Harden lab status refresh

backend/atlas_portal/routes/lab.py

@@ -14,6 +14,15 @@ from .. import settings
 _LAB_STATUS_CACHE: dict[str, Any] = {"ts": 0.0, "value": None}
 
 
+def _status_response(payload: dict[str, Any]) -> Any:
+    """Return lab status JSON with browser and proxy caching disabled."""
+
+    response = jsonify(payload)
+    response.headers["Cache-Control"] = "no-store, max-age=0"
+    response.headers["Pragma"] = "no-cache"
+    return response
+
+
 def _vm_query(expr: str) -> float | None:
     """Run one instant VictoriaMetrics query and return the largest value."""
 
@@ -171,7 +180,7 @@ def register(app) -> None:
         now = time.time()
         cached = _LAB_STATUS_CACHE.get("value")
         if cached and (now - float(_LAB_STATUS_CACHE.get("ts", 0.0)) < settings.LAB_STATUS_CACHE_SEC):
-            return jsonify(cached)
+            return _status_response(cached)
 
         t_total = time.perf_counter()
         timings_ms: dict[str, int] = {}
@@ -242,4 +251,4 @@ def register(app) -> None:
 
         _LAB_STATUS_CACHE["ts"] = now
         _LAB_STATUS_CACHE["value"] = payload
-        return jsonify(payload)
+        return _status_response(payload)

backend/tests/test_lab_routes.py

@@ -129,6 +129,8 @@ def test_lab_status_uses_cache_and_probe_fallbacks(monkeypatch) -> None:
     payload = response.get_json()
 
     assert response.status_code == 200
+    assert response.headers["Cache-Control"] == "no-store, max-age=0"
+    assert response.headers["Pragma"] == "no-cache"
     assert payload["connected"] is True
     assert payload["atlas"]["source"] == "grafana"
     assert payload["dedicated_hosts"]["up"] is True
@@ -144,6 +146,7 @@ def test_lab_status_uses_cache_and_probe_fallbacks(monkeypatch) -> None:
 
     second = client.get("/api/lab/status")
     assert second.get_json() == payload
+    assert second.headers["Cache-Control"] == "no-store, max-age=0"
 
     lab._LAB_STATUS_CACHE["ts"] = 0.0
     lab._LAB_STATUS_CACHE["value"] = None

frontend/src/App.vue

@@ -37,7 +37,8 @@ async function refreshLabStatus() {
   const controller = new AbortController();
   const timeoutId = window.setTimeout(() => controller.abort(), 10000);
   try {
-    const resp = await fetch("/api/lab/status", {
+    const resp = await fetch(`/api/lab/status?ts=${Date.now()}`, {
+      cache: "no-store",
       headers: { Accept: "application/json" },
       signal: controller.signal,
     });
@@ -45,11 +46,13 @@ async function refreshLabStatus() {
     labStatus.value = await resp.json();
     statusError.value = "";
   } catch (err) {
-    labStatus.value = null;
-    if (err?.name === "AbortError") {
-      statusError.value = "Live data timed out";
-    } else {
-      statusError.value = "Live data unavailable";
+    if (!labStatus.value) {
+      labStatus.value = null;
+      if (err?.name === "AbortError") {
+        statusError.value = "Live data timed out";
+      } else {
+        statusError.value = "Live data unavailable";
+      }
     }
   } finally {
     window.clearTimeout(timeoutId);
@@ -69,7 +72,7 @@ onUnmounted(() => {
 
 function scheduleNextPoll() {
   if (pollTimerId) window.clearTimeout(pollTimerId);
-  const delayMs = labStatus.value ? 30000 : 8000;
+  const delayMs = labStatus.value ? 30000 : 4000;
   pollTimerId = window.setTimeout(refreshLabStatus, delayMs);
 }
 </script>

testing/frontend/e2e/home.spec.js

@@ -49,7 +49,7 @@ test.beforeEach(async ({ page }) => {
       body: JSON.stringify({ enabled: true, reset_url: "https://sso.example.dev/reset" }),
     });
   });
-  await page.route("**/api/lab/status", async (route) => {
+  await page.route("**/api/lab/status*", async (route) => {
     await route.fulfill({
       status: 200,
       contentType: "application/json",
@@ -106,7 +106,7 @@ test("keeps the homepage usable when public status fails", async ({ page }) => {
   await page.addInitScript(() => {
     window.__LAB_STATUS_FAIL__ = true;
   });
-  await page.route("**/api/lab/status", async (route) => {
+  await page.route("**/api/lab/status*", async (route) => {
     await route.fulfill({
       status: 503,
       contentType: "application/json",

testing/frontend/e2e/request-access.spec.js

@@ -8,7 +8,7 @@ test.beforeEach(async ({ page }) => {
       body: JSON.stringify({ enabled: false }),
     });
   });
-  await page.route("**/api/lab/status", async (route) => {
+  await page.route("**/api/lab/status*", async (route) => {
     await route.fulfill({
       status: 200,
       contentType: "application/json",

testing/frontend/unit/static-views.spec.js

@@ -215,6 +215,13 @@ describe("static shell views and components", () => {
     });
     await flushPromises();
     expect(app.text()).toContain("true");
+    expect(global.fetch).toHaveBeenCalledWith(
+      expect.stringMatching(/^\/api\/lab\/status\?ts=\d+$/),
+      expect.objectContaining({
+        cache: "no-store",
+        headers: { Accept: "application/json" },
+      }),
+    );
 
     await app.unmount();