path: root/lib/ansible/playbook/role/__init__.py

# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import os

from collections.abc import Container, Mapping, Set, Sequence

from ansible import constants as C
from ansible.errors import AnsibleError, AnsibleParserError, AnsibleAssertionError
from ansible.module_utils._text import to_text
from ansible.module_utils.six import binary_type, text_type
from ansible.playbook.attribute import FieldAttribute
from ansible.playbook.base import Base
from ansible.playbook.collectionsearch import CollectionSearch
from ansible.playbook.conditional import Conditional
from ansible.playbook.helpers import load_list_of_blocks
from ansible.playbook.role.metadata import RoleMetadata
from ansible.playbook.taggable import Taggable
from ansible.plugins.loader import add_all_plugin_dirs
from ansible.utils.collection_loader import AnsibleCollectionConfig
from ansible.utils.path import is_subpath
from ansible.utils.sentinel import Sentinel
from ansible.utils.vars import combine_vars

__all__ = ['Role', 'hash_params']

# TODO: this should be a utility function, but can't be a member of
#       the role due to the fact that it would require the use of self
#       in a static method. This is also used in the base class for
#       strategies (ansible/plugins/strategy/__init__.py)


def hash_params(params):
    """
    Construct a data structure of parameters that is hashable.

    This requires changing any mutable data structures into immutable ones.
    We chose a frozenset because role parameters have to be unique.

    .. warning::  this does not handle unhashable scalars.  Two things
        mitigate that limitation:

        1) There shouldn't be any unhashable scalars specified in the yaml
        2) Our only choice would be to return an error anyway.
    """
    # Any container is unhashable if it contains unhashable items (for
    # instance, tuple() is a Hashable subclass but if it contains a dict, it
    # cannot be hashed)
    if isinstance(params, Container) and not isinstance(params, (text_type, binary_type)):
        if isinstance(params, Mapping):
            try:
                # Optimistically hope the contents are all hashable
                new_params = frozenset(params.items())
            except TypeError:
                new_params = set()
                for k, v in params.items():
                    # Hash each entry individually
                    new_params.add((k, hash_params(v)))
                new_params = frozenset(new_params)

        elif isinstance(params, (Set, Sequence)):
            try:
                # Optimistically hope the contents are all hashable
                new_params = frozenset(params)
            except TypeError:
                new_params = set()
                for v in params:
                    # Hash each entry individually
                    new_params.add(hash_params(v))
                new_params = frozenset(new_params)
        else:
            # This is just a guess.
            new_params = frozenset(params)
        return new_params

    # Note: We do not handle unhashable scalars but our only choice would be
    # to raise an error there anyway.
    return frozenset((params,))


class Role(Base, Conditional, Taggable, CollectionSearch):

    delegate_to = FieldAttribute(isa='string')
    delegate_facts = FieldAttribute(isa='bool')

    def __init__(self, play=None, from_files=None, from_include=False, validate=True):
        self._role_name = None
        self._role_path = None
        self._role_collection = None
        self._role_params = dict()
        self._loader = None

        self._metadata = None
        self._play = play
        self._parents = []
        self._dependencies = []
        self._task_blocks = []
        self._handler_blocks = []
        self._compiled_handler_blocks = None
        self._default_vars = dict()
        self._role_vars = dict()
        self._had_task_run = dict()
        self._completed = dict()
        self._should_validate = validate

        if from_files is None:
            from_files = {}
        self._from_files = from_files

        # Indicates whether this role was included via include/import_role
        self.from_include = from_include

        super(Role, self).__init__()

    def __repr__(self):
        return self.get_name()

    def get_name(self, include_role_fqcn=True):
        if include_role_fqcn:
            return '.'.join(x for x in (self._role_collection, self._role_name) if x)
        return self._role_name

    @staticmethod
    def load(role_include, play, parent_role=None, from_files=None, from_include=False, validate=True):

        if from_files is None:
            from_files = {}
        try:
            # The ROLE_CACHE is a dictionary of role names, with each entry
            # containing another dictionary corresponding to a set of parameters
            # specified for a role as the key and the Role() object itself.
            # We use frozenset to make the dictionary hashable.

            params = role_include.get_role_params()
            if role_include.when is not None:
                params['when'] = role_include.when
            if role_include.tags is not None:
                params['tags'] = role_include.tags
            if from_files is not None:
                params['from_files'] = from_files
            if role_include.vars:
                params['vars'] = role_include.vars

            params['from_include'] = from_include

            hashed_params = hash_params(params)
            if role_include.get_name() in play.ROLE_CACHE:
                for (entry, role_obj) in play.ROLE_CACHE[role_include.get_name()].items():
                    if hashed_params == entry:
                        if parent_role:
                            role_obj.add_parent(parent_role)
                        return role_obj

            # TODO: need to fix cycle detection in role load (maybe use an empty dict
            #  for the in-flight in role cache as a sentinel that we're already trying to load
            #  that role?)
            # see https://github.com/ansible/ansible/issues/61527
            r = Role(play=play, from_files=from_files, from_include=from_include, validate=validate)
            r._load_role_data(role_include, parent_role=parent_role)

            if role_include.get_name() not in play.ROLE_CACHE:
                play.ROLE_CACHE[role_include.get_name()] = dict()

            # FIXME: how to handle cache keys for collection-based roles, since they're technically adjustable per task?
            play.ROLE_CACHE[role_include.get_name()][hashed_params] = r
            return r

        except RuntimeError:
            raise AnsibleError("A recursion loop was detected with the roles specified. Make sure child roles do not have dependencies on parent roles",
                               obj=role_include._ds)

    def _load_role_data(self, role_include, parent_role=None):
        self._role_name = role_include.role
        self._role_path = role_include.get_role_path()
        self._role_collection = role_include._role_collection
        self._role_params = role_include.get_role_params()
        self._variable_manager = role_include.get_variable_manager()
        self._loader = role_include.get_loader()

        if parent_role:
            self.add_parent(parent_role)

        # copy over all field attributes from the RoleInclude
        # update self._attr directly, to avoid squashing
        for attr_name in self.fattributes:
            setattr(self, f'_{attr_name}', getattr(role_include, f'_{attr_name}', Sentinel))

        # vars and default vars are regular dictionaries
        self._role_vars = self._load_role_yaml('vars', main=self._from_files.get('vars'), allow_dir=True)
        if self._role_vars is None:
            self._role_vars = {}
        elif not isinstance(self._role_vars, Mapping):
            raise AnsibleParserError("The vars/main.yml file for role '%s' must contain a dictionary of variables" % self._role_name)

        self._default_vars = self._load_role_yaml('defaults', main=self._from_files.get('defaults'), allow_dir=True)
        if self._default_vars is None:
            self._default_vars = {}
        elif not isinstance(self._default_vars, Mapping):
            raise AnsibleParserError("The defaults/main.yml file for role '%s' must contain a dictionary of variables" % self._role_name)

        # load the role's other files, if they exist
        metadata = self._load_role_yaml('meta')
        if metadata:
            self._metadata = RoleMetadata.load(metadata, owner=self, variable_manager=self._variable_manager, loader=self._loader)
            self._dependencies = self._load_dependencies()
        else:
            self._metadata = RoleMetadata()

        # reset collections list; roles do not inherit collections from parents, just use the defaults
        # FUTURE: use a private config default for this so we can allow it to be overridden later
        self.collections = []

        # configure plugin/collection loading; either prepend the current role's collection or configure legacy plugin loading
        # FIXME: need exception for explicit ansible.legacy?
        if self._role_collection:  # this is a collection-hosted role
            self.collections.insert(0, self._role_collection)
        else:  # this is a legacy role, but set the default collection if there is one
            default_collection = AnsibleCollectionConfig.default_collection
            if default_collection:
                self.collections.insert(0, default_collection)
            # legacy role, ensure all plugin dirs under the role are added to plugin search path
            add_all_plugin_dirs(self._role_path)

        # collections can be specified in metadata for legacy or collection-hosted roles
        if self._metadata.collections:
            self.collections.extend((c for c in self._metadata.collections if c not in self.collections))

        # if any collections were specified, ensure that core or legacy synthetic collections are always included
        if self.collections:
            # default append collection is core for collection-hosted roles, legacy for others
            default_append_collection = 'ansible.builtin' if self._role_collection else 'ansible.legacy'
            if 'ansible.builtin' not in self.collections and 'ansible.legacy' not in self.collections:
                self.collections.append(default_append_collection)

        task_data = self._load_role_yaml('tasks', main=self._from_files.get('tasks'))

        if self._should_validate:
            role_argspecs = self._get_role_argspecs()
            task_data = self._prepend_validation_task(task_data, role_argspecs)

        if task_data:
            try:
                self._task_blocks = load_list_of_blocks(task_data, play=self._play, role=self, loader=self._loader, variable_manager=self._variable_manager)
            except AssertionError as e:
                raise AnsibleParserError("The tasks/main.yml file for role '%s' must contain a list of tasks" % self._role_name,
                                         obj=task_data, orig_exc=e)

        handler_data = self._load_role_yaml('handlers', main=self._from_files.get('handlers'))
        if handler_data:
            try:
                self._handler_blocks = load_list_of_blocks(handler_data, play=self._play, role=self, use_handlers=True, loader=self._loader,
                                                           variable_manager=self._variable_manager)
            except AssertionError as e:
                raise AnsibleParserError("The handlers/main.yml file for role '%s' must contain a list of tasks" % self._role_name,
                                         obj=handler_data, orig_exc=e)

    def _get_role_argspecs(self):
        """Get the role argument spec data.

        Role arg specs can be in one of two files in the role meta subdir: argument_specs.yml
        or main.yml. The former has precedence over the latter. Data is not combined
        between the files.

        :returns: A dict of all data under the top-level ``argument_specs`` YAML key
            in the argument spec file. An empty dict is returned if there is no
            argspec data.
        """
        base_argspec_path = os.path.join(self._role_path, 'meta', 'argument_specs')

        for ext in C.YAML_FILENAME_EXTENSIONS:
            full_path = base_argspec_path + ext
            if self._loader.path_exists(full_path):
                # Note: _load_role_yaml() takes care of rebuilding the path.
                argument_specs = self._load_role_yaml('meta', main='argument_specs')
                try:
                    return argument_specs.get('argument_specs') or {}
                except AttributeError:
                    return {}

        # We did not find the meta/argument_specs.[yml|yaml] file, so use the spec
        # dict from the role meta data, if it exists. Ansible 2.11 and later will
        # have the 'argument_specs' attribute, but earlier versions will not.
        return getattr(self._metadata, 'argument_specs', {})

    def _prepend_validation_task(self, task_data, argspecs):
        '''Insert a role validation task if we have a role argument spec.

        This method will prepend a validation task to the front of the role task
        list to perform argument spec validation before any other tasks, if an arg spec
        exists for the entry point. Entry point defaults to `main`.

        :param task_data: List of tasks loaded from the role.
        :param argspecs: The role argument spec data dict.

        :returns: The (possibly modified) task list.
        '''
        if argspecs:
            # Determine the role entry point so we can retrieve the correct argument spec.
            # This comes from the `tasks_from` value to include_role or import_role.
            entrypoint = self._from_files.get('tasks', 'main')
            entrypoint_arg_spec = argspecs.get(entrypoint)

            if entrypoint_arg_spec:
                validation_task = self._create_validation_task(entrypoint_arg_spec, entrypoint)

                # Prepend our validate_argument_spec action to happen before any tasks provided by the role.
                # 'any tasks' can and does include 0 or None tasks, in which cases we create a list of tasks and add our
                # validate_argument_spec task
                if not task_data:
                    task_data = []
                task_data.insert(0, validation_task)
        return task_data

    def _create_validation_task(self, argument_spec, entrypoint_name):
        '''Create a new task data structure that uses the validate_argument_spec action plugin.

        :param argument_spec: The arg spec definition for a particular role entry point.
            This will be the entire arg spec for the entry point as read from the input file.
        :param entrypoint_name: The name of the role entry point associated with the
            supplied `argument_spec`.
        '''

        # If the arg spec provides a short description, use it to flesh out the validation task name
        task_name = "Validating arguments against arg spec '%s'" % entrypoint_name
        if 'short_description' in argument_spec:
            task_name = task_name + ' - ' + argument_spec['short_description']

        return {
            'action': {
                'module': 'ansible.builtin.validate_argument_spec',
                # Pass only the 'options' portion of the arg spec to the module.
                'argument_spec': argument_spec.get('options', {}),
                'provided_arguments': self._role_params,
                'validate_args_context': {
                    'type': 'role',
                    'name': self._role_name,
                    'argument_spec_name': entrypoint_name,
                    'path': self._role_path
                },
            },
            'name': task_name,
            'tags': ['always'],
        }

    def _load_role_yaml(self, subdir, main=None, allow_dir=False):
        '''
        Find and load role YAML files and return data found.
        :param subdir: subdir of role to search (vars, files, tasks, handlers, defaults)
        :type subdir: string
        :param main: filename to match, will default to 'main.<ext>' if not provided.
        :type main: string
        :param allow_dir: If true we combine results of multiple matching files found.
                          If false, highlander rules. Only for vars(dicts) and not tasks(lists).
        :type allow_dir: bool

        :returns: data from the matched file(s), type can be dict or list depending on vars or tasks.
        '''
        data = None
        file_path = os.path.join(self._role_path, subdir)
        if self._loader.path_exists(file_path) and self._loader.is_directory(file_path):
            # Valid extensions and ordering for roles is hard-coded to maintain portability
            extensions = ['.yml', '.yaml', '.json']  # same as default for YAML_FILENAME_EXTENSIONS

            # look for files w/o extensions before/after bare name depending on it being set or not
            # keep 'main' as original to figure out errors if no files found
            if main is None:
                _main = 'main'
                extensions.append('')
            else:
                _main = main
                extensions.insert(0, '')

            # not really 'find_vars_files' but find_files_with_extensions_default_to_yaml_filename_extensions
            found_files = self._loader.find_vars_files(file_path, _main, extensions, allow_dir)
            if found_files:
                for found in found_files:

                    if not is_subpath(found, file_path):
                        raise AnsibleParserError("Failed loading '%s' for role (%s) as it is not inside the expected role path: '%s'" %
                                                 (to_text(found), self._role_name, to_text(file_path)))

                    new_data = self._loader.load_from_file(found)
                    if new_data:
                        if data is not None and isinstance(new_data, Mapping):
                            data = combine_vars(data, new_data)
                        else:
                            data = new_data

                        # found data so no need to continue unless we want to merge
                        if not allow_dir:
                            break

            elif main is not None:
                # this won't trigger with default only when <subdir>_from is specified
                raise AnsibleParserError("Could not find specified file in role: %s/%s" % (subdir, main))

        return data

    def _load_dependencies(self):
        '''
        Recursively loads role dependencies from the metadata list of
        dependencies, if it exists
        '''

        deps = []
        if self._metadata:
            for role_include in self._metadata.dependencies:
                r = Role.load(role_include, play=self._play, parent_role=self)
                deps.append(r)

        return deps

    # other functions

    def add_parent(self, parent_role):
        ''' adds a role to the list of this roles parents '''
        if not isinstance(parent_role, Role):
            raise AnsibleAssertionError()

        if parent_role not in self._parents:
            self._parents.append(parent_role)

    def get_parents(self):
        return self._parents

    def get_default_vars(self, dep_chain=None):
        dep_chain = [] if dep_chain is None else dep_chain

        default_vars = dict()
        for dep in self.get_all_dependencies():
            default_vars = combine_vars(default_vars, dep.get_default_vars())
        if dep_chain:
            for parent in dep_chain:
                default_vars = combine_vars(default_vars, parent._default_vars)
        default_vars = combine_vars(default_vars, self._default_vars)
        return default_vars

    def get_inherited_vars(self, dep_chain=None):
        dep_chain = [] if dep_chain is None else dep_chain

        inherited_vars = dict()

        if dep_chain:
            for parent in dep_chain:
                inherited_vars = combine_vars(inherited_vars, parent.vars)
                inherited_vars = combine_vars(inherited_vars, parent._role_vars)
        return inherited_vars

    def get_role_params(self, dep_chain=None):
        dep_chain = [] if dep_chain is None else dep_chain

        params = {}
        if dep_chain:
            for parent in dep_chain:
                params = combine_vars(params, parent._role_params)
        params = combine_vars(params, self._role_params)
        return params

    def get_vars(self, dep_chain=None, include_params=True):
        dep_chain = [] if dep_chain is None else dep_chain

        all_vars = self.get_inherited_vars(dep_chain)

        for dep in self.get_all_dependencies():
            all_vars = combine_vars(all_vars, dep.get_vars(include_params=include_params))

        all_vars = combine_vars(all_vars, self.vars)
        all_vars = combine_vars(all_vars, self._role_vars)
        if include_params:
            all_vars = combine_vars(all_vars, self.get_role_params(dep_chain=dep_chain))

        return all_vars

    def get_direct_dependencies(self):
        return self._dependencies[:]

    def get_all_dependencies(self):
        '''
        Returns a list of all deps, built recursively from all child dependencies,
        in the proper order in which they should be executed or evaluated.
        '''

        child_deps = []

        for dep in self.get_direct_dependencies():
            for child_dep in dep.get_all_dependencies():
                child_deps.append(child_dep)
            child_deps.append(dep)

        return child_deps

    def get_task_blocks(self):
        return self._task_blocks[:]

    def get_handler_blocks(self, play, dep_chain=None):
        # Do not recreate this list each time ``get_handler_blocks`` is called.
        # Cache the results so that we don't potentially overwrite with copied duplicates
        #
        # ``get_handler_blocks`` may be called when handling ``import_role`` during parsing
        # as well as with ``Play.compile_roles_handlers`` from ``TaskExecutor``
        if self._compiled_handler_blocks:
            return self._compiled_handler_blocks

        self._compiled_handler_blocks = block_list = []

        # update the dependency chain here
        if dep_chain is None:
            dep_chain = []
        new_dep_chain = dep_chain + [self]

        for dep in self.get_direct_dependencies():
            dep_blocks = dep.get_handler_blocks(play=play, dep_chain=new_dep_chain)
            block_list.extend(dep_blocks)

        for task_block in self._handler_blocks:
            new_task_block = task_block.copy()
            new_task_block._dep_chain = new_dep_chain
            new_task_block._play = play
            block_list.append(new_task_block)

        return block_list

    def has_run(self, host):
        '''
        Returns true if this role has been iterated over completely and
        at least one task was run
        '''

        return host.name in self._completed and not self._metadata.allow_duplicates

    def compile(self, play, dep_chain=None):
        '''
        Returns the task list for this role, which is created by first
        recursively compiling the tasks for all direct dependencies, and
        then adding on the tasks for this role.

        The role compile() also remembers and saves the dependency chain
        with each task, so tasks know by which route they were found, and
        can correctly take their parent's tags/conditionals into account.
        '''
        from ansible.playbook.block import Block
        from ansible.playbook.task import Task

        block_list = []

        # update the dependency chain here
        if dep_chain is None:
            dep_chain = []
        new_dep_chain = dep_chain + [self]

        deps = self.get_direct_dependencies()
        for dep in deps:
            dep_blocks = dep.compile(play=play, dep_chain=new_dep_chain)
            block_list.extend(dep_blocks)

        for task_block in self._task_blocks:
            new_task_block = task_block.copy()
            new_task_block._dep_chain = new_dep_chain
            new_task_block._play = play
            block_list.append(new_task_block)

        eor_block = Block(play=play)
        eor_block._loader = self._loader
        eor_block._role = self
        eor_block._variable_manager = self._variable_manager
        eor_block.run_once = False

        eor_task = Task(block=eor_block)
        eor_task._role = self
        eor_task.action = 'meta'
        eor_task.args = {'_raw_params': 'role_complete'}
        eor_task.implicit = True
        eor_task.tags = ['always']
        eor_task.when = True

        eor_block.block = [eor_task]
        block_list.append(eor_block)

        return block_list

    def serialize(self, include_deps=True):
        res = super(Role, self).serialize()

        res['_role_name'] = self._role_name
        res['_role_path'] = self._role_path
        res['_role_vars'] = self._role_vars
        res['_role_params'] = self._role_params
        res['_default_vars'] = self._default_vars
        res['_had_task_run'] = self._had_task_run.copy()
        res['_completed'] = self._completed.copy()

        if self._metadata:
            res['_metadata'] = self._metadata.serialize()

        if include_deps:
            deps = []
            for role in self.get_direct_dependencies():
                deps.append(role.serialize())
            res['_dependencies'] = deps

        parents = []
        for parent in self._parents:
            parents.append(parent.serialize(include_deps=False))
        res['_parents'] = parents

        return res

    def deserialize(self, data, include_deps=True):
        self._role_name = data.get('_role_name', '')
        self._role_path = data.get('_role_path', '')
        self._role_vars = data.get('_role_vars', dict())
        self._role_params = data.get('_role_params', dict())
        self._default_vars = data.get('_default_vars', dict())
        self._had_task_run = data.get('_had_task_run', dict())
        self._completed = data.get('_completed', dict())

        if include_deps:
            deps = []
            for dep in data.get('_dependencies', []):
                r = Role()
                r.deserialize(dep)
                deps.append(r)
            setattr(self, '_dependencies', deps)

        parent_data = data.get('_parents', [])
        parents = []
        for parent in parent_data:
            r = Role()
            r.deserialize(parent, include_deps=False)
            parents.append(r)
        setattr(self, '_parents', parents)

        metadata_data = data.get('_metadata')
        if metadata_data:
            m = RoleMetadata()
            m.deserialize(metadata_data)
            self._metadata = m

        super(Role, self).deserialize(data)

    def set_loader(self, loader):
        self._loader = loader
        for parent in self._parents:
            parent.set_loader(loader)
        for dep in self.get_direct_dependencies():
            dep.set_loader(loader)