ansible/lib/ansible/template/native_helpers.py

65 lines
2.4 KiB
Python

# Copyright: (c) 2018, Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
from ast import literal_eval
from itertools import islice, chain
import types
from jinja2._compat import text_type
from jinja2.runtime import StrictUndefined
from ansible.parsing.yaml.objects import AnsibleVaultEncryptedUnicode
def ansible_native_concat(nodes):
"""Return a native Python type from the list of compiled nodes. If the
result is a single node, its value is returned. Otherwise, the nodes are
concatenated as strings. If the result can be parsed with
:func:`ast.literal_eval`, the parsed value is returned. Otherwise, the
string is returned.
"""
# https://github.com/pallets/jinja/blob/master/jinja2/nativetypes.py
head = list(islice(nodes, 2))
if not head:
return None
if len(head) == 1:
out = head[0]
# TODO send unvaulted data to literal_eval?
if isinstance(out, AnsibleVaultEncryptedUnicode):
return out.data
if isinstance(out, StrictUndefined):
# A hack to raise proper UndefinedError/AnsibleUndefinedVariable exception.
# We need to access the AnsibleUndefined(StrictUndefined) object by either of the following:
# __iter__, __str__, __len__, __nonzero__, __eq__, __ne__, __bool__, __hash__
# to actually raise the exception.
# (see Jinja2 source of StrictUndefined to get up to date info)
# Otherwise the undefined error would be raised on the next access which might not be properly handled.
# See https://github.com/ansible/ansible/issues/52158
# We do that only here because it is taken care of by text_type() in the else block below already.
str(out)
# short circuit literal_eval when possible
if not isinstance(out, list):
return out
else:
if isinstance(nodes, types.GeneratorType):
nodes = chain(head, nodes)
# Stringifying the nodes is important as it takes care of
# StrictUndefined by side-effect - by raising an exception.
out = u''.join([text_type(v) for v in nodes])
try:
return literal_eval(out)
except (ValueError, SyntaxError, MemoryError):
return out