Создание машины: диск больше свободного места создаётся только с подтверждением, в шаге «Мощность» видно свободное место; раньше установка падала с ошибкой virt-install

web/app.py

@@ -1273,10 +1273,20 @@ def virt_boot_arg(boot_order: str, is_arm: bool) -> str:
     return value
 
 
+def images_free_bytes() -> int:
+    """Свободное место там, где лежат диски машин."""
+    for path in (IMAGES_DIR, STORAGE_DIR, Path("/")):
+        try:
+            return shutil.disk_usage(path).free
+        except OSError:
+            continue
+    return 0
+
+
 def vm_form_context(request: Request, error: str | None = None, form: dict[str, Any] | None = None, status_code: int = 200):
     profile = host_profile.load_host_profile()
     default_mode = profile.get("recommended_network", "nat")
-    return templates.TemplateResponse(request, "vm_create.html", {"app_name": APP_NAME, "user": AUTH_USER, "isos": list_iso_files(), "disk_images": list_disk_image_files(), "os_types": catalog.OS_TYPES, "boot_options": vm_boot_order_options(), "error": error, "profile": profile, "form": form or {"memory": 4096, "vcpus": 2, "disk_size": 40, "source_type": "iso", "boot_order": "auto", "network_mode": default_mode, "bridge": DEFAULT_BRIDGE}}, status_code=status_code)
+    return templates.TemplateResponse(request, "vm_create.html", {"app_name": APP_NAME, "user": AUTH_USER, "images_free": presenters.format_bytes(images_free_bytes()), "isos": list_iso_files(), "disk_images": list_disk_image_files(), "os_types": catalog.OS_TYPES, "boot_options": vm_boot_order_options(), "error": error, "profile": profile, "form": form or {"memory": 4096, "vcpus": 2, "disk_size": 40, "source_type": "iso", "boot_order": "auto", "network_mode": default_mode, "bridge": DEFAULT_BRIDGE}}, status_code=status_code)
 
 
 # Virtuality noVNC console patch
@@ -1785,12 +1795,16 @@ def vm_create_page(request: Request, iso: str = "", image: str = ""):
 
 
 @app.post("/vm/create", response_class=HTMLResponse)
-def vm_create_submit(request: Request, name: str = Form(...), memory: int = Form(...), vcpus: int = Form(...), disk_size: int = Form(20), iso_path: str = Form(""), disk_image_path: str = Form(""), source_type: str = Form("iso"), boot_order: str = Form("auto"), network_mode: str = Form("nat"), bridge: str = Form(DEFAULT_BRIDGE), os_type: str = Form("linux"), cloud_init: str = Form("0"), ci_user: str = Form(""), ci_password: str = Form(""), ci_ssh_key: str = Form("")):
+def vm_create_submit(request: Request, name: str = Form(...), memory: int = Form(...), vcpus: int = Form(...), disk_size: int = Form(20), iso_path: str = Form(""), disk_image_path: str = Form(""), source_type: str = Form("iso"), boot_order: str = Form("auto"), network_mode: str = Form("nat"), bridge: str = Form(DEFAULT_BRIDGE), os_type: str = Form("linux"), cloud_init: str = Form("0"), ci_user: str = Form(""), ci_password: str = Form(""), ci_ssh_key: str = Form(""), allow_overcommit: str = Form("")):
     auth_redirect = require_auth(request)
     if auth_redirect:
         return auth_redirect
     ci_user = ci_user.strip()
-    form = {"name": name, "memory": memory, "vcpus": vcpus, "disk_size": disk_size, "iso_path": iso_path, "disk_image_path": disk_image_path, "source_type": source_type, "boot_order": boot_order, "network_mode": network_mode, "bridge": bridge, "os_type": os_type, "cloud_init": cloud_init, "ci_user": ci_user, "ci_ssh_key": ci_ssh_key}
+    # Диск qcow2 занимает место по мере заполнения, поэтому больше свободного места его создать можно,
+    # но только осознанно: если машина его заполнит, место на сервере кончится у всех машин.
+    free = images_free_bytes()
+    too_big = disk_size * 1024 ** 3 > free
+    form = {"name": name, "memory": memory, "vcpus": vcpus, "disk_size": disk_size, "iso_path": iso_path, "disk_image_path": disk_image_path, "source_type": source_type, "boot_order": boot_order, "network_mode": network_mode, "bridge": bridge, "os_type": os_type, "cloud_init": cloud_init, "ci_user": ci_user, "ci_ssh_key": ci_ssh_key, "overcommit": too_big, "allow_overcommit": allow_overcommit == "1"}
     error = None
     use_cloud_init = source_type == "disk_image" and cloud_init == "1"
     ssh_keys = cloudinit.parse_ssh_keys(ci_ssh_key) if use_cloud_init else []
@@ -1804,6 +1818,8 @@ def vm_create_submit(request: Request, name: str = Form(...), memory: int = Form
         error = "CPU должен быть от 1 до 128 vCPU."
     elif disk_size < 4 or disk_size > 4096:
         error = "Диск должен быть от 4 GB до 4096 GB."
+    elif too_big and allow_overcommit != "1":
+        error = f"Диск на {disk_size} ГБ больше, чем свободно на сервере ({presenters.format_bytes(free)}). Уменьшите диск или подтвердите создание в шаге «Мощность»."
     elif network_mode not in ("nat", "bridge"):
         error = "Некорректный режим сети."
     elif network_mode == "bridge" and (not bridge or not re.fullmatch(r"[a-zA-Z0-9_.:-]+", bridge)):
@@ -1903,6 +1919,8 @@ def vm_create_submit(request: Request, name: str = Form(...), memory: int = Form
         cmd = ["bash", "-lc", "set -euo pipefail; " + "; ".join(steps)]
     else:
         cmd += ["--disk", f"path={disk_path},size={disk_size},format=qcow2,bus={disk_bus}", "--cdrom", iso_path, "--osinfo", os_info["osinfo"], "--network", network_arg, *graphics]
+        if too_big:
+            cmd += ["--check", "disk_size=off"]  # подтверждено пользователем: virt-install иначе откажется
 
     success_message = "Машина создана" + (f". {login_hint}" if login_hint else "") + (f". Адрес в сети машин: {nat_ip}" if nat_ip else "")
     operation_id = str(uuid.uuid4())