context.Context, count int, method, endpoint, probeEndpoint string, dataTable *godog.Table) error {
+	if s.gotenbergContainer == nil {
+		return errors.New("no Gotenberg container")
+	}
+
+	fields := make(map[string][]string)
+	files := make(map[string][]string)
+	headers := make(map[string]string)
+
+	for _, row := range dataTable.Rows {
+		name := row.Cells[0].Value
+		value := row.Cells[1].Value
+		kind := row.Cells[2].Value
+
+		switch kind {
+		case "field":
+			fields[name] = append(fields[name], value)
+		case "file":
+			wd, err := os.Getwd()
+			if err != nil {
+				return fmt.Errorf("get current directory: %w", err)
+			}
+			value = fmt.Sprintf("%s/%s", wd, value)
+			files[name] = append(files[name], value)
+		case "header":
+			headers[name] = value
+		default:
+			return fmt.Errorf("unexpected %q %q", kind, value)
+		}
+	}
+
+	base, err := containerHttpEndpoint(ctx, s.gotenbergContainer, "3000")
+	if err != nil {
+		return fmt.Errorf("get container HTTP endpoint: %w", err)
+	}
+
+	record := func(resp *http.Response) (*httptest.ResponseRecorder, error) {
+		defer resp.Body.Close()
+
+		body, readErr := io.ReadAll(resp.Body)
+		if readErr != nil {
+			return nil, fmt.Errorf("read response body: %w", readErr)
+		}
+
+		rec := httptest.NewRecorder()
+		rec.Code = resp.StatusCode
+		for key, values := range resp.Header {
+			for _, v := range values {
+				rec.Header().Add(key, v)
+			}
+		}
+		_, writeErr := rec.Body.Write(body)
+		if writeErr != nil {
+			return nil, fmt.Errorf("write response body: %w", writeErr)
+		}
+
+		return rec, nil
+	}
+
+	s.probeResps = make([]*httptest.ResponseRecorder, 0, count)
+	s.sequentialResps = make([]*httptest.ResponseRecorder, 0, count)
+
+	for i := range count {
+		resp, reqErr := doFormDataRequest(method, fmt.Sprintf("%s%s", base, endpoint), fields, files, headers)
+		if reqErr != nil {
+			return fmt.Errorf("request %d: do request: %w", i+1, reqErr)
+		}
+
+		rec, recErr := record(resp)
+		if recErr != nil {
+			return fmt.Errorf("request %d: %w", i+1, recErr)
+		}
+		s.resp = rec
+		s.sequentialResps = append(s.sequentialResps, rec)
+
+		probeResp, probeErr := doRequest(http.MethodGet, fmt.Sprintf("%s%s", base, probeEndpoint), nil, nil)
+		if probeErr != nil {
+			return fmt.Errorf("probe %d: do request: %w", i+1, probeErr)
+		}
+
+		probeRec, probeRecErr := record(probeResp)
+		if probeRecErr != nil {
+			return fmt.Errorf("probe %d: %w", i+1, probeRecErr)
+		}
+		s.probeResps = append(s.probeResps, probeRec)
+	}
+
+	return nil
+}
+
+func (s *scenario) allProbeResponseStatusCodesShouldBe(expected int) error {
+	if len(s.probeResps) == 0 {
+		return errors.New("no probe responses recorded")
+	}
+
+	for i, resp := range s.probeResps {
+		if resp.Code != expected {
+			return fmt.Errorf("probe %d: expected status %d, got %d %q", i+1, expected, resp.Code, resp.Body.String())
+		}
+	}
+
+	return nil
+}
+
+func (s *scenario) allSequentialResponseStatusCodesShouldBe(expected int) error {
+	if len(s.sequentialResps) == 0 {
+		return errors.New("no sequential responses recorded")
+	}
+
+	for i, resp := range s.sequentialResps {
+		if resp.Code != expected {
+			return fmt.Errorf("sequential response %d: expected status %d, got %d %q", i+1, expected, resp.Code, resp.Body.String())
+		}
+	}
+
+	return nil
+}
+
 func (s *scenario) allConcurrentResponseStatusCodesShouldBe(expected int) error {
 	if len(s.concurrentResps) == 0 {
 		return errors.New("no concurrent responses recorded")
@@ -1644,10 +1772,13 @@ func InitializeScenario(ctx *godog.ScenarioContext) {
 	ctx.When(`^I make a "(GET|HEAD)" request to Gotenberg at the "([^"]*)" endpoint with the following header\(s\):$`, s.iMakeARequestToGotenbergWithTheFollowingHeaders)
 	ctx.When(`^I make a "(POST)" request to Gotenberg at the "([^"]*)" endpoint with the following form data and header\(s\):$`, s.iMakeARequestToGotenbergWithTheFollowingFormDataAndHeaders)
 	ctx.When(`^I make (\d+) concurrent "(POST)" requests to Gotenberg at the "([^"]*)" endpoint with the following form data and header\(s\):$`, s.iMakeConcurrentRequestsToGotenberg)
+	ctx.When(`^I make (\d+) sequential "(POST)" requests to Gotenberg at the "([^"]*)" endpoint, probing "([^"]*)" after each, with the following form data and header\(s\):$`, s.iMakeSequentialRequestsToGotenbergProbing)
 	ctx.When(`^I wait for the asynchronous request to the webhook$`, s.iWaitForTheAsynchronousRequestToWebhook)
 	ctx.Then(`^the Gotenberg container (should|should NOT) log the following entries:$`, s.theGotenbergContainerShouldLogTheFollowingEntries)
 	ctx.Then(`^the response status code should be (\d+)$`, s.theResponseStatusCodeShouldBe)
 	ctx.Then(`^all concurrent response status codes should be (\d+)$`, s.allConcurrentResponseStatusCodesShouldBe)
+	ctx.Then(`^all probe response status codes should be (\d+)$`, s.allProbeResponseStatusCodesShouldBe)
+	ctx.Then(`^all sequential response status codes should be (\d+)$`, s.allSequentialResponseStatusCodesShouldBe)
 	ctx.Then(`^all concurrent responses should have (\d+) PDF\(s\)$`, s.allConcurrentResponsesShouldHavePdfs)
 	ctx.Then(`^the (response|webhook request|file request|server request) header "([^"]*)" should be "([^"]*)"$`, s.theHeaderValueShouldBe)
 	ctx.Then(`^the webhook request header "([^"]*)" should carry trace id "([^"]*)"$`, s.theWebhookRequestHeaderShouldCarryTraceID)