API for out-of-band scale-to-zero pin

server/cmd/api/api/api.go

@@ -49,7 +49,7 @@ type ApiService struct {
 
 	// DevTools upstream manager (Chromium supervisord log tailer)
 	upstreamMgr *devtoolsproxy.UpstreamManager
-	stz         scaletozero.Controller
+	stz         scaletozero.PinnedController
 
 	// inputMu serializes input-related operations (mouse, keyboard, screenshot)
 	inputMu sync.Mutex
@@ -96,7 +96,7 @@ func New(
 	recordManager recorder.RecordManager,
 	factory recorder.FFmpegRecorderFactory,
 	upstreamMgr *devtoolsproxy.UpstreamManager,
-	stz scaletozero.Controller,
+	stz scaletozero.PinnedController,
 	nekoAuthClient *nekoclient.AuthClient,
 	captureSession *capturesession.CaptureSession,
 	eventStream    *events.EventStream,

server/cmd/api/api/scaletozero.go

@@ -0,0 +1,24 @@
+package api
+
+import (
+	"context"
+
+	"github.com/kernel/kernel-images/server/lib/logger"
+	oapi "github.com/kernel/kernel-images/server/lib/oapi"
+)
+
+func (s *ApiService) DisableScaleToZero(ctx context.Context, _ oapi.DisableScaleToZeroRequestObject) (oapi.DisableScaleToZeroResponseObject, error) {
+	if err := s.stz.Pin(ctx); err != nil {
+		logger.FromContext(ctx).Error("failed to disable scale-to-zero", "err", err)
+		return oapi.DisableScaleToZero500JSONResponse{InternalErrorJSONResponse: oapi.InternalErrorJSONResponse{Message: "failed to disable scale-to-zero"}}, nil
+	}
+	return oapi.DisableScaleToZero204Response{}, nil
+}
+
+func (s *ApiService) EnableScaleToZero(ctx context.Context, _ oapi.EnableScaleToZeroRequestObject) (oapi.EnableScaleToZeroResponseObject, error) {
+	if err := s.stz.Unpin(ctx); err != nil {
+		logger.FromContext(ctx).Error("failed to enable scale-to-zero", "err", err)
+		return oapi.EnableScaleToZero500JSONResponse{InternalErrorJSONResponse: oapi.InternalErrorJSONResponse{Message: "failed to enable scale-to-zero"}}, nil
+	}
+	return oapi.EnableScaleToZero204Response{}, nil
+}

server/e2e/e2e_scaletozero_test.go

@@ -0,0 +1,60 @@
+package e2e
+
+import (
+	"context"
+	"net/http"
+	"os/exec"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestScaleToZeroDisableEnable exercises POST /scaletozero/{disable,enable}
+// against the real built image. The unikraft control file does not exist
+// inside the docker test container, so the underlying scale-to-zero write is
+// a no-op — this test validates HTTP wiring, idempotency, and that the
+// scale-to-zero middleware coexists with the disable/enable handlers.
+func TestScaleToZeroDisableEnable(t *testing.T) {
+	t.Parallel()
+
+	if _, err := exec.LookPath("docker"); err != nil {
+		t.Skipf("docker not available: %v", err)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
+	defer cancel()
+
+	c := NewTestContainer(t, headlessImage)
+	require.NoError(t, c.Start(ctx, ContainerConfig{}), "failed to start container")
+	defer c.Stop(ctx)
+
+	require.NoError(t, c.WaitReady(ctx), "api not ready")
+
+	client, err := c.APIClient()
+	require.NoError(t, err, "failed to create API client")
+
+	// Idempotent disable.
+	r1, err := client.DisableScaleToZeroWithResponse(ctx)
+	require.NoError(t, err, "DisableScaleToZero request failed")
+	require.Equal(t, http.StatusNoContent, r1.StatusCode(), "unexpected status: %s body=%s", r1.Status(), string(r1.Body))
+
+	r2, err := client.DisableScaleToZeroWithResponse(ctx)
+	require.NoError(t, err, "second DisableScaleToZero request failed")
+	require.Equal(t, http.StatusNoContent, r2.StatusCode(), "unexpected status: %s body=%s", r2.Status(), string(r2.Body))
+
+	// Normal request must still flow while disabled (scaletozero middleware
+	// runs on every request — the pin must not deadlock or break it).
+	readResp, err := client.ReadClipboardWithResponse(ctx)
+	require.NoError(t, err, "ReadClipboard request failed while disabled")
+	require.Equal(t, http.StatusOK, readResp.StatusCode(), "unexpected read status while disabled: %s body=%s", readResp.Status(), string(readResp.Body))
+
+	// Idempotent enable.
+	r3, err := client.EnableScaleToZeroWithResponse(ctx)
+	require.NoError(t, err, "EnableScaleToZero request failed")
+	require.Equal(t, http.StatusNoContent, r3.StatusCode(), "unexpected status: %s body=%s", r3.Status(), string(r3.Body))
+
+	r4, err := client.EnableScaleToZeroWithResponse(ctx)
+	require.NoError(t, err, "second EnableScaleToZero request failed")
+	require.Equal(t, http.StatusNoContent, r4.StatusCode(), "unexpected status: %s body=%s", r4.Status(), string(r4.Body))
+}