/usr/lib/python3/dist-packages/cloudinit/templater.py is in cloud-init 0.7.9-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | # Copyright (C) 2012 Canonical Ltd.
# Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
# Copyright (C) 2012 Yahoo! Inc.
# Copyright (C) 2016 Amazon.com, Inc. or its affiliates.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Haefliger <juerg.haefliger@hp.com>
# Author: Joshua Harlow <harlowja@yahoo-inc.com>
# Author: Andrew Jorgensen <ajorgens@amazon.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
import collections
import re
try:
from Cheetah.Template import Template as CTemplate
CHEETAH_AVAILABLE = True
except (ImportError, AttributeError):
CHEETAH_AVAILABLE = False
try:
import jinja2
from jinja2 import Template as JTemplate
JINJA_AVAILABLE = True
except (ImportError, AttributeError):
JINJA_AVAILABLE = False
from cloudinit import log as logging
from cloudinit import type_utils as tu
from cloudinit import util
LOG = logging.getLogger(__name__)
TYPE_MATCHER = re.compile(r"##\s*template:(.*)", re.I)
BASIC_MATCHER = re.compile(r'\$\{([A-Za-z0-9_.]+)\}|\$([A-Za-z0-9_.]+)')
def basic_render(content, params):
"""This does simple replacement of bash variable like templates.
It identifies patterns like ${a} or $a and can also identify patterns like
${a.b} or $a.b which will look for a key 'b' in the dictionary rooted
by key 'a'.
"""
def replacer(match):
# Only 1 of the 2 groups will actually have a valid entry.
name = match.group(1)
if name is None:
name = match.group(2)
if name is None:
raise RuntimeError("Match encountered but no valid group present")
path = collections.deque(name.split("."))
selected_params = params
while len(path) > 1:
key = path.popleft()
if not isinstance(selected_params, dict):
raise TypeError("Can not traverse into"
" non-dictionary '%s' of type %s while"
" looking for subkey '%s'"
% (selected_params,
tu.obj_name(selected_params),
key))
selected_params = selected_params[key]
key = path.popleft()
if not isinstance(selected_params, dict):
raise TypeError("Can not extract key '%s' from non-dictionary"
" '%s' of type %s"
% (key, selected_params,
tu.obj_name(selected_params)))
return str(selected_params[key])
return BASIC_MATCHER.sub(replacer, content)
def detect_template(text):
def cheetah_render(content, params):
return CTemplate(content, searchList=[params]).respond()
def jinja_render(content, params):
# keep_trailing_newline is in jinja2 2.7+, not 2.6
add = "\n" if content.endswith("\n") else ""
return JTemplate(content,
undefined=jinja2.StrictUndefined,
trim_blocks=True).render(**params) + add
if text.find("\n") != -1:
ident, rest = text.split("\n", 1)
else:
ident = text
rest = ''
type_match = TYPE_MATCHER.match(ident)
if not type_match:
if CHEETAH_AVAILABLE:
LOG.debug("Using Cheetah as the renderer for unknown template.")
return ('cheetah', cheetah_render, text)
else:
return ('basic', basic_render, text)
else:
template_type = type_match.group(1).lower().strip()
if template_type not in ('jinja', 'cheetah', 'basic'):
raise ValueError("Unknown template rendering type '%s' requested"
% template_type)
if template_type == 'jinja' and not JINJA_AVAILABLE:
LOG.warn("Jinja not available as the selected renderer for"
" desired template, reverting to the basic renderer.")
return ('basic', basic_render, rest)
elif template_type == 'jinja' and JINJA_AVAILABLE:
return ('jinja', jinja_render, rest)
if template_type == 'cheetah' and not CHEETAH_AVAILABLE:
LOG.warn("Cheetah not available as the selected renderer for"
" desired template, reverting to the basic renderer.")
return ('basic', basic_render, rest)
elif template_type == 'cheetah' and CHEETAH_AVAILABLE:
return ('cheetah', cheetah_render, rest)
# Only thing left over is the basic renderer (it is always available).
return ('basic', basic_render, rest)
def render_from_file(fn, params):
if not params:
params = {}
template_type, renderer, content = detect_template(util.load_file(fn))
LOG.debug("Rendering content of '%s' using renderer %s", fn, template_type)
return renderer(content, params)
def render_to_file(fn, outfn, params, mode=0o644):
contents = render_from_file(fn, params)
util.write_file(outfn, contents, mode=mode)
def render_string_to_file(content, outfn, params, mode=0o644):
contents = render_string(content, params)
util.write_file(outfn, contents, mode=mode)
def render_string(content, params):
if not params:
params = {}
template_type, renderer, content = detect_template(content)
return renderer(content, params)
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