module_helper.py Breakdown (#2393) (#2492)

* break down of module_helper into smaller pieces, keeping compatibility

* removed abc.ABC (py3 only) from code + fixed reference to vars.py

* multiple changes:

- mh.base - moved more functionalities to ModuleHelperBase
- mh.mixins.(cmd, state) - CmdMixin no longer inherits from ModuleHelperBase
- mh.mixins.deps - DependencyMixin now overrides run() method to test dependency
- mh.mixins.vars - created class VarsMixin
- mh.module_helper - moved functions to base class, added VarsMixin
- module_helper - importing AnsibleModule as well, for backward compatibility in test

* removed unnecessary __all__

* make pylint happy

* PR adjustments + bot config + changelog frag

* Update plugins/module_utils/mh/module_helper.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/module_utils/mh/module_helper.py

Co-authored-by: Felix Fontein <felix@fontein.de>

Co-authored-by: Felix Fontein <felix@fontein.de>
(cherry picked from commit d22dd5056e)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>

plugins/module_utils/mh/mixins/cmd.py

@@ -0,0 +1,167 @@
+# -*- 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
+
+
+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)]
+
+
+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 self.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 self.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)