ansible/lib/ansible/parsing/mod_args.py
James Cammarata 8716bf8021 All variables in complex args again
Also updates the CHANGELOG to note the slight change, where bare variables
in args are no longer allowed to be bare variables

Fixes #13518
2015-12-16 16:39:08 -05:00

313 lines
12 KiB
Python

# (c) 2014 Michael DeHaan, <michael@ansible.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
from ansible.compat.six import iteritems, string_types
from ansible.errors import AnsibleParserError,AnsibleError
from ansible.plugins import module_loader
from ansible.parsing.splitter import parse_kv, split_args
from ansible.template import Templar
# For filtering out modules correctly below
RAW_PARAM_MODULES = ([
'command',
'shell',
'script',
'include',
'include_vars',
'add_host',
'group_by',
'set_fact',
'raw',
'meta',
])
class ModuleArgsParser:
"""
There are several ways a module and argument set can be expressed:
# legacy form (for a shell command)
- action: shell echo hi
# common shorthand for local actions vs delegate_to
- local_action: shell echo hi
# most commonly:
- copy: src=a dest=b
# legacy form
- action: copy src=a dest=b
# complex args form, for passing structured data
- copy:
src: a
dest: b
# gross, but technically legal
- action:
module: copy
args:
src: a
dest: b
# extra gross, but also legal. in this case, the args specified
# will act as 'defaults' and will be overridden by any args specified
# in one of the other formats (complex args under the action, or
# parsed from the k=v string
- command: 'pwd'
args:
chdir: '/tmp'
This class has some of the logic to canonicalize these into the form
- module: <module_name>
delegate_to: <optional>
args: <args>
Args may also be munged for certain shell command parameters.
"""
def __init__(self, task_ds=dict()):
assert isinstance(task_ds, dict)
self._task_ds = task_ds
def _split_module_string(self, module_string):
'''
when module names are expressed like:
action: copy src=a dest=b
the first part of the string is the name of the module
and the rest are strings pertaining to the arguments.
'''
tokens = split_args(module_string)
if len(tokens) > 1:
return (tokens[0], " ".join(tokens[1:]))
else:
return (tokens[0], "")
def _handle_shell_weirdness(self, action, args):
'''
given an action name and an args dictionary, return the
proper action name and args dictionary. This mostly is due
to shell/command being treated special and nothing else
'''
# don't handle non shell/command modules in this function
# TODO: in terms of the whole app, should 'raw' also fit here?
if action not in ['shell', 'command']:
return (action, args)
# the shell module really is the command module with an additional
# parameter
if action == 'shell':
action = 'command'
args['_uses_shell'] = True
return (action, args)
def _normalize_parameters(self, thing, action=None, additional_args=dict()):
'''
arguments can be fuzzy. Deal with all the forms.
'''
# final args are the ones we'll eventually return, so first update
# them with any additional args specified, which have lower priority
# than those which may be parsed/normalized next
final_args = dict()
if additional_args:
if isinstance(additional_args, string_types):
templar = Templar(loader=None)
if templar._contains_vars(additional_args):
final_args['_variable_params'] = additional_args
else:
raise AnsibleParserError("Complex args containing variables cannot use bare variables, and must use the full variable style ('{{var_name}}')")
elif isinstance(additional_args, dict):
final_args.update(additional_args)
else:
raise AnsibleParserError('Complex args must be a dictionary or variable string ("{{var}}").')
# how we normalize depends if we figured out what the module name is
# yet. If we have already figured it out, it's an 'old style' invocation.
# otherwise, it's not
if action is not None:
args = self._normalize_old_style_args(thing, action)
else:
(action, args) = self._normalize_new_style_args(thing)
# this can occasionally happen, simplify
if args and 'args' in args:
tmp_args = args.pop('args')
if isinstance(tmp_args, string_types):
tmp_args = parse_kv(tmp_args)
args.update(tmp_args)
# only internal variables can start with an underscore, so
# we don't allow users to set them directy in arguments
if args and action not in ('command', 'shell', 'script', 'raw'):
for arg in args:
if arg.startswith('_ansible_'):
raise AnsibleError("invalid parameter specified for action '%s': '%s'" % (action, arg))
# finally, update the args we're going to return with the ones
# which were normalized above
if args:
final_args.update(args)
return (action, final_args)
def _normalize_old_style_args(self, thing, action):
'''
deals with fuzziness in old-style (action/local_action) module invocations
returns tuple of (module_name, dictionary_args)
possible example inputs:
{ 'local_action' : 'shell echo hi' }
{ 'action' : 'shell echo hi' }
{ 'local_action' : { 'module' : 'ec2', 'x' : 1, 'y': 2 }}
standardized outputs like:
( 'command', { _raw_params: 'echo hi', _uses_shell: True }
'''
if isinstance(thing, dict):
# form is like: local_action: { module: 'xyz', x: 2, y: 3 } ... uncommon!
args = thing
elif isinstance(thing, string_types):
# form is like: local_action: copy src=a dest=b ... pretty common
check_raw = action in ('command', 'shell', 'script', 'raw')
args = parse_kv(thing, check_raw=check_raw)
elif thing is None:
# this can happen with modules which take no params, like ping:
args = None
else:
raise AnsibleParserError("unexpected parameter type in action: %s" % type(thing), obj=self._task_ds)
return args
def _normalize_new_style_args(self, thing):
'''
deals with fuzziness in new style module invocations
accepting key=value pairs and dictionaries, and always returning dictionaries
returns tuple of (module_name, dictionary_args)
possible example inputs:
{ 'shell' : 'echo hi' }
{ 'ec2' : { 'region' : 'xyz' }
{ 'ec2' : 'region=xyz' }
standardized outputs like:
('ec2', { region: 'xyz'} )
'''
action = None
args = None
if isinstance(thing, dict):
# form is like: copy: { src: 'a', dest: 'b' } ... common for structured (aka "complex") args
thing = thing.copy()
if 'module' in thing:
action = thing['module']
args = thing.copy()
del args['module']
elif isinstance(thing, string_types):
# form is like: copy: src=a dest=b ... common shorthand throughout ansible
(action, args) = self._split_module_string(thing)
check_raw = action in ('command', 'shell', 'script', 'raw')
args = parse_kv(args, check_raw=check_raw)
else:
# need a dict or a string, so giving up
raise AnsibleParserError("unexpected parameter type in action: %s" % type(thing), obj=self._task_ds)
return (action, args)
def parse(self):
'''
Given a task in one of the supported forms, parses and returns
returns the action, arguments, and delegate_to values for the
task, dealing with all sorts of levels of fuzziness.
'''
thing = None
action = None
delegate_to = self._task_ds.get('delegate_to', None)
args = dict()
# this is the 'extra gross' scenario detailed above, so we grab
# the args and pass them in as additional arguments, which can/will
# be overwritten via dict updates from the other arg sources below
additional_args = self._task_ds.get('args', dict())
# We can have one of action, local_action, or module specified
# action
if 'action' in self._task_ds:
# an old school 'action' statement
thing = self._task_ds['action']
action, args = self._normalize_parameters(thing, additional_args=additional_args)
# local_action
if 'local_action' in self._task_ds:
# local_action is similar but also implies a delegate_to
if action is not None:
raise AnsibleParserError("action and local_action are mutually exclusive", obj=self._task_ds)
thing = self._task_ds.get('local_action', '')
delegate_to = 'localhost'
action, args = self._normalize_parameters(thing, additional_args=additional_args)
# module: <stuff> is the more new-style invocation
# walk the input dictionary to see we recognize a module name
for (item, value) in iteritems(self._task_ds):
if item in module_loader or item == 'meta' or item == 'include':
# finding more than one module name is a problem
if action is not None:
raise AnsibleParserError("conflicting action statements", obj=self._task_ds)
action = item
thing = value
action, args = self._normalize_parameters(value, action=action, additional_args=additional_args)
# if we didn't see any module in the task at all, it's not a task really
if action is None:
if 'ping' not in module_loader:
raise AnsibleParserError("The requested action was not found in configured module paths. "
"Additionally, core modules are missing. If this is a checkout, "
"run 'git submodule update --init --recursive' to correct this problem.",
obj=self._task_ds)
else:
raise AnsibleParserError("no action detected in task", obj=self._task_ds)
elif args.get('_raw_params', '') != '' and action not in RAW_PARAM_MODULES:
templar = Templar(loader=None)
raw_params = args.pop('_raw_params')
if templar._contains_vars(raw_params):
args['_variable_params'] = raw_params
else:
raise AnsibleParserError("this task '%s' has extra params, which is only allowed in the following modules: %s" % (action, ", ".join(RAW_PARAM_MODULES)), obj=self._task_ds)
# shell modules require special handling
(action, args) = self._handle_shell_weirdness(action, args)
return (action, args, delegate_to)