install: use standard Python classes to declare knob types

Use type(None) rather than bool to define knobs which are represented as
command line flags. This allows declaring both "--option" and
"--option={0,1}"-style command line options.

Use enum.Enum subclasses instead of set literals to declare enumerations.

Use typing.List[T] instead of (list, T) to declare lists. (Note that a
minimal reimplementation of typing.List is used instead of the Python 2
backport of the typing module due to non-technical reasons.)

Use CheckedIPAddress instead of 'ip' and 'ip-local' to declare IP
addresses.

https://fedorahosted.org/freeipa/ticket/6392

Reviewed-By: Martin Basti <mbasti@redhat.com>

1 files changed, 33 insertions, 3 deletions

diff --git a/ipapython/install/core.py b/ipapython/install/core.py
index c3dc90846..111b71090 100644
--- a/ipapython/install/core.py
+++ b/ipapython/install/core.py
@@ -8,20 +8,25 @@ The framework core.
 
 import abc
 import collections
+import enum
 import functools
 import itertools
+import re
 import sys
 
 import six
 
 from ipapython.ipa_log_manager import root_logger
+from ipapython.ipautil import CheckedIPAddress
 
-from . import util
+from . import util, typing
 from .util import from_
 
 __all__ = ['InvalidStateError', 'KnobValueError', 'Property', 'Knob',
            'Configurable', 'Group', 'Component', 'Composite']
 
+NoneType = type(None)
+
 # Configurable states
 _VALIDATE_PENDING = 'VALIDATE_PENDING'
 _VALIDATE_RUNNING = 'VALIDATE_RUNNING'
@@ -145,11 +150,15 @@ def knob(type_or_base, default=_missing, sensitive=_missing,
          deprecated=_missing, description=_missing, cli_positional=_missing,
          cli_name=_missing, cli_short_name=_missing, cli_aliases=_missing,
          cli_metavar=_missing):
+    if type_or_base is None:
+        type_or_base = NoneType
+
+    assert isinstance(type_or_base, type)
+
     class_dict = {}
     class_dict['_order'] = next(_counter)
 
-    if (not isinstance(type_or_base, type) or
-            not issubclass(type_or_base, KnobBase)):
+    if not issubclass(type_or_base, KnobBase):
         class_dict['type'] = type_or_base
         type_or_base = KnobBase
 
@@ -179,6 +188,27 @@ def Knob(type_or_base, default=_missing, sensitive=_missing,
          deprecated=_missing, description=_missing, cli_positional=_missing,
          cli_name=_missing, cli_short_name=_missing, cli_aliases=_missing,
          cli_metavar=_missing):
+    if isinstance(type_or_base, tuple):
+        assert type_or_base[0] is list
+        scalar_type = type_or_base[1]
+    else:
+        scalar_type = type_or_base
+
+    if scalar_type is bool:
+        scalar_type = NoneType
+    elif scalar_type == 'ip':
+        scalar_type = CheckedIPAddress
+    elif isinstance(scalar_type, set):
+        scalar_type = type(
+            'Enum',
+            (enum.Enum,),
+            {re.sub(r'[^0-9A-Za-z_]', '', n): n for n in scalar_type})
+
+    if isinstance(type_or_base, tuple):
+        type_or_base = typing.List[scalar_type]
+    else:
+        type_or_base = scalar_type
+
     return knob(type_or_base,
                 default=default,
                 sensitive=sensitive,