Implement internal form spec MonitoredHostExtended

`MonitoredHostExtended` is effectively an extension of `MonitoredHost` with the
option to specify a default value.

CMK-19497

Change-Id: I78e8db6fa64e5db8261ea092aeea7140743e8c26

cmk/gui/form_specs/private/__init__.py

@@ -14,6 +14,7 @@
 from .dictionary_extended import DictionaryExtended
 from .list_extended import ListExtended
 from .list_of_strings import ListOfStrings
+from .monitored_host_extended import MonitoredHostExtended
 from .multiple_choice import AdaptiveMultipleChoice, AdaptiveMultipleChoiceLayout
 from .optional_choice import OptionalChoice
 from .string_autocompleter import StringAutocompleter
@@ -35,4 +36,5 @@
     "not_empty",
     "AdaptiveMultipleChoice",
     "AdaptiveMultipleChoiceLayout",
+    "MonitoredHostExtended",
 ]

cmk/gui/form_specs/private/monitored_host_extended.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python3
+# Copyright (C) 2024 Checkmk GmbH - License: GNU General Public License v2
+# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
+# conditions defined in the file COPYING, which is part of this source code package.
+
+from dataclasses import dataclass
+
+from cmk.rulesets.v1.form_specs import DefaultValue, FormSpec
+
+
+@dataclass(frozen=True, kw_only=True)
+class MonitoredHostExtended(FormSpec[str]):
+    prefill: DefaultValue[str]

cmk/gui/utils/rule_specs/legacy_converter.py

@@ -26,6 +26,7 @@
     DictionaryExtended,
     ListExtended,
     ListOfStrings,
+    MonitoredHostExtended,
 )
 from cmk.gui.form_specs.vue.shared_type_defs import ListOfStringsLayout
 from cmk.gui.form_specs.vue.visitors import DefaultValue as VueDefaultValue
@@ -747,7 +748,7 @@ def _convert_to_inner_legacy_valuespec(
         case ruleset_api_v1.form_specs.Metric():
             return _convert_to_legacy_metric_name(to_convert, localizer)
 
-        case ruleset_api_v1.form_specs.MonitoredHost():
+        case ruleset_api_v1.form_specs.MonitoredHost() | MonitoredHostExtended():
             return _convert_to_legacy_monitored_host_name(to_convert, localizer)
 
         case ruleset_api_v1.form_specs.MonitoredService():
@@ -2205,7 +2206,7 @@ def _convert_to_legacy_metric_name(
 
 
 def _convert_to_legacy_monitored_host_name(
-    to_convert: ruleset_api_v1.form_specs.MonitoredHost,
+    to_convert: ruleset_api_v1.form_specs.MonitoredHost | MonitoredHostExtended,
     localizer: Callable[[str], str],
 ) -> legacy_valuespecs.MonitoredHostname:
     converted_kwargs: dict[str, Any] = {
@@ -2223,6 +2224,8 @@ def _convert_to_legacy_monitored_host_name(
     if (title := _localize_optional(to_convert.title, localizer)) is None:
         title = ruleset_api_v1.Title("Host name").localize(localizer)
     converted_kwargs["title"] = title
+    if isinstance(to_convert, MonitoredHostExtended):
+        converted_kwargs["default_value"] = to_convert.prefill.value
 
     return legacy_valuespecs.MonitoredHostname(**converted_kwargs)