feat: implement resource resizing for VMs with storage management

- Added KnownHostsManager to handle cleanup of SSH known_hosts entries upon VM deletion.
- Introduced disk_size_bytes method in ImageStore to read logical disk capacity.
- Enhanced LifecycleService to manage VM resource resizing, including CPU, RAM, and storage.
- Updated application configuration to support known_hosts_files for SSH management.
- Modified dashboard to include resource resizing options in the UI.
- Improved error handling and validation for resource inputs in the dashboard.
- Removed obsolete .pyc files from the repository.

uvm/lifecycle.py

@@ -19,6 +19,7 @@ from .firecracker.config import build_config, write_config
 from .firecracker.process import FirecrackerProcessManager, ProcessInfo
 from .images import ImageStore
 from .integrity import load_manifest, verify_file
+from .known_hosts import KnownHostsManager
 from .network import NetworkManager
 from .state import StateStore
 from .system import check_kvm, ensure_data_directories, require_root
@@ -55,6 +56,7 @@ class LifecycleService:
     def __init__(
         self, settings: Settings, state_store: StateStore, images: ImageStore,
         network: NetworkManager, process: FirecrackerProcessManager, *,
+        known_hosts: KnownHostsManager,
         client_factory: Callable[[Path, float], FirecrackerClient] = FirecrackerClient,
         clock: Callable[[], float] = time.time,
     ) -> None:
@@ -63,6 +65,7 @@ class LifecycleService:
         self._images = images
         self._network = network
         self._process = process
+        self._known_hosts = known_hosts
         self._client_factory = client_factory
         self._clock = clock
 
@@ -251,7 +254,7 @@ class LifecycleService:
             previous = vm.pending_resize
             capacity = previous.storage_mib if previous is not None else vm.storage_mib
             if capacity is None:
-                capacity = max(MIN_STORAGE_MIB, (Path(vm.disk).stat().st_size + 1024 * 1024 - 1) // (1024 * 1024))
+                capacity = max(MIN_STORAGE_MIB, (self._images.disk_size_bytes(Path(vm.disk)) + 1024 * 1024 - 1) // (1024 * 1024))
             vm.pending_resize = VmResources(
                 cpu=cpu if cpu is not None else previous.cpu if previous is not None else vm.cpu,
                 ram_mib=ram_mib if ram_mib is not None else previous.ram_mib if previous is not None else vm.ram_mib,
@@ -284,7 +287,11 @@ class LifecycleService:
             return
         if self._process.observe(vm) != "gone":
             raise ConflictError("cannot resize a disk without confirmed process exit")
-        if target.storage_mib != vm.storage_mib:
+        # A prior attempt may have published a resized image without saving
+        # its allocation. Check the disk too, including when a retry changes
+        # the target back to the previously recorded capacity.
+        if (target.storage_mib != vm.storage_mib
+                or self._images.disk_size_bytes(Path(vm.disk)) != target.storage_mib * 1024 * 1024):
             self._images.resize_vm_disk(Path(vm.disk), target.storage_mib)
         vm.cpu, vm.ram_mib, vm.storage_mib = target.cpu, target.ram_mib, target.storage_mib
         vm.pending_resize = None
@@ -301,6 +308,7 @@ class LifecycleService:
         try:
             self._cleanup_runtime(vm, timeout=timeout)
             self._remove_runtime(vm)
+            self._known_hosts.remove(vm)
             self._remove_record(vm.id)
             return vm
         except BaseException as error: