feat(agents): declare which driver specs need a per-node agent key

Adds agent_key_node to AbstractPoolDriverSpec (None by default),
overridden by ExordosLocalHyperDriverSpec to return its node. Lets
callers ensure a key generically instead of branching on
isinstance(driver_spec, ExordosLocalHyperDriverSpec).

Author: VasilyStepanov

gcl_sdk/agents/universal/drivers/pool.py

@@ -335,6 +335,12 @@ class AbstractPoolDriverSpec(
 ):
     """Base class for all pool driver specs."""
 
+    @property
+    def agent_key_node(self) -> sys_uuid.UUID | None:
+        """Node uuid whose agent authenticates with a per-node encryption
+        key, or None if this driver kind's agent doesn't need one."""
+        return None
+
 
 class LibvirtPoolDriverSpec(AbstractPoolDriverSpec):
     KIND = "libvirt"
@@ -378,6 +384,10 @@ class ExordosLocalHyperDriverSpec(LibvirtPoolDriverSpec):
 
     node = properties.property(types.UUID(), required=True)
 
+    @property
+    def agent_key_node(self) -> sys_uuid.UUID | None:
+        return self.node
+
 
 class DummyPoolDriverSpec(AbstractPoolDriverSpec):
     KIND = "dummy"

gcl_sdk/tests/unit/agents/drivers/test_pool_driver.py

@@ -122,3 +122,23 @@ def test_local_pool_agent_driver_lists_pool_normally(self, tmp_path):
 
         listed = local_drv.list("pool")
         assert [r.uuid for r in listed] == [pool_uuid]
+
+
+class TestDriverSpecAgentKeyNode:
+    def test_exordos_local_hyper_declares_its_node(self):
+        node = sys_uuid.uuid4()
+        spec = pool_driver.ExordosLocalHyperDriverSpec(
+            connection_uri="qemu:///system", node=node
+        )
+
+        assert spec.agent_key_node == node
+
+    @pytest.mark.parametrize(
+        "spec",
+        [
+            pool_driver.LibvirtPoolDriverSpec(connection_uri="qemu+tcp://127.0.0.1/system"),
+            pool_driver.DummyPoolDriverSpec(),
+        ],
+    )
+    def test_other_kinds_declare_no_node(self, spec):
+        assert spec.agent_key_node is None