[openstack-hypervisor] Add action list-gpus

Add action list-gpus to retrieve any GPUs
from openstack-hypervisor snap

Change-Id: I021547c1c951375bce3c6ecfbd7e1c2132e6f3cc
Signed-off-by: Hemanth Nakkina <hemanth.nakkina@canonical.com>

charms/openstack-hypervisor/charmcraft.yaml

@@ -164,6 +164,10 @@ actions:
     description: |
       List host NICS, and which one are candidates for use as external NIC.
     additionalProperties: false
+  list-gpus:
+    description: |
+      List host GPUs
+    additionalProperties: false
   disable:
     description: |
       Prevent new instances from being created.

charms/openstack-hypervisor/src/charm.py

@@ -206,6 +206,10 @@ class HypervisorOperatorCharm(sunbeam_charm.OSBaseOperatorCharm):
             self.on.list_nics_action,
             self._list_nics_action,
         )
+        self.framework.observe(
+            self.on.list_gpus_action,
+            self._list_gpus_action,
+        )
         self.framework.observe(
             self.on.enable_action,
             self._enable_action,
@@ -451,6 +455,17 @@ class HypervisorOperatorCharm(sunbeam_charm.OSBaseOperatorCharm):
         # cli returns a json dict with keys "nics" and "candidate"
         event.set_results({"result": stdout})
 
+    def _list_gpus_action(self, event: ActionEvent):
+        """Run list_gpus action."""
+        try:
+            stdout = self._hypervisor_cli_cmd("list-gpus --format json")
+        except HypervisorError as e:
+            event.fail(str(e))
+            return
+
+        # cli returns a json dict with keys "gpus"
+        event.set_results({"result": stdout})
+
     def _enable_action(self, event: ActionEvent):
         """Run enable action."""
         try:

charms/openstack-hypervisor/tests/unit/test_charm.py

@@ -353,6 +353,8 @@ class TestCharm(test_utils.CharmTestCase):
         }
         with self.assertRaises(ops.testing.ActionFailed):
             self.harness.run_action("list-nics")
+        with self.assertRaises(ops.testing.ActionFailed):
+            self.harness.run_action("list-gpus")
 
     def test_list_nics(self):
         """Check action returns nics."""
@@ -399,6 +401,61 @@ class TestCharm(test_utils.CharmTestCase):
         with self.assertRaises(ops.testing.ActionFailed):
             self.harness.run_action("list-nics")
 
+    def test_list_gpus(self):
+        """Check action returns gpus."""
+        self.harness.begin()
+        hypervisor_snap_mock = MagicMock()
+        hypervisor_snap_mock.present = True
+        epa_orchestrator_snap_mock = MagicMock()
+        epa_orchestrator_snap_mock.present = False
+        self.snap.SnapCache.return_value = {
+            "openstack-hypervisor": hypervisor_snap_mock,
+            "epa-orchestrator": epa_orchestrator_snap_mock,
+        }
+        subprocess_run_mock = MagicMock()
+        subprocess_run_mock.return_value = MagicMock(
+            stdout=bytes(
+                json.dumps(
+                    {
+                        "gpus": [
+                            {
+                                "pci_address": "0000:09:00.0",
+                                "product_id": "0x0534",
+                                "vendor_id": "0x102b",
+                            }
+                        ]
+                    }
+                ),
+                "utf-8",
+            ),
+            stderr=b"yes things went well",
+            returncode=0,
+        )
+        self.subprocess.run = subprocess_run_mock
+        action_output = self.harness.run_action("list-gpus")
+        assert "gpus" in action_output.results["result"]
+
+    def test_list_gpus_error(self):
+        """Check action raises ActionFailed if subprocess returns non-zero."""
+        self.harness.begin()
+        hypervisor_snap_mock = MagicMock()
+        hypervisor_snap_mock.present = True
+        epa_orchestrator_snap_mock = MagicMock()
+        epa_orchestrator_snap_mock.present = False
+        self.snap.SnapCache.return_value = {
+            "openstack-hypervisor": hypervisor_snap_mock,
+            "epa-orchestrator": epa_orchestrator_snap_mock,
+        }
+        subprocess_run_mock = MagicMock()
+        subprocess_run_mock.return_value = MagicMock(
+            stdout=b"",
+            stderr=b"things did not go well",
+            returncode=1,
+        )
+        self.subprocess.run = subprocess_run_mock
+        with self.assertRaises(ops.testing.ActionFailed):
+            self.harness.run_action("list-gpus")
+
     def test_list_flavors(self):
         """Check action return flavors."""
         flavors = "flavor1,flavor2"