class TaskExecutor:
'''
This is the main worker class for the executor pipeline, which
handles loading an action plugin to actually dispatch the task to
a given host. This class roughly corresponds to the old Runner()
class.
'''
# Modules that we optimize by squashing loop items into a single call to
# the module
SQUASH_ACTIONS = frozenset(C.DEFAULT_SQUASH_ACTIONS)
def __init__(self, host, task, job_vars, play_context, new_stdin, loader, shared_loader_obj):
self._host = host
self._task = task
self._job_vars = job_vars
self._play_context = play_context
self._new_stdin = new_stdin
self._loader = loader
self._shared_loader_obj = shared_loader_obj
try:
from __main__ import display
self._display = display
except ImportError:
from ansible.utils.display import Display
self._display = Display()
def run(self):
'''
The main executor entrypoint, where we determine if the specified
task requires looping and either runs the task with
'''
self._display.debug("in run()")
try:
# lookup plugins need to know if this task is executing from
# a role, so that it can properly find files/templates/etc.
roledir = None
if self._task._role:
roledir = self._task._role._role_path
self._job_vars['roledir'] = roledir
items = self._get_loop_items()
if items is not None:
if len(items) > 0:
item_results = self._run_loop(items)
# loop through the item results, and remember the changed/failed
# result flags based on any item there.
changed = False
failed = False
for item in item_results:
if 'changed' in item and item['changed']:
changed = True
if 'failed' in item and item['failed']:
failed = True
# create the overall result item, and set the changed/failed
# flags there to reflect the overall result of the loop
res = dict(results=item_results)
if changed:
res['changed'] = True
if failed:
res['failed'] = True
res['msg'] = 'One or more items failed'
else:
res['msg'] = 'All items completed'
else:
res = dict(changed=False, skipped=True, skipped_reason='No items in the list', results=[])
else:
self._display.debug("calling self._execute()")
res = self._execute()
self._display.debug("_execute() done")
# make sure changed is set in the result, if it's not present
if 'changed' not in res:
res['changed'] = False
def _clean_res(res):
if isinstance(res, dict):
for k in res.keys():
res[k] = _clean_res(res[k])
elif isinstance(res, list):
for idx,item in enumerate(res):
res[idx] = _clean_res(item)
elif isinstance(res, UnsafeProxy):
return res._obj
return res
self._display.debug("dumping result to json")
res = _clean_res(res)
self._display.debug("done dumping result, returning")
return res
except AnsibleError as e:
return dict(failed=True, msg=to_unicode(e, nonstring='simplerepr'))
finally:
try:
self._connection.close()
except AttributeError:
pass
except Exception as e:
self._display.debug("error closing connection: %s" % to_unicode(e))
def _get_loop_items(self):
'''
Loads a lookup plugin to handle the with_* portion of a task (if specified),
and returns the items result.
'''
# create a copy of the job vars here so that we can modify
# them temporarily without changing them too early for other
# parts of the code that might still need a pristine version
vars_copy = self._job_vars.copy()
# now we update them with the play context vars
self._play_context.update_vars(vars_copy)
templar = Templar(loader=self._loader, shared_loader_obj=self._shared_loader_obj, variables=vars_copy)
items = None
if self._task.loop:
if self._task.loop in self._shared_loader_obj.lookup_loader:
#TODO: remove convert_bare true and deprecate this in with_
try:
loop_terms = listify_lookup_plugin_terms(terms=self._task.loop_args, templar=templar, loader=self._loader, fail_on_undefined=True, convert_bare=True)
except AnsibleUndefinedVariable as e:
if 'has no attribute' in str(e):
loop_terms = []
self._display.deprecated("Skipping task due to undefined attribute, in the future this will be a fatal error.")
else:
raise
items = self._shared_loader_obj.lookup_loader.get(self._task.loop, loader=self._loader, templar=templar).run(terms=loop_terms, variables=vars_copy)
else:
raise AnsibleError("Unexpected failure in finding the lookup named '%s' in the available lookup plugins" % self._task.loop)
if items:
from ansible.vars.unsafe_proxy import UnsafeProxy
for idx, item in enumerate(items):
if item is not None and not isinstance(item, UnsafeProxy):
items[idx] = UnsafeProxy(item)
return items
def _run_loop(self, items):
'''
Runs the task with the loop items specified and collates the result
into an array named 'results' which is inserted into the final result
along with the item for which the loop ran.
'''
results = []
# make copies of the job vars and task so we can add the item to
# the variables and re-validate the task with the item variable
task_vars = self._job_vars.copy()
items = self._squash_items(items, task_vars)
for item in items:
task_vars['item'] = item
try:
tmp_task = self._task.copy()
tmp_play_context = self._play_context.copy()
except AnsibleParserError as e:
results.append(dict(failed=True, msg=str(e)))
continue
# now we swap the internal task and play context with their copies,
# execute, and swap them back so we can do the next iteration cleanly
(self._task, tmp_task) = (tmp_task, self._task)
(self._play_context, tmp_play_context) = (tmp_play_context, self._play_context)
res = self._execute(variables=task_vars)
(self._task, tmp_task) = (tmp_task, self._task)
(self._play_context, tmp_play_context) = (tmp_play_context, self._play_context)
# now update the result with the item info, and append the result
# to the list of results
res['item'] = item
results.append(res)
return results
def _squash_items(self, items, variables):
'''
Squash items down to a comma-separated list for certain modules which support it
(typically package management modules).
'''
if len(items) > 0 and self._task.action in self.SQUASH_ACTIONS:
final_items = []
name = self._task.args.pop('name', None) or self._task.args.pop('pkg', None)
for item in items:
variables['item'] = item
templar = Templar(loader=self._loader, shared_loader_obj=self._shared_loader_obj, variables=variables)
if self._task.evaluate_conditional(templar, variables):
if templar._contains_vars(name):
new_item = templar.template(name)
final_items.append(new_item)
else:
final_items.append(item)
joined_items = ",".join(final_items)
self._task.args['name'] = joined_items
return [joined_items]
else:
return items
def _execute(self, variables=None):
'''
The primary workhorse of the executor system, this runs the task
on the specified host (which may be the delegated_to host) and handles
the retry/until and block rescue/always execution
'''
if variables is None:
variables = self._job_vars
templar = Templar(loader=self._loader, shared_loader_obj=self._shared_loader_obj, variables=variables)
# apply the given task's information to the connection info,
# which may override some fields already set by the play or
# the options specified on the command line
self._play_context = self._play_context.set_task_and_variable_override(task=self._task, variables=variables, templar=templar)
# fields set from the play/task may be based on variables, so we have to
# do the same kind of post validation step on it here before we use it.
# We also add "magic" variables back into the variables dict to make sure
# a certain subset of variables exist.
self._play_context.update_vars(variables)
self._play_context.post_validate(templar=templar)
# Evaluate the conditional (if any) for this task, which we do before running
# the final task post-validation. We do this before the post validation due to
# the fact that the conditional may specify that the task be skipped due to a
# variable not being present which would otherwise cause validation to fail
if not self._task.evaluate_conditional(templar, variables):
self._display.debug("when evaulation failed, skipping this task")
return dict(changed=False, skipped=True, skip_reason='Conditional check failed', _ansible_no_log=self._play_context.no_log)
# Now we do final validation on the task, which sets all fields to their final values.
# In the case of debug tasks, we save any 'var' params and restore them after validating
# so that variables are not replaced too early.
prev_var = None
if self._task.action == 'debug' and 'var' in self._task.args:
prev_var = self._task.args.pop('var')
original_args = self._task.args.copy()
self._task.post_validate(templar=templar)
if '_variable_params' in self._task.args:
variable_params = self._task.args.pop('_variable_params')
if isinstance(variable_params, dict):
self._display.deprecated("Using variables for task params is unsafe, especially if the variables come from an external source like facts")
variable_params.update(self._task.args)
self._task.args = variable_params
if prev_var is not None:
self._task.args['var'] = prev_var
# if this task is a TaskInclude, we just return now with a success code so the
# main thread can expand the task list for the given host
if self._task.action == 'include':
include_variables = original_args
include_file = include_variables.get('_raw_params')
del include_variables['_raw_params']
return dict(include=include_file, include_variables=include_variables)
# get the connection and the handler for this execution
self._connection = self._get_connection(variables=variables, templar=templar)
self._connection.set_host_overrides(host=self._host)
self._handler = self._get_action_handler(connection=self._connection, templar=templar)
# And filter out any fields which were set to default(omit), and got the omit token value
omit_token = variables.get('omit')
if omit_token is not None:
self._task.args = dict((i[0], i[1]) for i in iteritems(self._task.args) if i[1] != omit_token)
# Read some values from the task, so that we can modify them if need be
retries = self._task.retries
if retries <= 0:
retries = 1
delay = self._task.delay
if delay < 0:
delay = 1
# make a copy of the job vars here, in case we need to update them
# with the registered variable value later on when testing conditions
vars_copy = variables.copy()
self._display.debug("starting attempt loop")
result = None
for attempt in range(retries):
if attempt > 0:
# FIXME: this should use the self._display.callback/message passing mechanism
self._display.display("FAILED - RETRYING: %s (%d retries left). Result was: %s" % (self._task, retries-attempt, result), color="red")
result['attempts'] = attempt + 1
self._display.debug("running the handler")
try:
result = self._handler.run(task_vars=variables)
except AnsibleConnectionFailure as e:
return dict(unreachable=True, msg=str(e))
self._display.debug("handler run complete")
if self._task.async > 0:
# the async_wrapper module returns dumped JSON via its stdout
# response, so we parse it here and replace the result
try:
result = json.loads(result.get('stdout'))
except (TypeError, ValueError) as e:
return dict(failed=True, msg="The async task did not return valid JSON: %s" % str(e))
if self._task.poll > 0:
result = self._poll_async_result(result=result, templar=templar)
# update the local copy of vars with the registered value, if specified,
# or any facts which may have been generated by the module execution
if self._task.register:
vars_copy[self._task.register] = result
if 'ansible_facts' in result:
vars_copy.update(result['ansible_facts'])
# create a conditional object to evaluate task conditions
cond = Conditional(loader=self._loader)
def _evaluate_changed_when_result(result):
if self._task.changed_when is not None:
cond.when = [ self._task.changed_when ]
result['changed'] = cond.evaluate_conditional(templar, vars_copy)
def _evaluate_failed_when_result(result):
if self._task.failed_when is not None:
cond.when = [ self._task.failed_when ]
failed_when_result = cond.evaluate_conditional(templar, vars_copy)
result['failed_when_result'] = result['failed'] = failed_when_result
return failed_when_result
return False
if self._task.until:
cond.when = self._task.until
if cond.evaluate_conditional(templar, vars_copy):
_evaluate_changed_when_result(result)
_evaluate_failed_when_result(result)
break
elif (self._task.changed_when is not None or self._task.failed_when is not None) and 'skipped' not in result:
_evaluate_changed_when_result(result)
if _evaluate_failed_when_result(result):
break
elif 'failed' not in result:
if result.get('rc', 0) != 0:
result['failed'] = True
else:
# if the result is not failed, stop trying
break
if attempt < retries - 1:
time.sleep(delay)
else:
_evaluate_changed_when_result(result)
_evaluate_failed_when_result(result)
# do the final update of the local variables here, for both registered
# values and any facts which may have been created
if self._task.register:
variables[self._task.register] = result
if 'ansible_facts' in result:
variables.update(result['ansible_facts'])
# save the notification target in the result, if it was specified, as
# this task may be running in a loop in which case the notification
# may be item-specific, ie. "notify: service {{item}}"
if self._task.notify is not None:
result['_ansible_notify'] = self._task.notify
# preserve no_log setting
result["_ansible_no_log"] = self._play_context.no_log
# and return
self._display.debug("attempt loop complete, returning result")
return result
class TaskExecutor:
'''
This is the main worker class for the executor pipeline, which
handles loading an action plugin to actually dispatch the task to
a given host. This class roughly corresponds to the old Runner()
class.
'''
# Modules that we optimize by squashing loop items into a single call to
# the module
SQUASH_ACTIONS = frozenset(C.DEFAULT_SQUASH_ACTIONS)
def __init__(self, host, task, job_vars, play_context, new_stdin, loader,
shared_loader_obj):
self._host = host
self._task = task
self._job_vars = job_vars
self._play_context = play_context
self._new_stdin = new_stdin
self._loader = loader
self._shared_loader_obj = shared_loader_obj
try:
from __main__ import display
self._display = display
except ImportError:
from ansible.utils.display import Display
self._display = Display()
def run(self):
'''
The main executor entrypoint, where we determine if the specified
task requires looping and either runs the task with
'''
self._display.debug("in run()")
try:
# lookup plugins need to know if this task is executing from
# a role, so that it can properly find files/templates/etc.
roledir = None
if self._task._role:
roledir = self._task._role._role_path
self._job_vars['roledir'] = roledir
items = self._get_loop_items()
if items is not None:
if len(items) > 0:
item_results = self._run_loop(items)
# loop through the item results, and remember the changed/failed
# result flags based on any item there.
changed = False
failed = False
for item in item_results:
if 'changed' in item and item['changed']:
changed = True
if 'failed' in item and item['failed']:
failed = True
# create the overall result item, and set the changed/failed
# flags there to reflect the overall result of the loop
res = dict(results=item_results)
if changed:
res['changed'] = True
if failed:
res['failed'] = True
res['msg'] = 'One or more items failed'
else:
res['msg'] = 'All items completed'
else:
res = dict(changed=False,
skipped=True,
skipped_reason='No items in the list',
results=[])
else:
self._display.debug("calling self._execute()")
res = self._execute()
self._display.debug("_execute() done")
# make sure changed is set in the result, if it's not present
if 'changed' not in res:
res['changed'] = False
def _clean_res(res):
if isinstance(res, dict):
for k in res.keys():
res[k] = _clean_res(res[k])
elif isinstance(res, list):
for idx, item in enumerate(res):
res[idx] = _clean_res(item)
elif isinstance(res, UnsafeProxy):
return res._obj
return res
self._display.debug("dumping result to json")
res = _clean_res(res)
self._display.debug("done dumping result, returning")
return res
except AnsibleError as e:
return dict(failed=True, msg=to_unicode(e, nonstring='simplerepr'))
finally:
try:
self._connection.close()
except AttributeError:
pass
except Exception as e:
self._display.debug("error closing connection: %s" %
to_unicode(e))
def _get_loop_items(self):
'''
Loads a lookup plugin to handle the with_* portion of a task (if specified),
and returns the items result.
'''
# create a copy of the job vars here so that we can modify
# them temporarily without changing them too early for other
# parts of the code that might still need a pristine version
vars_copy = self._job_vars.copy()
# now we update them with the play context vars
self._play_context.update_vars(vars_copy)
templar = Templar(loader=self._loader,
shared_loader_obj=self._shared_loader_obj,
variables=vars_copy)
items = None
if self._task.loop:
if self._task.loop in self._shared_loader_obj.lookup_loader:
#TODO: remove convert_bare true and deprecate this in with_
try:
loop_terms = listify_lookup_plugin_terms(
terms=self._task.loop_args,
templar=templar,
loader=self._loader,
fail_on_undefined=True,
convert_bare=True)
except AnsibleUndefinedVariable as e:
if 'has no attribute' in str(e):
loop_terms = []
self._display.deprecated(
"Skipping task due to undefined attribute, in the future this will be a fatal error."
)
else:
raise
items = self._shared_loader_obj.lookup_loader.get(
self._task.loop, loader=self._loader,
templar=templar).run(terms=loop_terms, variables=vars_copy)
else:
raise AnsibleError(
"Unexpected failure in finding the lookup named '%s' in the available lookup plugins"
% self._task.loop)
if items:
from ansible.vars.unsafe_proxy import UnsafeProxy
for idx, item in enumerate(items):
if item is not None and not isinstance(item, UnsafeProxy):
items[idx] = UnsafeProxy(item)
return items
def _run_loop(self, items):
'''
Runs the task with the loop items specified and collates the result
into an array named 'results' which is inserted into the final result
along with the item for which the loop ran.
'''
results = []
# make copies of the job vars and task so we can add the item to
# the variables and re-validate the task with the item variable
task_vars = self._job_vars.copy()
items = self._squash_items(items, task_vars)
for item in items:
task_vars['item'] = item
try:
tmp_task = self._task.copy()
tmp_play_context = self._play_context.copy()
except AnsibleParserError as e:
results.append(dict(failed=True, msg=str(e)))
continue
# now we swap the internal task and play context with their copies,
# execute, and swap them back so we can do the next iteration cleanly
(self._task, tmp_task) = (tmp_task, self._task)
(self._play_context, tmp_play_context) = (tmp_play_context,
self._play_context)
res = self._execute(variables=task_vars)
(self._task, tmp_task) = (tmp_task, self._task)
(self._play_context, tmp_play_context) = (tmp_play_context,
self._play_context)
# now update the result with the item info, and append the result
# to the list of results
res['item'] = item
results.append(res)
return results
def _squash_items(self, items, variables):
'''
Squash items down to a comma-separated list for certain modules which support it
(typically package management modules).
'''
if len(items) > 0 and self._task.action in self.SQUASH_ACTIONS:
final_items = []
name = self._task.args.pop('name', None) or self._task.args.pop(
'pkg', None)
for item in items:
variables['item'] = item
templar = Templar(loader=self._loader,
shared_loader_obj=self._shared_loader_obj,
variables=variables)
if self._task.evaluate_conditional(templar, variables):
if templar._contains_vars(name):
new_item = templar.template(name)
final_items.append(new_item)
else:
final_items.append(item)
joined_items = ",".join(final_items)
self._task.args['name'] = joined_items
return [joined_items]
else:
return items
def _execute(self, variables=None):
'''
The primary workhorse of the executor system, this runs the task
on the specified host (which may be the delegated_to host) and handles
the retry/until and block rescue/always execution
'''
if variables is None:
variables = self._job_vars
templar = Templar(loader=self._loader,
shared_loader_obj=self._shared_loader_obj,
variables=variables)
# apply the given task's information to the connection info,
# which may override some fields already set by the play or
# the options specified on the command line
self._play_context = self._play_context.set_task_and_variable_override(
task=self._task, variables=variables, templar=templar)
# fields set from the play/task may be based on variables, so we have to
# do the same kind of post validation step on it here before we use it.
# We also add "magic" variables back into the variables dict to make sure
# a certain subset of variables exist.
self._play_context.update_vars(variables)
self._play_context.post_validate(templar=templar)
# Evaluate the conditional (if any) for this task, which we do before running
# the final task post-validation. We do this before the post validation due to
# the fact that the conditional may specify that the task be skipped due to a
# variable not being present which would otherwise cause validation to fail
if not self._task.evaluate_conditional(templar, variables):
self._display.debug("when evaulation failed, skipping this task")
return dict(changed=False,
skipped=True,
skip_reason='Conditional check failed',
_ansible_no_log=self._play_context.no_log)
# Now we do final validation on the task, which sets all fields to their final values.
# In the case of debug tasks, we save any 'var' params and restore them after validating
# so that variables are not replaced too early.
prev_var = None
if self._task.action == 'debug' and 'var' in self._task.args:
prev_var = self._task.args.pop('var')
original_args = self._task.args.copy()
self._task.post_validate(templar=templar)
if '_variable_params' in self._task.args:
variable_params = self._task.args.pop('_variable_params')
if isinstance(variable_params, dict):
self._display.deprecated(
"Using variables for task params is unsafe, especially if the variables come from an external source like facts"
)
variable_params.update(self._task.args)
self._task.args = variable_params
if prev_var is not None:
self._task.args['var'] = prev_var
# if this task is a TaskInclude, we just return now with a success code so the
# main thread can expand the task list for the given host
if self._task.action == 'include':
include_variables = original_args
include_file = include_variables.get('_raw_params')
del include_variables['_raw_params']
return dict(include=include_file,
include_variables=include_variables)
# get the connection and the handler for this execution
self._connection = self._get_connection(variables=variables,
templar=templar)
self._connection.set_host_overrides(host=self._host)
self._handler = self._get_action_handler(connection=self._connection,
templar=templar)
# And filter out any fields which were set to default(omit), and got the omit token value
omit_token = variables.get('omit')
if omit_token is not None:
self._task.args = dict((i[0], i[1])
for i in iteritems(self._task.args)
if i[1] != omit_token)
# Read some values from the task, so that we can modify them if need be
retries = self._task.retries
if retries <= 0:
retries = 1
delay = self._task.delay
if delay < 0:
delay = 1
# make a copy of the job vars here, in case we need to update them
# with the registered variable value later on when testing conditions
vars_copy = variables.copy()
self._display.debug("starting attempt loop")
result = None
for attempt in range(retries):
if attempt > 0:
# FIXME: this should use the self._display.callback/message passing mechanism
self._display.display(
"FAILED - RETRYING: %s (%d retries left). Result was: %s" %
(self._task, retries - attempt, result),
color="red")
result['attempts'] = attempt + 1
self._display.debug("running the handler")
try:
result = self._handler.run(task_vars=variables)
except AnsibleConnectionFailure as e:
return dict(unreachable=True, msg=str(e))
self._display.debug("handler run complete")
if self._task. async > 0:
# the async_wrapper module returns dumped JSON via its stdout
# response, so we parse it here and replace the result
try:
result = json.loads(result.get('stdout'))
except (TypeError, ValueError) as e:
return dict(
failed=True,
msg="The async task did not return valid JSON: %s" %
str(e))
if self._task.poll > 0:
result = self._poll_async_result(result=result,
templar=templar)
# update the local copy of vars with the registered value, if specified,
# or any facts which may have been generated by the module execution
if self._task.register:
vars_copy[self._task.register] = result
if 'ansible_facts' in result:
vars_copy.update(result['ansible_facts'])
# create a conditional object to evaluate task conditions
cond = Conditional(loader=self._loader)
def _evaluate_changed_when_result(result):
if self._task.changed_when is not None:
cond.when = [self._task.changed_when]
result['changed'] = cond.evaluate_conditional(
templar, vars_copy)
def _evaluate_failed_when_result(result):
if self._task.failed_when is not None:
cond.when = [self._task.failed_when]
failed_when_result = cond.evaluate_conditional(
templar, vars_copy)
result['failed_when_result'] = result[
'failed'] = failed_when_result
return failed_when_result
return False
if self._task.until:
cond.when = self._task.until
if cond.evaluate_conditional(templar, vars_copy):
_evaluate_changed_when_result(result)
_evaluate_failed_when_result(result)
break
elif (self._task.changed_when is not None or self._task.failed_when
is not None) and 'skipped' not in result:
_evaluate_changed_when_result(result)
if _evaluate_failed_when_result(result):
break
elif 'failed' not in result:
if result.get('rc', 0) != 0:
result['failed'] = True
else:
# if the result is not failed, stop trying
break
if attempt < retries - 1:
time.sleep(delay)
else:
_evaluate_changed_when_result(result)
_evaluate_failed_when_result(result)
# do the final update of the local variables here, for both registered
# values and any facts which may have been created
if self._task.register:
variables[self._task.register] = result
if 'ansible_facts' in result:
variables.update(result['ansible_facts'])
# save the notification target in the result, if it was specified, as
# this task may be running in a loop in which case the notification
# may be item-specific, ie. "notify: service {{item}}"
if self._task.notify is not None:
result['_ansible_notify'] = self._task.notify
# preserve no_log setting
result["_ansible_no_log"] = self._play_context.no_log
# and return
self._display.debug("attempt loop complete, returning result")
return result
