fix(monitor): refresh the VM/LXC modal after edits made outside the Monitor

AppImage/scripts/flask_server.py

@@ -1913,6 +1913,35 @@ def _vm_cache_put(cache: dict, vmid: int, value) -> None:
     with _vm_modal_cache_lock:
         cache[vmid] = (time.time(), value)
 
+# The details and mount-point caches come from the guest's .conf, and an edit
+# made from the Proxmox interface or `pct/qm set` raises no event the Monitor
+# sees. Each entry remembers the .conf it was built from and is rebuilt when
+# the file changes.
+_vm_conf_built: dict = {}   # (cache name, vmid) -> .conf signature
+
+def _vm_conf_signature(vmid: int):
+    for path in (f'/etc/pve/lxc/{int(vmid)}.conf', f'/etc/pve/qemu-server/{int(vmid)}.conf'):
+        try:
+            info = os.stat(path)
+        except OSError:
+            continue
+        return (info.st_mtime_ns, info.st_size)
+    return None
+
+def _vm_conf_cache_get(cache: dict, name: str, vmid: int, ttl: int):
+    """Cached payload for vmid only while its .conf is unchanged."""
+    cached = _vm_cache_get(cache, vmid, ttl)
+    if cached is None:
+        return None
+    with _vm_modal_cache_lock:
+        built = _vm_conf_built.get((name, vmid))
+    return cached if built == _vm_conf_signature(vmid) else None
+
+def _vm_conf_cache_put(cache: dict, name: str, vmid: int, value, signature) -> None:
+    _vm_cache_put(cache, vmid, value)
+    with _vm_modal_cache_lock:
+        _vm_conf_built[(name, vmid)] = signature
+
 def _vm_cache_invalidate(vmid: int, *caches) -> None:
     """Drop this vmid's entries from the given caches. With no argument
     hits every per-VM modal cache — used by write actions that could
@@ -15214,7 +15243,7 @@ def api_vms_modal_cache_all():
             entry = {
                 'vmid': vmid,
                 'type': vm_type,
-                'details': _vm_cache_get(_vm_details_cache, vmid, _VM_DETAILS_TTL),
+                'details': _vm_conf_cache_get(_vm_details_cache, 'details', vmid, _VM_DETAILS_TTL),
                 'backups': _vm_cache_get(_vm_backups_cache, vmid, _VM_BACKUPS_TTL),
             }
             if vm_type == 'lxc':
@@ -15225,7 +15254,7 @@ def api_vms_modal_cache_all():
                     _VM_APP_SUGGESTIONS_TTL,
                 )
                 entry['schedule'] = _vm_cache_get(_vm_schedule_cache, vmid, _VM_SCHEDULE_TTL)
-                entry['mount_points'] = _vm_cache_get(_vm_mounts_cache, vmid, _VM_MOUNTS_TTL)
+                entry['mount_points'] = _vm_conf_cache_get(_vm_mounts_cache, 'mounts', vmid, _VM_MOUNTS_TTL)
             guests.append(entry)
         return jsonify({'guests': guests, 'ts': int(time.time())})
     except Exception as e:
@@ -15238,7 +15267,9 @@ def api_vms_modal_cache_all():
 def get_vm_config(vmid):
     """Get detailed configuration for a specific VM/LXC"""
     try:
-        cached = _vm_cache_get(_vm_details_cache, vmid, _VM_DETAILS_TTL)
+        # Taken before reading the .conf, so an edit during the build is seen next time.
+        signature = _vm_conf_signature(vmid)
+        cached = _vm_conf_cache_get(_vm_details_cache, 'details', vmid, _VM_DETAILS_TTL)
         if cached is not None:
             return jsonify(cached)
 
@@ -15308,7 +15339,7 @@ def get_vm_config(vmid):
         if hardware_info:
             response_data['hardware_info'] = hardware_info
 
-        _vm_cache_put(_vm_details_cache, vmid, response_data)
+        _vm_conf_cache_put(_vm_details_cache, 'details', vmid, response_data, signature)
         return jsonify(response_data)
 
     except Exception as e:
@@ -15328,7 +15359,8 @@ def api_lxc_mount_points(vmid):
     start/stop of the guest, since config-visible fields normally
     only change through a guest reboot). The runtime endpoint is
     NEVER cached — it must reflect the live state at click time."""
-    cached = _vm_cache_get(_vm_mounts_cache, vmid, _VM_MOUNTS_TTL)
+    signature = _vm_conf_signature(vmid)
+    cached = _vm_conf_cache_get(_vm_mounts_cache, 'mounts', vmid, _VM_MOUNTS_TTL)
     if cached is not None:
         return jsonify(cached)
     try:
@@ -15339,7 +15371,7 @@ def api_lxc_mount_points(vmid):
         result = lxc_mount_points.get_lxc_mount_points_static(str(vmid))
         if not result.get("ok"):
             return jsonify(result), 400
-        _vm_cache_put(_vm_mounts_cache, vmid, result)
+        _vm_conf_cache_put(_vm_mounts_cache, 'mounts', vmid, result, signature)
         return jsonify(result)
     except Exception as e:
         return jsonify({"ok": False, "error": str(e)}), 500

AppImage/scripts/tests/test_vm_conf_cache.py

@@ -0,0 +1,60 @@
+"""The VM/LXC modal caches notice a .conf edited outside the Monitor."""
+import ast
+from pathlib import Path
+import threading
+import time
+from types import SimpleNamespace
+import unittest
+
+SERVER = Path(__file__).resolve().parents[1] / 'flask_server.py'
+NAMES = ('_vm_cache_get', '_vm_cache_put', '_vm_conf_signature', '_vm_conf_cache_get', '_vm_conf_cache_put')
+
+
+class ConfAwareCacheTests(unittest.TestCase):
+    def setUp(self):
+        tree = ast.parse(SERVER.read_text(encoding='utf-8'))
+        nodes = [n for n in tree.body if isinstance(n, ast.FunctionDef) and n.name in NAMES]
+        self.assertEqual(sorted(n.name for n in nodes), sorted(NAMES))
+        self.files = {'/etc/pve/lxc/111.conf': (1, 300)}
+
+        def stat(path):
+            if path not in self.files:
+                raise OSError(path)
+            mtime, size = self.files[path]
+            return SimpleNamespace(st_mtime_ns=mtime, st_size=size)
+
+        self.scope = {'os': SimpleNamespace(stat=stat), 'time': time, '_vm_modal_cache_lock': threading.Lock(),
+                      '_vm_conf_built': {}}
+        exec(compile(ast.Module(body=nodes, type_ignores=[]), str(SERVER), 'exec'), self.scope)
+        self.cache = {}
+
+    def build(self, value):
+        signature = self.scope['_vm_conf_signature'](111)
+        self.scope['_vm_conf_cache_put'](self.cache, 'details', 111, value, signature)
+
+    def get(self):
+        return self.scope['_vm_conf_cache_get'](self.cache, 'details', 111, 10 ** 9)
+
+    def test_unchanged_conf_serves_the_cache(self):
+        self.build({'onboot': 1})
+        self.assertEqual(self.get(), {'onboot': 1})
+
+    def test_conf_edited_outside_the_monitor_drops_the_entry(self):
+        self.build({'onboot': 1})
+        self.files['/etc/pve/lxc/111.conf'] = (2, 300)   # `pct set 111 --onboot 0`
+        self.assertIsNone(self.get())
+        self.build({'onboot': 0})
+        self.assertEqual(self.get(), {'onboot': 0})
+
+    def test_entry_without_a_recorded_conf_is_rebuilt(self):
+        self.scope['_vm_cache_put'](self.cache, 111, {'old': True})
+        self.assertIsNone(self.get())
+
+    def test_vm_conf_path_and_missing_guest(self):
+        self.files = {'/etc/pve/qemu-server/200.conf': (5, 10)}
+        self.assertEqual(self.scope['_vm_conf_signature'](200), (5, 10))
+        self.assertIsNone(self.scope['_vm_conf_signature'](999))
+
+
+if __name__ == '__main__':
+    unittest.main()