fix: /vitals and /services report unavailable data instead of failing

systemgate/main.py

@@ -149,7 +149,10 @@ def vitals():
     # container's own filesystem and saying so is the difference between
     # telemetry and a misleading number.
     disk_path = os.environ.get("SYSTEMGATE_DISK_PATH", "/")
-    disk = psutil.disk_usage(disk_path)
+    try:
+        disk = psutil.disk_usage(disk_path)
+    except OSError:
+        disk = None
 
     # Read from psutil itself rather than from the environment, so this reports
     # where the numbers came from instead of where they were asked to come from.
@@ -167,7 +170,8 @@ def vitals():
         "cpu_percent": psutil.cpu_percent(interval=0.05),
         "cpu_count": psutil.cpu_count(),
         "memory": psutil.virtual_memory()._asdict(),
-        "disk": disk._asdict(),
+        # null when the disk path cannot be read; source.disk_path says which path.
+        "disk": disk._asdict() if disk is not None else None,
         "load": os.getloadavg() if hasattr(os, "getloadavg") else [0.0, 0.0, 0.0],
         "temps": temps,
         "source": {
@@ -214,7 +218,13 @@ def services(limit: int = 80):
     try:
         connections = psutil.net_connections(kind="inet")
     except (psutil.AccessDenied, OSError):
-        connections = []
+        return {
+            "status": "unavailable",
+            "results": [],
+            "source": "psutil.net_connections",
+            "metadata_only": True,
+            "errors": ["service_enumeration_unavailable"],
+        }
     for conn in connections:
         if str(getattr(conn, "status", "") or "") != "LISTEN":
             continue

tests/test_endpoints.py

@@ -123,6 +123,22 @@ def test_vitals_with_mocked_psutil(tmp_path, monkeypatch):
         assert data["memory"]["total"] == 100
 
 
+def test_vitals_survive_an_unreadable_disk_path(tmp_path, monkeypatch):
+    import systemgate.main as main
+
+    monkeypatch.setenv("SYSTEMGATE_DISK_PATH", str(tmp_path / "missing"))
+    monkeypatch.setattr(main.psutil, "sensors_temperatures", lambda fahrenheit=False: {}, raising=False)
+
+    with make_client(tmp_path, monkeypatch) as client:
+        response = client.get("/vitals", headers=headers())
+
+    assert response.status_code == 200
+    data = response.json()
+    assert data["disk"] is None
+    assert data["source"]["disk_path"] == str(tmp_path / "missing")
+    assert data["memory"]["total"] > 0
+
+
 def test_containers_truthfully_reports_unavailable(tmp_path, monkeypatch):
     with make_client(tmp_path, monkeypatch) as client:
         data = client.get("/containers", headers=headers()).json()

tests/test_inventory_limits.py

@@ -212,6 +212,8 @@ def test_services_survive_a_denied_connection_listing(tmp_path, monkeypatch):
     assert response.status_code == 200
     assert data["results"] == []
     assert data["metadata_only"] is True
+    assert data["status"] == "unavailable"
+    assert data["errors"] == ["service_enumeration_unavailable"]
 
 
 def test_processes_sort_skip_and_clamp(tmp_path, monkeypatch):