Add CPU usage to host inventory

agent/tests/test_agent.py

@@ -6,7 +6,7 @@ from pathlib import Path
 import tempfile
 import threading
 import unittest
-from unittest.mock import patch
+from unittest.mock import mock_open, patch
 
 spec = importlib.util.spec_from_file_location("ec_agent", Path(__file__).resolve().parents[1] / "ec_agent.py")
 module = importlib.util.module_from_spec(spec)
@@ -74,6 +74,39 @@ class AgentTests(unittest.TestCase):
         self.agent.journal.close()
         self.temp.cleanup()
 
+    def cpu_sample(self, line):
+        with patch.object(Path, "open", mock_open(read_data=line)):
+            return self.agent.cpu_usage_percent()
+
+    def test_cpu_usage_uses_interval_and_excludes_guest_double_counting(self):
+        self.assertIsNone(self.cpu_sample("cpu 100 0 50 800 50 0 0 0 20 0\n"))
+        # 30 busy ticks (including steal), 60 idle, 10 I/O wait = 30%.
+        self.assertEqual(self.cpu_sample("cpu 120 0 55 860 60 0 0 5 30 0\n"), 30.0)
+        self.assertEqual(self.cpu_sample("cpu 120 0 55 960 60 0 0 5 30 0\n"), 0.0)
+        self.assertEqual(self.cpu_sample("cpu 220 0 55 960 60 0 0 5 30 0\n"), 100.0)
+
+    def test_cpu_usage_rebases_after_reset_or_invalid_sample(self):
+        baseline = "cpu 100 0 50 800 50 0 0 0\n"
+        self.assertIsNone(self.cpu_sample(baseline))
+        self.assertIsNone(self.cpu_sample(baseline))
+        self.assertIsNone(self.cpu_sample("cpu 10 0 5 80 5 0 0 0\n"))
+        self.assertIsNone(self.cpu_sample("cpu 20 0 5 90 4 0 0 0\n"))
+        for invalid in ("", "cpu0 1 2 3 4 5 6 7 8", "cpu 1 2", "cpu x 0 0 0 0 0 0 0", "cpu -1 0 0 0 0 0 0 0"):
+            self.assertIsNone(self.cpu_sample(invalid))
+            self.assertIsNone(self.cpu_sample(baseline))
+        with patch.object(Path, "open", side_effect=OSError("unavailable")):
+            self.assertIsNone(self.agent.cpu_usage_percent())
+        self.assertIsNone(self.cpu_sample(baseline))
+
+    def test_inventory_reports_cpu_only_when_available(self):
+        for usage in (None, 0.0, 42.3, 100.0):
+            with patch.object(self.agent, "cpu_usage_percent", return_value=usage):
+                inventory = self.agent.inventory()
+            if usage is None:
+                self.assertNotIn("cpuUsagePercent", inventory)
+            else:
+                self.assertEqual(inventory["cpuUsagePercent"], usage)
+
     def operation(self, kind, payload=None, op_id="operation-1", generation=1):
         return {"id": op_id, "kind": kind, "instanceId": INSTANCE, "generation": generation, "payload": payload or {}}