Adding upstream version 2.14.13.upstream/2.14.13

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 785 insertions, 0 deletions

diff --git a/lib/ansible/playbook/base.py b/lib/ansible/playbook/base.py
new file mode 100644
index 0000000..c772df1
--- /dev/null
+++ b/lib/ansible/playbook/base.py
@@ -0,0 +1,785 @@
+# Copyright: (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
+# Copyright: (c) 2017, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import itertools
+import operator
+import os
+
+from copy import copy as shallowcopy
+from functools import cache
+
+from jinja2.exceptions import UndefinedError
+
+from ansible import constants as C
+from ansible import context
+from ansible.errors import AnsibleError, AnsibleParserError, AnsibleUndefinedVariable, AnsibleAssertionError
+from ansible.module_utils.six import string_types
+from ansible.module_utils.parsing.convert_bool import boolean
+from ansible.module_utils._text import to_text, to_native
+from ansible.parsing.dataloader import DataLoader
+from ansible.playbook.attribute import Attribute, FieldAttribute, ConnectionFieldAttribute, NonInheritableFieldAttribute
+from ansible.plugins.loader import module_loader, action_loader
+from ansible.utils.collection_loader._collection_finder import _get_collection_metadata, AnsibleCollectionRef
+from ansible.utils.display import Display
+from ansible.utils.sentinel import Sentinel
+from ansible.utils.vars import combine_vars, isidentifier, get_unique_id
+
+display = Display()
+
+
+def _validate_action_group_metadata(action, found_group_metadata, fq_group_name):
+    valid_metadata = {
+        'extend_group': {
+            'types': (list, string_types,),
+            'errortype': 'list',
+        },
+    }
+
+    metadata_warnings = []
+
+    validate = C.VALIDATE_ACTION_GROUP_METADATA
+    metadata_only = isinstance(action, dict) and 'metadata' in action and len(action) == 1
+
+    if validate and not metadata_only:
+        found_keys = ', '.join(sorted(list(action)))
+        metadata_warnings.append("The only expected key is metadata, but got keys: {keys}".format(keys=found_keys))
+    elif validate:
+        if found_group_metadata:
+            metadata_warnings.append("The group contains multiple metadata entries.")
+        if not isinstance(action['metadata'], dict):
+            metadata_warnings.append("The metadata is not a dictionary. Got {metadata}".format(metadata=action['metadata']))
+        else:
+            unexpected_keys = set(action['metadata'].keys()) - set(valid_metadata.keys())
+            if unexpected_keys:
+                metadata_warnings.append("The metadata contains unexpected keys: {0}".format(', '.join(unexpected_keys)))
+            unexpected_types = []
+            for field, requirement in valid_metadata.items():
+                if field not in action['metadata']:
+                    continue
+                value = action['metadata'][field]
+                if not isinstance(value, requirement['types']):
+                    unexpected_types.append("%s is %s (expected type %s)" % (field, value, requirement['errortype']))
+            if unexpected_types:
+                metadata_warnings.append("The metadata contains unexpected key types: {0}".format(', '.join(unexpected_types)))
+    if metadata_warnings:
+        metadata_warnings.insert(0, "Invalid metadata was found for action_group {0} while loading module_defaults.".format(fq_group_name))
+        display.warning(" ".join(metadata_warnings))
+
+
+class _ClassProperty:
+    def __set_name__(self, owner, name):
+        self.name = name
+
+    def __get__(self, obj, objtype=None):
+        return getattr(objtype, f'_{self.name}')()
+
+
+class FieldAttributeBase:
+
+    fattributes = _ClassProperty()
+
+    @classmethod
+    @cache
+    def _fattributes(cls):
+        fattributes = {}
+        for class_obj in reversed(cls.__mro__):
+            for name, attr in list(class_obj.__dict__.items()):
+                if not isinstance(attr, Attribute):
+                    continue
+                fattributes[name] = attr
+                if attr.alias:
+                    setattr(class_obj, attr.alias, attr)
+                    fattributes[attr.alias] = attr
+        return fattributes
+
+    def __init__(self):
+
+        # initialize the data loader and variable manager, which will be provided
+        # later when the object is actually loaded
+        self._loader = None
+        self._variable_manager = None
+
+        # other internal params
+        self._validated = False
+        self._squashed = False
+        self._finalized = False
+
+        # every object gets a random uuid:
+        self._uuid = get_unique_id()
+
+        # init vars, avoid using defaults in field declaration as it lives across plays
+        self.vars = dict()
+
+    @property
+    def finalized(self):
+        return self._finalized
+
+    def dump_me(self, depth=0):
+        ''' this is never called from production code, it is here to be used when debugging as a 'complex print' '''
+        if depth == 0:
+            display.debug("DUMPING OBJECT ------------------------------------------------------")
+        display.debug("%s- %s (%s, id=%s)" % (" " * depth, self.__class__.__name__, self, id(self)))
+        if hasattr(self, '_parent') and self._parent:
+            self._parent.dump_me(depth + 2)
+            dep_chain = self._parent.get_dep_chain()
+            if dep_chain:
+                for dep in dep_chain:
+                    dep.dump_me(depth + 2)
+        if hasattr(self, '_play') and self._play:
+            self._play.dump_me(depth + 2)
+
+    def preprocess_data(self, ds):
+        ''' infrequently used method to do some pre-processing of legacy terms '''
+        return ds
+
+    def load_data(self, ds, variable_manager=None, loader=None):
+        ''' walk the input datastructure and assign any values '''
+
+        if ds is None:
+            raise AnsibleAssertionError('ds (%s) should not be None but it is.' % ds)
+
+        # cache the datastructure internally
+        setattr(self, '_ds', ds)
+
+        # the variable manager class is used to manage and merge variables
+        # down to a single dictionary for reference in templating, etc.
+        self._variable_manager = variable_manager
+
+        # the data loader class is used to parse data from strings and files
+        if loader is not None:
+            self._loader = loader
+        else:
+            self._loader = DataLoader()
+
+        # call the preprocess_data() function to massage the data into
+        # something we can more easily parse, and then call the validation
+        # function on it to ensure there are no incorrect key values
+        ds = self.preprocess_data(ds)
+        self._validate_attributes(ds)
+
+        # Walk all attributes in the class. We sort them based on their priority
+        # so that certain fields can be loaded before others, if they are dependent.
+        for name, attr in sorted(self.fattributes.items(), key=operator.itemgetter(1)):
+            # copy the value over unless a _load_field method is defined
+            if name in ds:
+                method = getattr(self, '_load_%s' % name, None)
+                if method:
+                    setattr(self, name, method(name, ds[name]))
+                else:
+                    setattr(self, name, ds[name])
+
+        # run early, non-critical validation
+        self.validate()
+
+        # return the constructed object
+        return self
+
+    def get_ds(self):
+        try:
+            return getattr(self, '_ds')
+        except AttributeError:
+            return None
+
+    def get_loader(self):
+        return self._loader
+
+    def get_variable_manager(self):
+        return self._variable_manager
+
+    def _post_validate_debugger(self, attr, value, templar):
+        value = templar.template(value)
+        valid_values = frozenset(('always', 'on_failed', 'on_unreachable', 'on_skipped', 'never'))
+        if value and isinstance(value, string_types) and value not in valid_values:
+            raise AnsibleParserError("'%s' is not a valid value for debugger. Must be one of %s" % (value, ', '.join(valid_values)), obj=self.get_ds())
+        return value
+
+    def _validate_attributes(self, ds):
+        '''
+        Ensures that there are no keys in the datastructure which do
+        not map to attributes for this object.
+        '''
+
+        valid_attrs = frozenset(self.fattributes)
+        for key in ds:
+            if key not in valid_attrs:
+                raise AnsibleParserError("'%s' is not a valid attribute for a %s" % (key, self.__class__.__name__), obj=ds)
+
+    def validate(self, all_vars=None):
+        ''' validation that is done at parse time, not load time '''
+        all_vars = {} if all_vars is None else all_vars
+
+        if not self._validated:
+            # walk all fields in the object
+            for (name, attribute) in self.fattributes.items():
+                # run validator only if present
+                method = getattr(self, '_validate_%s' % name, None)
+                if method:
+                    method(attribute, name, getattr(self, name))
+                else:
+                    # and make sure the attribute is of the type it should be
+                    value = getattr(self, f'_{name}', Sentinel)
+                    if value is not None:
+                        if attribute.isa == 'string' and isinstance(value, (list, dict)):
+                            raise AnsibleParserError(
+                                "The field '%s' is supposed to be a string type,"
+                                " however the incoming data structure is a %s" % (name, type(value)), obj=self.get_ds()
+                            )
+
+        self._validated = True
+
+    def _load_module_defaults(self, name, value):
+        if value is None:
+            return
+
+        if not isinstance(value, list):
+            value = [value]
+
+        validated_module_defaults = []
+        for defaults_dict in value:
+            if not isinstance(defaults_dict, dict):
+                raise AnsibleParserError(
+                    "The field 'module_defaults' is supposed to be a dictionary or list of dictionaries, "
+                    "the keys of which must be static action, module, or group names. Only the values may contain "
+                    "templates. For example: {'ping': \"{{ ping_defaults }}\"}"
+                )
+
+            validated_defaults_dict = {}
+            for defaults_entry, defaults in defaults_dict.items():
+                # module_defaults do not use the 'collections' keyword, so actions and
+                # action_groups that are not fully qualified are part of the 'ansible.legacy'
+                # collection. Update those entries here, so module_defaults contains
+                # fully qualified entries.
+                if defaults_entry.startswith('group/'):
+                    group_name = defaults_entry.split('group/')[-1]
+
+                    # The resolved action_groups cache is associated saved on the current Play
+                    if self.play is not None:
+                        group_name, dummy = self._resolve_group(group_name)
+
+                    defaults_entry = 'group/' + group_name
+                    validated_defaults_dict[defaults_entry] = defaults
+
+                else:
+                    if len(defaults_entry.split('.')) < 3:
+                        defaults_entry = 'ansible.legacy.' + defaults_entry
+
+                    resolved_action = self._resolve_action(defaults_entry)
+                    if resolved_action:
+                        validated_defaults_dict[resolved_action] = defaults
+
+                    # If the defaults_entry is an ansible.legacy plugin, these defaults
+                    # are inheritable by the 'ansible.builtin' subset, but are not
+                    # required to exist.
+                    if defaults_entry.startswith('ansible.legacy.'):
+                        resolved_action = self._resolve_action(
+                            defaults_entry.replace('ansible.legacy.', 'ansible.builtin.'),
+                            mandatory=False
+                        )
+                        if resolved_action:
+                            validated_defaults_dict[resolved_action] = defaults
+
+            validated_module_defaults.append(validated_defaults_dict)
+
+        return validated_module_defaults
+
+    @property
+    def play(self):
+        if hasattr(self, '_play'):
+            play = self._play
+        elif hasattr(self, '_parent') and hasattr(self._parent, '_play'):
+            play = self._parent._play
+        else:
+            play = self
+
+        if play.__class__.__name__ != 'Play':
+            # Should never happen, but handle gracefully by returning None, just in case
+            return None
+
+        return play
+
+    def _resolve_group(self, fq_group_name, mandatory=True):
+        if not AnsibleCollectionRef.is_valid_fqcr(fq_group_name):
+            collection_name = 'ansible.builtin'
+            fq_group_name = collection_name + '.' + fq_group_name
+        else:
+            collection_name = '.'.join(fq_group_name.split('.')[0:2])
+
+        # Check if the group has already been resolved and cached
+        if fq_group_name in self.play._group_actions:
+            return fq_group_name, self.play._group_actions[fq_group_name]
+
+        try:
+            action_groups = _get_collection_metadata(collection_name).get('action_groups', {})
+        except ValueError:
+            if not mandatory:
+                display.vvvvv("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
+                return fq_group_name, []
+
+            raise AnsibleParserError("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
+
+        # The collection may or may not use the fully qualified name
+        # Don't fail if the group doesn't exist in the collection
+        resource_name = fq_group_name.split(collection_name + '.')[-1]
+        action_group = action_groups.get(
+            fq_group_name,
+            action_groups.get(resource_name)
+        )
+        if action_group is None:
+            if not mandatory:
+                display.vvvvv("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
+                return fq_group_name, []
+            raise AnsibleParserError("Error loading module_defaults: could not resolve the module_defaults group %s" % fq_group_name)
+
+        resolved_actions = []
+        include_groups = []
+
+        found_group_metadata = False
+        for action in action_group:
+            # Everything should be a string except the metadata entry
+            if not isinstance(action, string_types):
+                _validate_action_group_metadata(action, found_group_metadata, fq_group_name)
+
+                if isinstance(action['metadata'], dict):
+                    found_group_metadata = True
+
+                    include_groups = action['metadata'].get('extend_group', [])
+                    if isinstance(include_groups, string_types):
+                        include_groups = [include_groups]
+                    if not isinstance(include_groups, list):
+                        # Bad entries may be a warning above, but prevent tracebacks by setting it back to the acceptable type.
+                        include_groups = []
+                continue
+
+            # The collection may or may not use the fully qualified name.
+            # If not, it's part of the current collection.
+            if not AnsibleCollectionRef.is_valid_fqcr(action):
+                action = collection_name + '.' + action
+            resolved_action = self._resolve_action(action, mandatory=False)
+            if resolved_action:
+                resolved_actions.append(resolved_action)
+
+        for action in resolved_actions:
+            if action not in self.play._action_groups:
+                self.play._action_groups[action] = []
+            self.play._action_groups[action].append(fq_group_name)
+
+        self.play._group_actions[fq_group_name] = resolved_actions
+
+        # Resolve extended groups last, after caching the group in case they recursively refer to each other
+        for include_group in include_groups:
+            if not AnsibleCollectionRef.is_valid_fqcr(include_group):
+                include_group = collection_name + '.' + include_group
+
+            dummy, group_actions = self._resolve_group(include_group, mandatory=False)
+
+            for action in group_actions:
+                if action not in self.play._action_groups:
+                    self.play._action_groups[action] = []
+                self.play._action_groups[action].append(fq_group_name)
+
+            self.play._group_actions[fq_group_name].extend(group_actions)
+            resolved_actions.extend(group_actions)
+
+        return fq_group_name, resolved_actions
+
+    def _resolve_action(self, action_name, mandatory=True):
+        context = module_loader.find_plugin_with_context(action_name)
+        if context.resolved and not context.action_plugin:
+            prefer = action_loader.find_plugin_with_context(action_name)
+            if prefer.resolved:
+                context = prefer
+        elif not context.resolved:
+            context = action_loader.find_plugin_with_context(action_name)
+
+        if context.resolved:
+            return context.resolved_fqcn
+        if mandatory:
+            raise AnsibleParserError("Could not resolve action %s in module_defaults" % action_name)
+        display.vvvvv("Could not resolve action %s in module_defaults" % action_name)
+
+    def squash(self):
+        '''
+        Evaluates all attributes and sets them to the evaluated version,
+        so that all future accesses of attributes do not need to evaluate
+        parent attributes.
+        '''
+        if not self._squashed:
+            for name in self.fattributes:
+                setattr(self, name, getattr(self, name))
+            self._squashed = True
+
+    def copy(self):
+        '''
+        Create a copy of this object and return it.
+        '''
+
+        try:
+            new_me = self.__class__()
+        except RuntimeError as e:
+            raise AnsibleError("Exceeded maximum object depth. This may have been caused by excessive role recursion", orig_exc=e)
+
+        for name in self.fattributes:
+            setattr(new_me, name, shallowcopy(getattr(self, f'_{name}', Sentinel)))
+
+        new_me._loader = self._loader
+        new_me._variable_manager = self._variable_manager
+        new_me._validated = self._validated
+        new_me._finalized = self._finalized
+        new_me._uuid = self._uuid
+
+        # if the ds value was set on the object, copy it to the new copy too
+        if hasattr(self, '_ds'):
+            new_me._ds = self._ds
+
+        return new_me
+
+    def get_validated_value(self, name, attribute, value, templar):
+        if attribute.isa == 'string':
+            value = to_text(value)
+        elif attribute.isa == 'int':
+            value = int(value)
+        elif attribute.isa == 'float':
+            value = float(value)
+        elif attribute.isa == 'bool':
+            value = boolean(value, strict=True)
+        elif attribute.isa == 'percent':
+            # special value, which may be an integer or float
+            # with an optional '%' at the end
+            if isinstance(value, string_types) and '%' in value:
+                value = value.replace('%', '')
+            value = float(value)
+        elif attribute.isa == 'list':
+            if value is None:
+                value = []
+            elif not isinstance(value, list):
+                value = [value]
+            if attribute.listof is not None:
+                for item in value:
+                    if not isinstance(item, attribute.listof):
+                        raise AnsibleParserError("the field '%s' should be a list of %s, "
+                                                 "but the item '%s' is a %s" % (name, attribute.listof, item, type(item)), obj=self.get_ds())
+                    elif attribute.required and attribute.listof == string_types:
+                        if item is None or item.strip() == "":
+                            raise AnsibleParserError("the field '%s' is required, and cannot have empty values" % (name,), obj=self.get_ds())
+        elif attribute.isa == 'set':
+            if value is None:
+                value = set()
+            elif not isinstance(value, (list, set)):
+                if isinstance(value, string_types):
+                    value = value.split(',')
+                else:
+                    # Making a list like this handles strings of
+                    # text and bytes properly
+                    value = [value]
+            if not isinstance(value, set):
+                value = set(value)
+        elif attribute.isa == 'dict':
+            if value is None:
+                value = dict()
+            elif not isinstance(value, dict):
+                raise TypeError("%s is not a dictionary" % value)
+        elif attribute.isa == 'class':
+            if not isinstance(value, attribute.class_type):
+                raise TypeError("%s is not a valid %s (got a %s instead)" % (name, attribute.class_type, type(value)))
+            value.post_validate(templar=templar)
+        return value
+
+    def set_to_context(self, name):
+        ''' set to parent inherited value or Sentinel as appropriate'''
+
+        attribute = self.fattributes[name]
+        if isinstance(attribute, NonInheritableFieldAttribute):
+            # setting to sentinel will trigger 'default/default()' on getter
+            setattr(self, name, Sentinel)
+        else:
+            try:
+                setattr(self, name, self._get_parent_attribute(name, omit=True))
+            except AttributeError:
+                # mostly playcontext as only tasks/handlers/blocks really resolve parent
+                setattr(self, name, Sentinel)
+
+    def post_validate(self, templar):
+        '''
+        we can't tell that everything is of the right type until we have
+        all the variables.  Run basic types (from isa) as well as
+        any _post_validate_<foo> functions.
+        '''
+
+        # save the omit value for later checking
+        omit_value = templar.available_variables.get('omit')
+
+        for (name, attribute) in self.fattributes.items():
+            if attribute.static:
+                value = getattr(self, name)
+
+                # we don't template 'vars' but allow template as values for later use
+                if name not in ('vars',) and templar.is_template(value):
+                    display.warning('"%s" is not templatable, but we found: %s, '
+                                    'it will not be templated and will be used "as is".' % (name, value))
+                continue
+
+            if getattr(self, name) is None:
+                if not attribute.required:
+                    continue
+                else:
+                    raise AnsibleParserError("the field '%s' is required but was not set" % name)
+            elif not attribute.always_post_validate and self.__class__.__name__ not in ('Task', 'Handler', 'PlayContext'):
+                # Intermediate objects like Play() won't have their fields validated by
+                # default, as their values are often inherited by other objects and validated
+                # later, so we don't want them to fail out early
+                continue
+
+            try:
+                # Run the post-validator if present. These methods are responsible for
+                # using the given templar to template the values, if required.
+                method = getattr(self, '_post_validate_%s' % name, None)
+                if method:
+                    value = method(attribute, getattr(self, name), templar)
+                elif attribute.isa == 'class':
+                    value = getattr(self, name)
+                else:
+                    # if the attribute contains a variable, template it now
+                    value = templar.template(getattr(self, name))
+
+                # If this evaluated to the omit value, set the value back to inherited by context
+                # or default specified in the FieldAttribute and move on
+                if omit_value is not None and value == omit_value:
+                    self.set_to_context(name)
+                    continue
+
+                # and make sure the attribute is of the type it should be
+                if value is not None:
+                    value = self.get_validated_value(name, attribute, value, templar)
+
+                # and assign the massaged value back to the attribute field
+                setattr(self, name, value)
+            except (TypeError, ValueError) as e:
+                value = getattr(self, name)
+                raise AnsibleParserError("the field '%s' has an invalid value (%s), and could not be converted to an %s."
+                                         "The error was: %s" % (name, value, attribute.isa, e), obj=self.get_ds(), orig_exc=e)
+            except (AnsibleUndefinedVariable, UndefinedError) as e:
+                if templar._fail_on_undefined_errors and name != 'name':
+                    if name == 'args':
+                        msg = "The task includes an option with an undefined variable. The error was: %s" % (to_native(e))
+                    else:
+                        msg = "The field '%s' has an invalid value, which includes an undefined variable. The error was: %s" % (name, to_native(e))
+                    raise AnsibleParserError(msg, obj=self.get_ds(), orig_exc=e)
+
+        self._finalized = True
+
+    def _load_vars(self, attr, ds):
+        '''
+        Vars in a play can be specified either as a dictionary directly, or
+        as a list of dictionaries. If the later, this method will turn the
+        list into a single dictionary.
+        '''
+
+        def _validate_variable_keys(ds):
+            for key in ds:
+                if not isidentifier(key):
+                    raise TypeError("'%s' is not a valid variable name" % key)
+
+        try:
+            if isinstance(ds, dict):
+                _validate_variable_keys(ds)
+                return combine_vars(self.vars, ds)
+            elif isinstance(ds, list):
+                all_vars = self.vars
+                for item in ds:
+                    if not isinstance(item, dict):
+                        raise ValueError
+                    _validate_variable_keys(item)
+                    all_vars = combine_vars(all_vars, item)
+                return all_vars
+            elif ds is None:
+                return {}
+            else:
+                raise ValueError
+        except ValueError as e:
+            raise AnsibleParserError("Vars in a %s must be specified as a dictionary, or a list of dictionaries" % self.__class__.__name__,
+                                     obj=ds, orig_exc=e)
+        except TypeError as e:
+            raise AnsibleParserError("Invalid variable name in vars specified for %s: %s" % (self.__class__.__name__, e), obj=ds, orig_exc=e)
+
+    def _extend_value(self, value, new_value, prepend=False):
+        '''
+        Will extend the value given with new_value (and will turn both
+        into lists if they are not so already). The values are run through
+        a set to remove duplicate values.
+        '''
+
+        if not isinstance(value, list):
+            value = [value]
+        if not isinstance(new_value, list):
+            new_value = [new_value]
+
+        # Due to where _extend_value may run for some attributes
+        # it is possible to end up with Sentinel in the list of values
+        # ensure we strip them
+        value = [v for v in value if v is not Sentinel]
+        new_value = [v for v in new_value if v is not Sentinel]
+
+        if prepend:
+            combined = new_value + value
+        else:
+            combined = value + new_value
+
+        return [i for i, _ in itertools.groupby(combined) if i is not None]
+
+    def dump_attrs(self):
+        '''
+        Dumps all attributes to a dictionary
+        '''
+        attrs = {}
+        for (name, attribute) in self.fattributes.items():
+            attr = getattr(self, name)
+            if attribute.isa == 'class' and hasattr(attr, 'serialize'):
+                attrs[name] = attr.serialize()
+            else:
+                attrs[name] = attr
+        return attrs
+
+    def from_attrs(self, attrs):
+        '''
+        Loads attributes from a dictionary
+        '''
+        for (attr, value) in attrs.items():
+            if attr in self.fattributes:
+                attribute = self.fattributes[attr]
+                if attribute.isa == 'class' and isinstance(value, dict):
+                    obj = attribute.class_type()
+                    obj.deserialize(value)
+                    setattr(self, attr, obj)
+                else:
+                    setattr(self, attr, value)
+
+        # from_attrs is only used to create a finalized task
+        # from attrs from the Worker/TaskExecutor
+        # Those attrs are finalized and squashed in the TE
+        # and controller side use needs to reflect that
+        self._finalized = True
+        self._squashed = True
+
+    def serialize(self):
+        '''
+        Serializes the object derived from the base object into
+        a dictionary of values. This only serializes the field
+        attributes for the object, so this may need to be overridden
+        for any classes which wish to add additional items not stored
+        as field attributes.
+        '''
+
+        repr = self.dump_attrs()
+
+        # serialize the uuid field
+        repr['uuid'] = self._uuid
+        repr['finalized'] = self._finalized
+        repr['squashed'] = self._squashed
+
+        return repr
+
+    def deserialize(self, data):
+        '''
+        Given a dictionary of values, load up the field attributes for
+        this object. As with serialize(), if there are any non-field
+        attribute data members, this method will need to be overridden
+        and extended.
+        '''
+
+        if not isinstance(data, dict):
+            raise AnsibleAssertionError('data (%s) should be a dict but is a %s' % (data, type(data)))
+
+        for (name, attribute) in self.fattributes.items():
+            if name in data:
+                setattr(self, name, data[name])
+            else:
+                self.set_to_context(name)
+
+        # restore the UUID field
+        setattr(self, '_uuid', data.get('uuid'))
+        self._finalized = data.get('finalized', False)
+        self._squashed = data.get('squashed', False)
+
+
+class Base(FieldAttributeBase):
+
+    name = NonInheritableFieldAttribute(isa='string', default='', always_post_validate=True)
+
+    # connection/transport
+    connection = ConnectionFieldAttribute(isa='string', default=context.cliargs_deferred_get('connection'))
+    port = FieldAttribute(isa='int')
+    remote_user = FieldAttribute(isa='string', default=context.cliargs_deferred_get('remote_user'))
+
+    # variables
+    vars = NonInheritableFieldAttribute(isa='dict', priority=100, static=True)
+
+    # module default params
+    module_defaults = FieldAttribute(isa='list', extend=True, prepend=True)
+
+    # flags and misc. settings
+    environment = FieldAttribute(isa='list', extend=True, prepend=True)
+    no_log = FieldAttribute(isa='bool')
+    run_once = FieldAttribute(isa='bool')
+    ignore_errors = FieldAttribute(isa='bool')
+    ignore_unreachable = FieldAttribute(isa='bool')
+    check_mode = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('check'))
+    diff = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('diff'))
+    any_errors_fatal = FieldAttribute(isa='bool', default=C.ANY_ERRORS_FATAL)
+    throttle = FieldAttribute(isa='int', default=0)
+    timeout = FieldAttribute(isa='int', default=C.TASK_TIMEOUT)
+
+    # explicitly invoke a debugger on tasks
+    debugger = FieldAttribute(isa='string')
+
+    # Privilege escalation
+    become = FieldAttribute(isa='bool', default=context.cliargs_deferred_get('become'))
+    become_method = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_method'))
+    become_user = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_user'))
+    become_flags = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_flags'))
+    become_exe = FieldAttribute(isa='string', default=context.cliargs_deferred_get('become_exe'))
+
+    # used to hold sudo/su stuff
+    DEPRECATED_ATTRIBUTES = []  # type: list[str]
+
+    def get_path(self):
+        ''' return the absolute path of the playbook object and its line number '''
+
+        path = ""
+        try:
+            path = "%s:%s" % (self._ds._data_source, self._ds._line_number)
+        except AttributeError:
+            try:
+                path = "%s:%s" % (self._parent._play._ds._data_source, self._parent._play._ds._line_number)
+            except AttributeError:
+                pass
+        return path
+
+    def get_dep_chain(self):
+
+        if hasattr(self, '_parent') and self._parent:
+            return self._parent.get_dep_chain()
+        else:
+            return None
+
+    def get_search_path(self):
+        '''
+        Return the list of paths you should search for files, in order.
+        This follows role/playbook dependency chain.
+        '''
+        path_stack = []
+
+        dep_chain = self.get_dep_chain()
+        # inside role: add the dependency chain from current to dependent
+        if dep_chain:
+            path_stack.extend(reversed([x._role_path for x in dep_chain if hasattr(x, '_role_path')]))
+
+        # add path of task itself, unless it is already in the list
+        task_dir = os.path.dirname(self.get_path())
+        if task_dir not in path_stack:
+            path_stack.append(task_dir)
+
+        return path_stack