This makes the module args parser more functional to eliminate side effects and eliminiates the 'return None' error path

to make sure we are handling more use cases.  Some paths are not yet complete, including most likely handling of the 'raw'
module.
pull/8958/merge
Michael DeHaan 10 years ago
parent 56b6cb5328
commit 79f41d9c1a

@ -13,20 +13,17 @@ class TestModArgsDwim(unittest.TestCase):
self.m = ModuleArgsParser()
pass
def _debug(self, mod, args, to):
print "RETURNED module = %s" % mod
print " args = %s" % args
print " to = %s" % to
def tearDown(self):
pass
def test_action_to_shell(self):
mod, args, to = self.m.parse(dict(action='shell echo hi'))
assert mod == 'command'
assert args == dict(
_raw_params = 'echo hi',
_uses_shell = True,
)
assert to is None
def test_basic_shell(self):
mod, args, to = self.m.parse(dict(shell='echo hi'))
self._debug(mod, args, to)
assert mod == 'command'
assert args == dict(
_raw_params = 'echo hi',
@ -36,6 +33,7 @@ class TestModArgsDwim(unittest.TestCase):
def test_basic_command(self):
mod, args, to = self.m.parse(dict(command='echo hi'))
self._debug(mod, args, to)
assert mod == 'command'
assert args == dict(
_raw_params = 'echo hi',
@ -44,6 +42,7 @@ class TestModArgsDwim(unittest.TestCase):
def test_shell_with_modifiers(self):
mod, args, to = self.m.parse(dict(shell='/bin/foo creates=/tmp/baz removes=/tmp/bleep'))
self._debug(mod, args, to)
assert mod == 'command'
assert args == dict(
creates = '/tmp/baz',
@ -55,30 +54,35 @@ class TestModArgsDwim(unittest.TestCase):
def test_normal_usage(self):
mod, args, to = self.m.parse(dict(copy='src=a dest=b'))
self._debug(mod, args, to)
assert mod == 'copy'
assert args == dict(src='a', dest='b')
assert to is None
def test_complex_args(self):
mod, args, to = self.m.parse(dict(copy=dict(src='a', dest='b')))
self._debug(mod, args, to)
assert mod == 'copy'
assert args == dict(src='a', dest='b')
assert to is None
def test_action_with_complex(self):
mod, args, to = self.m.parse(dict(action=dict(module='copy', src='a', dest='b')))
self._debug(mod, args, to)
assert mod == 'copy'
assert args == dict(src='a', dest='b')
assert to is None
def test_action_with_complex_and_complex_args(self):
mod, args, to = self.m.parse(dict(action=dict(module='copy', args=dict(src='a', dest='b'))))
self._debug(mod, args, to)
assert mod == 'copy'
assert args == dict(src='a', dest='b')
assert to is None
def test_local_action_string(self):
mod, args, to = self.m.parse(dict(local_action='copy src=a dest=b'))
self._debug(mod, args, to)
assert mod == 'copy'
assert args == dict(src='a', dest='b')
assert to is 'localhost'

@ -50,254 +50,192 @@ class ModuleArgsParser(object):
src: a
dest: b
This class exists so other things don't have to remember how this
all works. Pass it "part1" and "part2", and the parse function
will tell you about the modules in a predictable way.
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=None):
self._ds = None
self._task = task
def _get_delegate_to(self):
def _split_module_string(self, str):
'''
Returns the value of the delegate_to key from the task datastructure,
or None if the value was not directly specified
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.
'''
return self._ds.get('delegate_to', None)
def _get_old_style_action(self):
tokens = str.split()
if len(tokens) > 1:
return (tokens[0], " ".join(tokens[1:]))
else:
return (tokens[0], "")
def _handle_shell_weirdness(self, action, args):
'''
Searches the datastructure for 'action:' or 'local_action:' keywords.
When local_action is found, the delegate_to value is set to the localhost
IP, otherwise delegate_to is left as None.
Inputs:
- None
Outputs:
- None (if neither keyword is found), or a dictionary containing:
action:
the module name to be executed
args:
a dictionary containing the arguments to the module
delegate_to:
None or 'localhost'
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
'''
# determine if this is an 'action' or 'local_action'
if 'action' in self._ds:
action_data = self._ds.get('action', '')
delegate_to = None
elif 'local_action' in self._ds:
action_data = self._ds.get('local_action', '')
delegate_to = 'localhost'
else:
return None
# now we get the arguments for the module, which may be a
# string of key=value pairs, a dictionary of values, or a
# dictionary with a special 'args:' value in it
if isinstance(action_data, dict):
action = self._get_specified_module(action_data)
args = dict()
if 'args' in action_data:
args = self._get_args_from_ds(action, action_data)
del action_data['args']
other_args = action_data.copy()
# remove things we don't want in the args
if 'module' in other_args:
del other_args['module']
args.update(other_args)
elif isinstance(action_data, basestring):
action_data = action_data.strip()
if not action_data:
raise AnsibleError("when using 'action:' or 'local_action:', the module name must be specified", object=self._task)
else:
# split up the string based on spaces, where the first
# item specified must be a valid module name
parts = action_data.split(' ', 1)
action = parts[0]
if action not in module_finder:
raise AnsibleError("the module '%s' was not found in the list of loaded modules" % action, object=self._task)
if len(parts) > 1:
args = self._get_args_from_action(action, ' '.join(parts[1:]))
else:
args = {}
else:
raise AnsibleError('module args must be specified as a dictionary or string', object=self._task)
# 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)
new_args = {}
return dict(action=action, args=args, delegate_to=delegate_to)
# the shell module really is the command module with an additional
# parameter
if action == 'shell':
action = 'command'
new_args['_uses_shell'] = True
def _get_new_style_action(self):
# make sure the non-key-value params hop in the data
new_args['_raw_params'] = args['_raw_params']
return (action, new_args)
def _normalize_parameters(self, thing, action=None):
'''
Searches the datastructure for 'module_name:', where the module_name is a
valid module loaded by the module_finder plugin.
Inputs:
- None
Outputs:
- None (if no valid module is found), or a dictionary containing:
action:
the module name to be executed
args:
a dictionary containing the arguments to the module
delegate_to:
None
arguments can be fuzzy. Deal with all the forms.
'''
# for all keys in the datastructure, check to see if the value
# corresponds to a module found by the module_finder plugin
action = None
for item in self._ds:
if item in module_finder:
action = item
break
else:
# none of the keys matched a known module name
return None
# now we get the arguments for the module, which may be a
# string of key=value pairs, a dictionary of values, or a
# dictionary with a special 'args:' value in it
action_data = self._ds.get(action, '')
if isinstance(action_data, dict):
args = dict()
if 'args' in action_data:
args = self._get_args_from_ds(action, action_data)
del action_data['args']
other_args = action_data.copy()
# remove things we don't want in the args
if 'module' in other_args:
del other_args['module']
args.update(other_args)
args = dict()
# 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)
else:
args = self._get_args_from_action(action, action_data.strip())
(action, args) = self._normalize_new_style_args(thing)
# this can occasionally happen, simplify
if 'args' in args:
args = args['args']
return dict(action=action, args=args, delegate_to=None)
return (action, args)
def _get_args_from_ds(self, action, action_data):
def _normalize_old_style_args(self, thing):
'''
Gets the module arguments from the 'args' value of the
action_data, when action_data is a dict. The value of
'args' can be either a string or a dictionary itself, so
we use parse_kv() to split up the key=value pairs when
a string is found.
Inputs:
- action_data:
a dictionary of values, which may or may not contain a
key named 'args'
Outputs:
- a dictionary of values, representing the arguments to the
module action specified
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 }
'''
args = action_data.get('args', {}).copy()
if isinstance(args, basestring):
if action in ('command', 'shell'):
args = parse_kv(args, check_raw=True)
else:
args = parse_kv(args)
if isinstance(thing, dict):
# form is like: local_action: { module: 'xyz', x: 2, y: 3 } ... uncommon!
args = thing
elif isinstance(thing, basestring):
# form is like: local_action: copy src=a dest=b ... pretty common
args = parse_kv(thing)
else:
raise AnsibleParsingError("unexpected parameter type in action: %s" % type(thing), obj=self._task)
return args
def _get_args_from_action(self, action, action_data):
def _normalize_new_style_args(self, thing):
'''
Gets the module arguments from the action data when it is
specified as a string of key=value pairs. Special handling
is used for the command/shell modules, which allow free-
form syntax for the options.
Inputs:
- action:
the module to be executed
- action_data:
a string of key=value pairs (and possibly free-form arguments)
Outputs:
- A dictionary of values, representing the arguments to the
module action specified OR a string of key=value pairs (when
the module action is command or shell)
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'} )
'''
tokens = action_data.split()
if len(tokens) == 0:
return {}
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, basestring):
# form is like: copy: src=a dest=b ... common shorthand throughout ansible
(action, args) = self._split_module_string(thing)
args = parse_kv(args)
else:
joined = " ".join(tokens)
if action in ('command', 'shell'):
return parse_kv(joined, check_raw=True)
else:
return parse_kv(joined)
# need a dict or a string, so giving up
raise AnsibleParsingError("unexpected parameter type in action: %s" % type(thing), obj=self._task)
def _get_specified_module(self, action_data):
'''
gets the module if specified directly in the arguments, ie:
- action:
module: foo
Inputs:
- action_data:
a dictionary of values, which may or may not contain the
key 'module'
Outputs:
- a string representing the module specified in the data, or
None if that key was not found
'''
return action_data.get('module')
return (action, args)
def parse(self, ds):
'''
Given a task in one of the supported forms, parses and returns
returns the action, arguments, and delegate_to values for the
task.
Inputs:
- ds:
a dictionary datastructure representing the task as parsed
from a YAML file
Outputs:
- A tuple containing 3 values:
action:
the action (module name) to be executed
args:
the args for the action
delegate_to:
the delegate_to option (which may be None, if no delegate_to
option was specified and this is not a local_action)
task, dealing with all sorts of levels of fuzziness.
'''
assert type(ds) == dict
self._ds = ds
# first we try to get the module action/args based on the
# new-style format, where the module name is the key
result = self._get_new_style_action()
if result is None:
# failing that, we resort to checking for the old-style syntax,
# where 'action' or 'local_action' is the key
result = self._get_old_style_action()
if result is None:
raise AnsibleError('no action specified for this task', object=self._task)
# if the action is set to 'shell', we switch that to 'command' and
# set the special parameter '_uses_shell' to true in the args dict
if result['action'] == 'shell':
result['action'] = 'command'
result['args']['_uses_shell'] = True
# finally, we check to see if a delegate_to value was specified
# in the task datastructure (and raise an error for local_action,
# which essentially means we're delegating to localhost)
specified_delegate_to = self._get_delegate_to()
if specified_delegate_to is not None:
if result['delegate_to'] is not None:
raise AnsibleError('delegate_to cannot be used with local_action')
else:
result['delegate_to'] = specified_delegate_to
return (result['action'], result['args'], result['delegate_to'])
thing = None
action = None
delegate_to = None
args = dict()
if 'action' in ds:
# an old school 'action' statement
thing = ds['action']
delegate_to = None
action, args = self._normalize_parameters(thing)
elif 'local_action' in ds:
# local_action is similar but also implies a delegate_to
if action is not None:
raise AnsibleError("action and local_action are mutually exclusive")
thing = ds.get('local_action', '')
delegate_to = 'localhost'
action, args = self._normalize_parameters(thing)
else:
# module: <stuff> is the more new-style invocation
if action is not None:
raise AnsibleError("conflicting action statements")
# walk the input dictionary to see we recognize a module name
for (item, value) in ds.iteritems():
if item in module_finder:
# finding more than one module name is a problem
if action is not None:
raise AnsibleError("conflicting action statements")
action = item
thing = value
action, args = self._normalize_parameters(value, action=action)
# if we didn't see any module in the task at all, it's not a task really
if action is None:
raise AnsibleParserError("no action detected in task", obj=self._task)
# shell modules require special handling
(action, args) = self._handle_shell_weirdness(action, args)
return (action, args, delegate_to)

@ -239,4 +239,3 @@ def unquote(data):
if is_quoted(data):
return data[1:-1]
return data

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