# This file is part of cloud-init. See LICENSE file for license information.
from errno import EACCES
import os
import re
try:
from jinja2.exceptions import UndefinedError as JUndefinedError
except ImportError:
# No jinja2 dependency
JUndefinedError = Exception
from cloudinit import handlers
from cloudinit import log as logging
from cloudinit.sources import INSTANCE_JSON_FILE
from cloudinit.templater import render_string, MISSING_JINJA_PREFIX
from cloudinit.util import b64d, load_file, load_json, json_dumps
from cloudinit.settings import PER_ALWAYS
LOG = logging.getLogger(__name__)
class JinjaTemplatePartHandler(handlers.Handler):
prefixes = ['## template: jinja']
def __init__(self, paths, **_kwargs):
handlers.Handler.__init__(self, PER_ALWAYS, version=3)
self.paths = paths
self.sub_handlers = {}
for handler in _kwargs.get('sub_handlers', []):
for ctype in handler.list_types():
self.sub_handlers[ctype] = handler
def handle_part(self, data, ctype, filename, payload, frequency, headers):
if ctype in handlers.CONTENT_SIGNALS:
return
jinja_json_file = os.path.join(self.paths.run_dir, INSTANCE_JSON_FILE)
rendered_payload = render_jinja_payload_from_file(
payload, filename, jinja_json_file)
if not rendered_payload:
return
subtype = handlers.type_from_starts_with(rendered_payload)
sub_handler = self.sub_handlers.get(subtype)
if not sub_handler:
LOG.warning(
'Ignoring jinja template for %s. Could not find supported'
' sub-handler for type %s', filename, subtype)
return
if sub_handler.handler_version == 3:
sub_handler.handle_part(
data, ctype, filename, rendered_payload, frequency, headers)
elif sub_handler.handler_version == 2:
sub_handler.handle_part(
data, ctype, filename, rendered_payload, frequency)
def render_jinja_payload_from_file(
payload, payload_fn, instance_data_file, debug=False):
"""Render a jinja template payload sourcing variables from jinja_vars_path.
@param payload: String of jinja template content. Should begin with
## template: jinja\n.
@param payload_fn: String representing the filename from which the payload
was read used in error reporting. Generally in part-handling this is
'part-##'.
@param instance_data_file: A path to a json file containing variables that
will be used as jinja template variables.
@return: A string of jinja-rendered content with the jinja header removed.
Returns None on error.
"""
instance_data = {}
rendered_payload = None
if not os.path.exists(instance_data_file):
raise RuntimeError(
'Cannot render jinja template vars. Instance data not yet'
' present at %s' % instance_data_file)
try:
instance_data = load_json(load_file(instance_data_file))
except (IOError, OSError) as e:
if e.errno == EACCES:
raise RuntimeError(
'Cannot render jinja template vars. No read permission on'
" '%s'. Try sudo" % instance_data_file)
rendered_payload = render_jinja_payload(
payload, payload_fn, instance_data, debug)
if not rendered_payload:
return None
return rendered_payload
def render_jinja_payload(payload, payload_fn, instance_data, debug=False):
instance_jinja_vars = convert_jinja_instance_data(
instance_data,
decode_paths=instance_data.get('base64-encoded-keys', []))
if debug:
LOG.debug('Converted jinja variables\n%s',
json_dumps(instance_jinja_vars))
try:
rendered_payload = render_string(payload, instance_jinja_vars)
except (TypeError, JUndefinedError) as e:
LOG.warning(
'Ignoring jinja template for %s: %s', payload_fn, str(e))
return None
warnings = [
"'%s'" % var.replace(MISSING_JINJA_PREFIX, '')
for var in re.findall(
r'%s[^\s]+' % MISSING_JINJA_PREFIX, rendered_payload)]
if warnings:
LOG.warning(
"Could not render jinja template variables in file '%s': %s",
payload_fn, ', '.join(warnings))
return rendered_payload
def convert_jinja_instance_data(data, prefix='', sep='/', decode_paths=()):
"""Process instance-data.json dict for use in jinja templates.
Replace hyphens with underscores for jinja templates and decode any
base64_encoded_keys.
"""
result = {}
decode_paths = [path.replace('-', '_') for path in decode_paths]
for key, value in sorted(data.items()):
if '-' in key:
# Standardize keys for use in #cloud-config/shell templates
key = key.replace('-', '_')
key_path = '{0}{1}{2}'.format(prefix, sep, key) if prefix else key
if key_path in decode_paths:
value = b64d(value)
if isinstance(value, dict):
result[key] = convert_jinja_instance_data(
value, key_path, sep=sep, decode_paths=decode_paths)
if re.match(r'v\d+', key):
# Copy values to top-level aliases
for subkey, subvalue in result[key].items():
result[subkey] = subvalue
else:
result[key] = value
return result
# vi: ts=4 expandtab