ansible/lib/ansible/template/vars.py

102 lines
3.6 KiB
Python

# (c) 2012, 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
from ansible.compat.six import iteritems
from jinja2.utils import missing
from ansible.utils.unicode import to_unicode
__all__ = ['AnsibleJ2Vars']
class AnsibleJ2Vars:
'''
Helper class to template all variable content before jinja2 sees it. This is
done by hijacking the variable storage that jinja2 uses, and overriding __contains__
and __getitem__ to look like a dict. Added bonus is avoiding duplicating the large
hashes that inject tends to be.
To facilitate using builtin jinja2 things like range, globals are also handled here.
'''
def __init__(self, templar, globals, locals=None, *extras):
'''
Initializes this object with a valid Templar() object, as
well as several dictionaries of variables representing
different scopes (in jinja2 terminology).
'''
self._templar = templar
self._globals = globals
self._extras = extras
self._locals = dict()
if isinstance(locals, dict):
for key, val in iteritems(locals):
if key[:2] == 'l_' and val is not missing:
self._locals[key[2:]] = val
def __contains__(self, k):
if k in self._templar._available_variables:
return True
if k in self._locals:
return True
for i in self._extras:
if k in i:
return True
if k in self._globals:
return True
return False
def __getitem__(self, varname):
if varname not in self._templar._available_variables:
if varname in self._locals:
return self._locals[varname]
for i in self._extras:
if varname in i:
return i[varname]
if varname in self._globals:
return self._globals[varname]
else:
raise KeyError("undefined variable: %s" % varname)
variable = self._templar._available_variables[varname]
# HostVars is special, return it as-is, as is the special variable
# 'vars', which contains the vars structure
from ansible.vars.hostvars import HostVars
if isinstance(variable, dict) and varname == "vars" or isinstance(variable, HostVars):
return variable
else:
value = None
try:
value = self._templar.template(variable)
except Exception as e:
raise type(e)(to_unicode(variable) + ': ' + e.message)
return value
def add_locals(self, locals):
'''
If locals are provided, create a copy of self containing those
locals in addition to what is already in this variable proxy.
'''
if locals is None:
return self
return AnsibleJ2Vars(self._templar, self._globals, locals=locals, *self._extras)