feat: update terminal support messaging and enhance guest agent provisioning logic

tests/test_guest_exec_lifecycle.py

@@ -4,7 +4,7 @@ from pathlib import Path
 from unittest.mock import Mock
 
 from tests.test_lifecycle import LifecycleTestCase
-from uvm.errors import ConflictError, GuestAgentUnavailableError, GuestExecutionError, NotFoundError
+from uvm.errors import ConflictError, GuestAgentUnavailableError, GuestExecutionError, NotFoundError, UvmError
 from uvm.guest_exec import ExecResult
 
 
@@ -22,6 +22,65 @@ class GuestExecLifecycleTests(LifecycleTestCase):
         vm = self.create_vm(username="worker")
         self.assert_call_order(vm, "images.provision_agent", "process.start")
 
+    def test_stopped_boots_automatically_provision_agent_before_starting_the_vmm(self) -> None:
+        vm = self.create_vm(username="worker", password="retained-password")
+        identity = (vm.id, vm.guest_ip, vm.mac, vm.username, vm.password)
+
+        def provision(disk, vm_id, username):
+            self.host.call("images.provision_agent", vm_id)
+            record = self.store.get(vm_id)
+            self.assertTrue(self.store.operation_active)
+            self.assertEqual(self.process.observe(record), "gone")
+            self.assertEqual((record.id, record.guest_ip, record.mac, record.username, record.password), identity)
+            self.assertEqual((disk, username), (Path(vm.disk), "worker"))
+
+        self.provision_agent.side_effect = provision
+        for action in ("start", "restart", "resize"):
+            with self.subTest(action=action):
+                if action == "start":
+                    self.service.stop(vm.id)
+                self.host.events.clear()
+                self.provision_agent.reset_mock()
+                self.provision.reset_mock()
+                if action == "resize":
+                    started = self.service.resize(vm.id, cpu=2)
+                else:
+                    started = getattr(self.service, action)(vm.id)
+                self.assertEqual(started.status, "running")
+                self.provision_agent.assert_called_once_with(Path(vm.disk), vm.id, "worker")
+                self.provision.assert_not_called()
+                self.assert_call_order(vm, "images.provision_agent", "process.start")
+
+    def test_live_or_ambiguous_vms_never_run_offline_agent_provisioning(self) -> None:
+        vm = self.create_vm()
+        self.provision_agent.reset_mock()
+        self.service.start(vm.id)
+        self.process.unknown.add(vm.id)
+        with self.assertRaises(ConflictError):
+            self.service.start(vm.id)
+        self.provision_agent.assert_not_called()
+
+    def test_default_agent_setup_failure_blocks_boot_and_keeps_the_retained_disk(self) -> None:
+        vm = self.create_vm()
+        self.service.stop(vm.id)
+        before = Path(vm.disk).read_bytes()
+        count = len(self.process.started)
+        self.provision_agent.side_effect = UvmError("agent setup failed")
+        with self.assertRaisesRegex(UvmError, "agent setup failed"):
+            self.service.start(vm.id)
+        self.assertEqual(len(self.process.started), count)
+        self.assertEqual(Path(vm.disk).read_bytes(), before)
+        self.assertEqual(self.store.get(vm.id).status, "failed")
+        self.provision_agent.side_effect = None
+        self.assertEqual(self.service.start(vm.id).status, "running")
+
+    def test_default_agent_setup_failure_rolls_back_a_new_vm_before_boot(self) -> None:
+        self.provision_agent.side_effect = UvmError("unsupported guest image")
+        with self.assertRaisesRegex(UvmError, "unsupported guest image"):
+            self.create_vm()
+        self.assertEqual(self.store.load().vms, {})
+        self.assertEqual(self.process.started, [])
+
     def test_execution_pins_the_exact_vm_under_lock_and_waits_without_holding_it(self) -> None:
         vm = self.create_vm(name="worker", ports=())
         result = ExecResult(7, "output", "problem", False, False)