{Monitor} az monitor --help: Args-guided AAZ command tree loading for monitor module

.flake8

@@ -28,3 +28,4 @@ exclude =
     vendored_sdks
     tests
     */command_modules/*/aaz
+    */_legacy

pylintrc

@@ -1,5 +1,5 @@
 [MASTER]
-ignore=tests,generated,vendored_sdks,privates
+ignore=tests,generated,vendored_sdks,privates,_legacy
 ignore-patterns=test.*,azure_devops_build.*
 ignore-paths=.*/command_modules/.*/aaz
 reports=no

src/azure-cli-core/azure/cli/core/aaz/__init__.py

@@ -21,7 +21,8 @@
     AAZPaginationTokenArgFormat
 from ._base import has_value, AAZValuePatch, AAZUndefined
 from ._command import AAZCommand, AAZWaitCommand, AAZCommandGroup, \
-    register_callback, register_command, register_command_group, load_aaz_command_table, link_helper
+    register_callback, register_command, register_command_group, load_aaz_command_table, \
+    load_aaz_command_table_args_guided, link_helper
 from ._field_type import AAZIntType, AAZFloatType, AAZStrType, AAZBoolType, AAZDictType, AAZFreeFormDictType, \
     AAZListType, AAZObjectType, AAZIdentityObjectType, AAZAnyType
 from ._operation import AAZHttpOperation, AAZJsonInstanceUpdateOperation, AAZGenericInstanceUpdateOperation, \

src/azure-cli-core/azure/cli/core/aaz/_command.py

@@ -387,6 +387,181 @@ def decorator(cls):
 AAZ_PACKAGE_FULL_LOAD_ENV_NAME = 'AZURE_AAZ_FULL_LOAD'
 
 
+def load_aaz_command_table_args_guided(loader, aaz_pkg_name, args):
+    """Args-guided AAZ command tree loader.
+
+    Instead of importing the entire AAZ package tree (all __init__.py files which eagerly
+    import all command classes), this function navigates only to the relevant subtree based
+    on CLI args. For example, ``az monitor log-analytics workspace create --help`` only loads
+    the ``workspace`` sub-package and the ``_create`` module, skipping all other commands.
+
+    This requires that AAZ ``__init__.py`` files do NOT contain wildcard imports
+    (``from ._create import *`` etc.) -- they should be empty (just the license header).
+    """
+    profile_pkg = _get_profile_pkg(aaz_pkg_name, loader.cli_ctx.cloud)
+
+    command_table = {}
+    command_group_table = {}
+    if args is None or os.environ.get(AAZ_PACKAGE_FULL_LOAD_ENV_NAME, 'False').lower() == 'true':
+        effective_args = None  # fully load
+    else:
+        effective_args = list(args)
+    if profile_pkg is not None:
+        _load_aaz_by_pkg(loader, profile_pkg, effective_args,
+                         command_table, command_group_table)
+
+    for group_name, command_group in command_group_table.items():
+        loader.command_group_table[group_name] = command_group
+    for command_name, command in command_table.items():
+        loader.command_table[command_name] = command
+    return command_table, command_group_table
+
+
+def _try_import_module(relative_name, package):
+    """Try to import a module by relative name, return None on failure."""
+    try:
+        return importlib.import_module(relative_name, package)
+    except ModuleNotFoundError as ex:
+        # Only treat "module not found" for the requested module as a benign miss.
+        target_mod_name = f"{package}.{relative_name.lstrip('.')}"
+        if ex.name == target_mod_name:
+            return None
+        # Different module is missing; propagate so the real error surfaces.
+        raise
+    except ImportError:
+        logger.error("Error importing module %r from package %r", relative_name, package)
+        raise
+
+
+def _register_from_module(loader, mod, command_table, command_group_table):
+    """Scan a module's namespace for AAZCommand/AAZCommandGroup classes and register them."""
+    for value in mod.__dict__.values():
+        if not isinstance(value, type):
+            continue
+        if value.__module__ != mod.__name__:  # skip imported classes
+            continue
+        if issubclass(value, AAZCommandGroup) and value.AZ_NAME:
+            command_group_table[value.AZ_NAME] = value(cli_ctx=loader.cli_ctx)
+        elif issubclass(value, AAZCommand) and value.AZ_NAME:
+            command_table[value.AZ_NAME] = value(loader=loader)
+
+
+def _get_pkg_children(pkg):
+    """List child entries of a package using pkgutil.
+
+    Returns two sets: (file_stems, subdir_names).
+    - file_stems: module-like stems, e.g. {'_create', '_list', '__cmd_group'}
+    - subdir_names: sub-package directory names, e.g. {'namespace', 'eventhub'}
+    """
+    import pkgutil
+    file_stems = set()
+    subdir_names = set()
+
+    pkg_path = getattr(pkg, '__path__', None)
+    if not pkg_path:
+        return file_stems, subdir_names
+
+    for _importer, name, ispkg in pkgutil.iter_modules(pkg_path):
+        if ispkg:
+            if not name.startswith('_'):
+                subdir_names.add(name)
+        else:
+            file_stems.add(name)
+
+    return file_stems, subdir_names
+
+
+def _load_aaz_by_pkg(loader, pkg, args, command_table, command_group_table):
+    """Recursively navigate the AAZ package tree guided by CLI args.
+
+    - args is None           -> full recursive load of all commands under this package.
+    - args is empty list     -> args exhausted; load current level's commands and sub-group headers.
+    - args has items         -> try to match first arg as a command module or sub-package,
+                                recurse with remaining args on match.
+    - no match on first arg  -> load current level's commands and sub-group headers.
+    """
+    base_module = pkg.__name__
+    file_stems, subdir_names = _get_pkg_children(pkg)
+
+    if args is not None and args and not args[0].startswith('-'):
+        first_arg = args[0].lower().replace('-', '_')
+
+        # First arg matches a command module (e.g. "create" -> "_create")
+        if f"_{first_arg}" in file_stems:
+            mod = _try_import_module(f"._{first_arg}", base_module)
+            if mod:
+                _register_from_module(loader, mod, command_table, command_group_table)
+                return
+
+        # First arg matches a sub-package (command group)
+        if first_arg in subdir_names:
+            sub_module = f"{base_module}.{first_arg}"
+            mod = _try_import_module('.__cmd_group', sub_module)
+            if mod:
+                _register_from_module(loader, mod, command_table, command_group_table)
+            sub_pkg = _try_import_module(f'.{first_arg}', base_module)
+            if sub_pkg:
+                _load_aaz_by_pkg(loader, sub_pkg, args[1:], command_table, command_group_table)
+                return
+
+    # Load __cmd_group + all command modules at this level
+    mod = _try_import_module('.__cmd_group', base_module)
+    if mod:
+        _register_from_module(loader, mod, command_table, command_group_table)
+
+    for stem in file_stems:
+        if stem.startswith('_') and not stem.startswith('__'):
+            mod = _try_import_module(f'.{stem}', base_module)
+            if mod:
+                _register_from_module(loader, mod, command_table, command_group_table)
+
+    for subdir in subdir_names:
+        sub_module = f"{base_module}.{subdir}"
+        if args is None:
+            # Full load -> recurse into every sub-package
+            sub_pkg = _try_import_module(f'.{subdir}', base_module)
+            if sub_pkg:
+                _load_aaz_by_pkg(loader, sub_pkg, None, command_table, command_group_table)
+        else:
+            # Args exhausted / not matched -> load sub-group header and the first
+            # command so the group is non-empty and the parser creates a subparser
+            # for it (required for help output).
+            # TODO: After optimized loading is applied to the whole CLI, revisit
+            # this and consider a lighter approach (e.g. parser-level fix) to
+            # avoid importing one command per trimmed sub-group.
+            mod = _try_import_module('.__cmd_group', sub_module)
+            if mod:
+                _register_from_module(loader, mod, command_table, command_group_table)
+            sub_pkg = _try_import_module(f'.{subdir}', base_module)
+            if sub_pkg:
+                _load_first_command(loader, sub_pkg, command_table)
+
+
+def _load_first_command(loader, pkg, command_table):
+    """Load the first available command module from a package.
+
+    This ensures the command group is non-empty so the parser creates a subparser
+    for it, which is required for it to appear in help output.
+    """
+    file_stems, subdir_names = _get_pkg_children(pkg)
+    base_module = pkg.__name__
+
+    # Try to load a command module at this level first
+    for stem in sorted(file_stems):
+        if stem.startswith('_') and not stem.startswith('__'):
+            mod = _try_import_module(f'.{stem}', base_module)
+            if mod:
+                _register_from_module(loader, mod, command_table, {})
+                return
+
+    # No command at this level, recurse into the first sub-package
+    for subdir in sorted(subdir_names):
+        sub_pkg = _try_import_module(f'.{subdir}', base_module)
+        if sub_pkg:
+            _load_first_command(loader, sub_pkg, command_table)
+            return
+
+
 def load_aaz_command_table(loader, aaz_pkg_name, args):
     """ This function is used in AzCommandsLoader.load_command_table.
     It will load commands in module's aaz package.

src/azure-cli/azure/cli/command_modules/monitor/LEGACY_FALLBACK.md

@@ -0,0 +1,55 @@
+# Monitor Module: Legacy Fallback
+
+## Overview
+
+The monitor module ships a vendored copy of the pre-refactor code in `_legacy/`. Users can switch to this snapshot via config if the refactored implementation causes issues:
+
+```bash
+az config set monitor.use_legacy=true   # enable legacy mode
+az config set monitor.use_legacy=false  # switch back to new mode (default)
+```
+
+A warning is logged each time legacy mode is active.
+
+## How It Works
+
+In `__init__.py`, `MonitorCommandsLoader` reads the `monitor.use_legacy` config (default `false`):
+
+- **New mode** — loads from `aaz/`, `operations/`, and `commands.py` using `load_aaz_command_table_args_guided`.
+- **Legacy mode** — loads from `_legacy/aaz/`, `_legacy/commands.py` using `load_aaz_command_table`. Arguments come from `_legacy/_params.py`.
+
+The `_legacy/` folder is a frozen snapshot extracted from the `dev` branch. All absolute imports were rewritten from `azure.cli.command_modules.monitor.` to `azure.cli.command_modules.monitor._legacy.`.
+
+## Known Adjustments
+
+- **`_legacy/_params.py`**: Removed `monitor metrics alert update` argument registrations (lines for `add_actions`, `remove_actions`, `add_conditions`, `remove_conditions`) because the AAZ `MetricsAlertUpdate._build_arguments_schema` already defines them, and the old-style `action=MetricAlertAddAction` overrides corrupt AAZ argument parsing.
+- **Tests**: `test_monitor_general_operations.py` mocks `gen_guid` at both `azure.cli.command_modules.monitor.operations.monitor_clone_util` and `azure.cli.command_modules.monitor._legacy.operations.monitor_clone_util` so tests pass in either mode.
+- **Linting**: `_legacy/` is excluded via `pylintrc` (`ignore` list) and `.flake8` (`exclude` list).
+
+## Dropping Legacy Support
+
+When legacy mode is no longer needed:
+
+1. **Delete the `_legacy/` folder**:
+   ```bash
+   rm -rf src/azure-cli/azure/cli/command_modules/monitor/_legacy/
+   ```
+
+2. **Simplify `__init__.py`** — remove `_use_legacy`, `_load_legacy_command_table`, and the dispatch in `load_command_table` / `load_arguments`. Inline `_load_new_command_table` as the sole `load_command_table`:
+   ```python
+   # Remove these
+   _CONFIG_SECTION = 'monitor'
+   _USE_LEGACY_CONFIG_KEY = 'use_legacy'
+   self._use_legacy = ...
+   def _load_legacy_command_table(self, args): ...
+
+   # Keep only _load_new_command_table logic directly in load_command_table
+   ```
+
+3. **Clean up tests** — remove the second `mock.patch` line for `_legacy` in `test_monitor_general_operations.py`:
+   ```python
+   # Remove this line from each mock.patch block:
+   mock.patch('azure.cli.command_modules.monitor._legacy.operations.monitor_clone_util.gen_guid', ...)
+   ```
+
+4. **Revert linter config** — remove `_legacy` from `pylintrc` `ignore` and `*/_legacy` from `.flake8` `exclude`.

src/azure-cli/azure/cli/command_modules/monitor/__init__.py

@@ -3,10 +3,16 @@
 # Licensed under the MIT License. See License.txt in the project root for license information.
 # --------------------------------------------------------------------------------------------
 
+from knack.log import get_logger
+
 from azure.cli.core import AzCommandsLoader
 from azure.cli.core.commands import AzArgumentContext, CliCommandType
+from azure.cli.command_modules.monitor._help import helps   # pylint: disable=unused-import
+
+logger = get_logger(__name__)
 
-from azure.cli.command_modules.monitor._help import helps  # pylint: disable=unused-import
+_CONFIG_SECTION = 'monitor'
+_USE_LEGACY_CONFIG_KEY = 'use_legacy'
 
 
 # pylint: disable=line-too-long
@@ -33,31 +39,84 @@ class MonitorCommandsLoader(AzCommandsLoader):
 
     def __init__(self, cli_ctx=None):
         from azure.cli.core.profiles import ResourceType
-        monitor_custom = CliCommandType(
-            operations_tmpl='azure.cli.command_modules.monitor.custom#{}')
+        self._use_legacy = cli_ctx.config.getboolean(
+            _CONFIG_SECTION, _USE_LEGACY_CONFIG_KEY, fallback=False) if cli_ctx else False
+        if self._use_legacy:
+            monitor_custom = CliCommandType(
+                operations_tmpl='azure.cli.command_modules.monitor._legacy.custom#{}')
+        else:
+            monitor_custom = CliCommandType(
+                operations_tmpl='azure.cli.command_modules.monitor.custom#{}')
         super().__init__(cli_ctx=cli_ctx,
                          resource_type=ResourceType.MGMT_MONITOR,
                          argument_context_cls=MonitorArgumentContext,
                          custom_command_type=monitor_custom)
 
     def load_command_table(self, args):
-        from azure.cli.command_modules.monitor.commands import load_command_table
+        if self._use_legacy:
+            return self._load_legacy_command_table(args)
+        return self._load_new_command_table(args)
+
+    def _load_legacy_command_table(self, args):
+        """Load commands from the vendored _legacy snapshot (pre-refactor code from dev branch)."""
         from azure.cli.core.aaz import load_aaz_command_table
+
+        logger.warning(
+            "The monitor module is using legacy mode. "
+            "To switch to the new optimized implementation, run: "
+            "az config set %s.%s=false",
+            _CONFIG_SECTION, _USE_LEGACY_CONFIG_KEY)
+
+        try:
+            from ._legacy import aaz as legacy_aaz
+        except ImportError:
+            legacy_aaz = None
+        if legacy_aaz:
+            load_aaz_command_table(
+                loader=self,
+                aaz_pkg_name=legacy_aaz.__name__,
+                args=args
+            )
+
+        from ._legacy.commands import load_command_table
+        load_command_table(self, args)
+        return self.command_table
+
+    def _load_new_command_table(self, args):
+        """Load commands from the current (refactored) implementation."""
+        from azure.cli.command_modules.monitor.commands import load_command_table
+        from azure.cli.core.aaz import load_aaz_command_table_args_guided
+
         try:
             from . import aaz
         except ImportError:
             aaz = None
         if aaz:
-            load_aaz_command_table(
+            load_aaz_command_table_args_guided(
                 loader=self,
                 aaz_pkg_name=aaz.__name__,
                 args=args
             )
+
+        try:
+            from . import operations
+        except ImportError:
+            operations = None
+        if operations:
+            load_aaz_command_table_args_guided(
+                loader=self,
+                aaz_pkg_name=operations.__name__,
+                args=args
+            )
+
         load_command_table(self, args)
         return self.command_table
 
     def load_arguments(self, command):
-        from azure.cli.command_modules.monitor._params import load_arguments
+        if self._use_legacy:
+            from azure.cli.command_modules.monitor._legacy._params import load_arguments
+        else:
+            from azure.cli.command_modules.monitor._params import load_arguments
         load_arguments(self, command)