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community.general/plugins/module_utils/module_helper.py
patchback[bot] d2cdca416c
Applying ModuleHelper variable mgmt to xfconf -> improvements on MH (#2188) (#2191)
* applying MH variable mgmt to xfconf - improvements on MH

* added changelog fragment

(cherry picked from commit 9aec9b502e)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>
2021-04-06 21:51:12 +02:00

502 lines
16 KiB
Python

# -*- coding: utf-8 -*-
# (c) 2020, Alexei Znamensky <russoz@gmail.com>
# Copyright: (c) 2020, Ansible Project
# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
from __future__ import absolute_import, division, print_function
__metaclass__ = type
from functools import partial, wraps
import traceback
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.common.dict_transformations import dict_merge
class ModuleHelperException(Exception):
@staticmethod
def _get_remove(key, kwargs):
if key in kwargs:
result = kwargs[key]
del kwargs[key]
return result
return None
def __init__(self, *args, **kwargs):
self.msg = self._get_remove('msg', kwargs) or "Module failed with exception: {0}".format(self)
self.update_output = self._get_remove('update_output', kwargs) or {}
super(ModuleHelperException, self).__init__(*args)
class ArgFormat(object):
"""
Argument formatter for use as a command line parameter. Used in CmdMixin.
"""
BOOLEAN = 0
PRINTF = 1
FORMAT = 2
@staticmethod
def stars_deco(num):
if num == 1:
def deco(f):
return lambda v: f(*v)
return deco
elif num == 2:
def deco(f):
return lambda v: f(**v)
return deco
return lambda f: f
def __init__(self, name, fmt=None, style=FORMAT, stars=0):
"""
Creates a CLI-formatter for one specific argument. The argument may be a module parameter or just a named parameter for
the CLI command execution.
:param name: Name of the argument to be formatted
:param fmt: Either a str to be formatted (using or not printf-style) or a callable that does that
:param style: Whether arg_format (as str) should use printf-style formatting.
Ignored if arg_format is None or not a str (should be callable).
:param stars: A int with 0, 1 or 2 value, indicating to formatting the value as: value, *value or **value
"""
def printf_fmt(_fmt, v):
try:
return [_fmt % v]
except TypeError as e:
if e.args[0] != 'not all arguments converted during string formatting':
raise
return [_fmt]
_fmts = {
ArgFormat.BOOLEAN: lambda _fmt, v: ([_fmt] if bool(v) else []),
ArgFormat.PRINTF: printf_fmt,
ArgFormat.FORMAT: lambda _fmt, v: [_fmt.format(v)],
}
self.name = name
self.stars = stars
if fmt is None:
fmt = "{0}"
style = ArgFormat.FORMAT
if isinstance(fmt, str):
func = _fmts[style]
self.arg_format = partial(func, fmt)
elif isinstance(fmt, list) or isinstance(fmt, tuple):
self.arg_format = lambda v: [_fmts[style](f, v)[0] for f in fmt]
elif hasattr(fmt, '__call__'):
self.arg_format = fmt
else:
raise TypeError('Parameter fmt must be either: a string, a list/tuple of '
'strings or a function: type={0}, value={1}'.format(type(fmt), fmt))
if stars:
self.arg_format = (self.stars_deco(stars))(self.arg_format)
def to_text(self, value):
if value is None:
return []
func = self.arg_format
return [str(p) for p in func(value)]
def cause_changes(func, on_success=True, on_failure=False):
@wraps(func)
def wrapper(self, *args, **kwargs):
try:
func(*args, **kwargs)
if on_success:
self.changed = True
except Exception:
if on_failure:
self.changed = True
raise
return wrapper
def module_fails_on_exception(func):
@wraps(func)
def wrapper(self, *args, **kwargs):
try:
func(self, *args, **kwargs)
except SystemExit:
raise
except ModuleHelperException as e:
if e.update_output:
self.update_output(e.update_output)
self.module.fail_json(msg=e.msg, exception=traceback.format_exc(),
output=self.output, vars=self.vars.output(), **self.output)
except Exception as e:
msg = "Module failed with exception: {0}".format(str(e).strip())
self.module.fail_json(msg=msg, exception=traceback.format_exc(),
output=self.output, vars=self.vars.output(), **self.output)
return wrapper
class DependencyCtxMgr(object):
def __init__(self, name, msg=None):
self.name = name
self.msg = msg
self.has_it = False
self.exc_type = None
self.exc_val = None
self.exc_tb = None
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.has_it = exc_type is None
self.exc_type = exc_type
self.exc_val = exc_val
self.exc_tb = exc_tb
return not self.has_it
@property
def text(self):
return self.msg or str(self.exc_val)
class VarMeta(object):
NOTHING = object()
def __init__(self, diff=False, output=True, change=None, fact=False):
self.init = False
self.initial_value = None
self.value = None
self.diff = diff
self.change = diff if change is None else change
self.output = output
self.fact = fact
def set(self, diff=None, output=None, change=None, fact=None, initial_value=NOTHING):
if diff is not None:
self.diff = diff
if output is not None:
self.output = output
if change is not None:
self.change = change
if fact is not None:
self.fact = fact
if initial_value is not self.NOTHING:
self.initial_value = initial_value
def set_value(self, value):
if not self.init:
self.initial_value = value
self.init = True
self.value = value
return self
@property
def has_changed(self):
return self.change and (self.initial_value != self.value)
@property
def diff_result(self):
return None if not (self.diff and self.has_changed) else {
'before': self.initial_value,
'after': self.value,
}
def __str__(self):
return "<VarMeta: value={0}, initial={1}, diff={2}, output={3}, change={4}>".format(
self.value, self.initial_value, self.diff, self.output, self.change
)
class ModuleHelper(object):
_output_conflict_list = ('msg', 'exception', 'output', 'vars', 'changed')
_dependencies = []
module = None
facts_name = None
output_params = ()
diff_params = ()
change_params = ()
facts_params = ()
class VarDict(object):
def __init__(self):
self._data = dict()
self._meta = dict()
def __getitem__(self, item):
return self._data[item]
def __setitem__(self, key, value):
self.set(key, value)
def __getattr__(self, item):
try:
return self._data[item]
except KeyError:
return getattr(self._data, item)
def __setattr__(self, key, value):
if key in ('_data', '_meta'):
super(ModuleHelper.VarDict, self).__setattr__(key, value)
else:
self.set(key, value)
def meta(self, name):
return self._meta[name]
def set_meta(self, name, **kwargs):
self.meta(name).set(**kwargs)
def set(self, name, value, **kwargs):
if name in ('_data', '_meta'):
raise ValueError("Names _data and _meta are reserved for use by ModuleHelper")
self._data[name] = value
if name in self._meta:
meta = self.meta(name)
else:
meta = VarMeta(**kwargs)
meta.set_value(value)
self._meta[name] = meta
def output(self):
return dict((k, v) for k, v in self._data.items() if self.meta(k).output)
def diff(self):
diff_results = [(k, self.meta(k).diff_result) for k in self._data]
diff_results = [dr for dr in diff_results if dr[1] is not None]
if diff_results:
before = dict((dr[0], dr[1]['before']) for dr in diff_results)
after = dict((dr[0], dr[1]['after']) for dr in diff_results)
return {'before': before, 'after': after}
return None
def facts(self):
facts_result = dict((k, v) for k, v in self._data.items() if self._meta[k].fact)
return facts_result if facts_result else None
def change_vars(self):
return [v for v in self._data if self.meta(v).change]
def has_changed(self, v):
return self._meta[v].has_changed
def __init__(self, module=None):
self.vars = ModuleHelper.VarDict()
self._changed = False
if module:
self.module = module
if not isinstance(self.module, AnsibleModule):
self.module = AnsibleModule(**self.module)
for name, value in self.module.params.items():
self.vars.set(
name, value,
diff=name in self.diff_params,
output=name in self.output_params,
change=None if not self.change_params else name in self.change_params,
fact=name in self.facts_params,
)
def update_vars(self, meta=None, **kwargs):
if meta is None:
meta = {}
for k, v in kwargs.items():
self.vars.set(k, v, **meta)
def update_output(self, **kwargs):
self.update_vars(meta={"output": True}, **kwargs)
def update_facts(self, **kwargs):
self.update_vars(meta={"fact": True}, **kwargs)
def __init_module__(self):
pass
def __run__(self):
raise NotImplementedError()
def __quit_module__(self):
pass
def _vars_changed(self):
return any(self.vars.has_changed(v) for v in self.vars.change_vars())
@property
def changed(self):
return self._changed
@changed.setter
def changed(self, value):
self._changed = value
def has_changed(self):
return self.changed or self._vars_changed()
@property
def output(self):
result = dict(self.vars.output())
if self.facts_name:
facts = self.vars.facts()
if facts is not None:
result['ansible_facts'] = {self.facts_name: facts}
if self.module._diff:
diff = result.get('diff', {})
vars_diff = self.vars.diff() or {}
result['diff'] = dict_merge(dict(diff), vars_diff)
for varname in result:
if varname in self._output_conflict_list:
result["_" + varname] = result[varname]
del result[varname]
return result
@module_fails_on_exception
def run(self):
self.fail_on_missing_deps()
self.__init_module__()
self.__run__()
self.__quit_module__()
self.module.exit_json(changed=self.has_changed(), **self.output)
@classmethod
def dependency(cls, name, msg):
cls._dependencies.append(DependencyCtxMgr(name, msg))
return cls._dependencies[-1]
def fail_on_missing_deps(self):
for d in self._dependencies:
if not d.has_it:
self.module.fail_json(changed=False,
exception="\n".join(traceback.format_exception(d.exc_type, d.exc_val, d.exc_tb)),
msg=d.text,
**self.output)
class StateMixin(object):
state_param = 'state'
default_state = None
def _state(self):
state = self.module.params.get(self.state_param)
return self.default_state if state is None else state
def _method(self, state):
return "{0}_{1}".format(self.state_param, state)
def __run__(self):
state = self._state()
self.vars.state = state
# resolve aliases
if state not in self.module.params:
aliased = [name for name, param in self.module.argument_spec.items() if state in param.get('aliases', [])]
if aliased:
state = aliased[0]
self.vars.effective_state = state
method = self._method(state)
if not hasattr(self, method):
return self.__state_fallback__()
func = getattr(self, method)
return func()
def __state_fallback__(self):
raise ValueError("Cannot find method: {0}".format(self._method(self._state())))
class CmdMixin(object):
"""
Mixin for mapping module options to running a CLI command with its arguments.
"""
command = None
command_args_formats = {}
run_command_fixed_options = {}
check_rc = False
force_lang = "C"
@property
def module_formats(self):
result = {}
for param in self.module.params.keys():
result[param] = ArgFormat(param)
return result
@property
def custom_formats(self):
result = {}
for param, fmt_spec in self.command_args_formats.items():
result[param] = ArgFormat(param, **fmt_spec)
return result
def _calculate_args(self, extra_params=None, params=None):
def add_arg_formatted_param(_cmd_args, arg_format, _value):
args = list(arg_format.to_text(_value))
return _cmd_args + args
def find_format(_param):
return self.custom_formats.get(_param, self.module_formats.get(_param))
extra_params = extra_params or dict()
cmd_args = list([self.command]) if isinstance(self.command, str) else list(self.command)
try:
cmd_args[0] = self.module.get_bin_path(cmd_args[0], required=True)
except ValueError:
pass
param_list = params if params else self.module.params.keys()
for param in param_list:
if isinstance(param, dict):
if len(param) != 1:
raise ModuleHelperException("run_command parameter as a dict must "
"contain only one key: {0}".format(param))
_param = list(param.keys())[0]
fmt = find_format(_param)
value = param[_param]
elif isinstance(param, str):
if param in self.module.argument_spec:
fmt = find_format(param)
value = self.module.params[param]
elif param in extra_params:
fmt = find_format(param)
value = extra_params[param]
else:
self.module.deprecate("Cannot determine value for parameter: {0}. "
"From version 4.0.0 onwards this will generate an exception".format(param),
version="4.0.0", collection_name="community.general")
continue
else:
raise ModuleHelperException("run_command parameter must be either a str or a dict: {0}".format(param))
cmd_args = add_arg_formatted_param(cmd_args, fmt, value)
return cmd_args
def process_command_output(self, rc, out, err):
return rc, out, err
def run_command(self, extra_params=None, params=None, *args, **kwargs):
self.vars.cmd_args = self._calculate_args(extra_params, params)
options = dict(self.run_command_fixed_options)
env_update = dict(options.get('environ_update', {}))
options['check_rc'] = options.get('check_rc', self.check_rc)
if self.force_lang:
env_update.update({'LANGUAGE': self.force_lang})
self.update_output(force_lang=self.force_lang)
options['environ_update'] = env_update
options.update(kwargs)
rc, out, err = self.module.run_command(self.vars.cmd_args, *args, **options)
self.update_output(rc=rc, stdout=out, stderr=err)
return self.process_command_output(rc, out, err)
class StateModuleHelper(StateMixin, ModuleHelper):
pass
class CmdModuleHelper(CmdMixin, ModuleHelper):
pass
class CmdStateModuleHelper(CmdMixin, StateMixin, ModuleHelper):
pass