ansible/lib/ansible/parsing/__init__.py
2015-05-03 21:47:26 -05:00

222 lines
7.8 KiB
Python

# (c) 2012-2014, 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
import json
import os
from yaml import load, YAMLError
from ansible.errors import AnsibleParserError
from ansible.errors.yaml_strings import YAML_SYNTAX_ERROR
from ansible.parsing.vault import VaultLib
from ansible.parsing.splitter import unquote
from ansible.parsing.yaml.loader import AnsibleLoader
from ansible.parsing.yaml.objects import AnsibleBaseYAMLObject, AnsibleUnicode
from ansible.utils.path import unfrackpath
class DataLoader():
'''
The DataLoader class is used to load and parse YAML or JSON content,
either from a given file name or from a string that was previously
read in through other means. A Vault password can be specified, and
any vault-encrypted files will be decrypted.
Data read from files will also be cached, so the file will never be
read from disk more than once.
Usage:
dl = DataLoader()
(or)
dl = DataLoader(vault_password='foo')
ds = dl.load('...')
ds = dl.load_from_file('/path/to/file')
'''
def __init__(self, vault_password=None):
self._basedir = '.'
self._vault_password = vault_password
self._FILE_CACHE = dict()
self._vault = VaultLib(password=vault_password)
def load(self, data, file_name='<string>', show_content=True):
'''
Creates a python datastructure from the given data, which can be either
a JSON or YAML string.
'''
try:
# we first try to load this data as JSON
return json.loads(data)
except:
# if loading JSON failed for any reason, we go ahead
# and try to parse it as YAML instead
if isinstance(data, AnsibleUnicode):
# The PyYAML's libyaml bindings use PyUnicode_CheckExact so
# they are unable to cope with our subclass.
# Unwrap and re-wrap the unicode so we can keep track of line
# numbers
new_data = unicode(data)
else:
new_data = data
try:
new_data = self._safe_load(new_data, file_name=file_name)
except YAMLError as yaml_exc:
self._handle_error(yaml_exc, file_name, show_content)
if isinstance(data, AnsibleUnicode):
new_data = AnsibleUnicode(new_data)
new_data.ansible_pos = data.ansible_pos
return new_data
def load_from_file(self, file_name):
''' Loads data from a file, which can contain either JSON or YAML. '''
file_name = self.path_dwim(file_name)
# if the file has already been read in and cached, we'll
# return those results to avoid more file/vault operations
if file_name in self._FILE_CACHE:
return self._FILE_CACHE[file_name]
# read the file contents and load the data structure from them
(file_data, show_content) = self._get_file_contents(file_name)
parsed_data = self.load(data=file_data, file_name=file_name, show_content=show_content)
# cache the file contents for next time
self._FILE_CACHE[file_name] = parsed_data
return parsed_data
def path_exists(self, path):
return os.path.exists(path)
def is_file(self, path):
return os.path.isfile(path)
def is_directory(self, path):
return os.path.isdir(path)
def list_directory(self, path):
return os.listdir(path)
def _safe_load(self, stream, file_name=None):
''' Implements yaml.safe_load(), except using our custom loader class. '''
loader = AnsibleLoader(stream, file_name)
try:
return loader.get_single_data()
finally:
loader.dispose()
def _get_file_contents(self, file_name):
'''
Reads the file contents from the given file name, and will decrypt them
if they are found to be vault-encrypted.
'''
if not self.path_exists(file_name) or not self.is_file(file_name):
raise AnsibleParserError("the file_name '%s' does not exist, or is not readable" % file_name)
show_content = True
try:
with open(file_name, 'r') as f:
data = f.read()
if self._vault.is_encrypted(data):
data = self._vault.decrypt(data)
show_content = False
return (data, show_content)
except (IOError, OSError) as e:
raise AnsibleParserError("an error occurred while trying to read the file '%s': %s" % (file_name, str(e)))
def _handle_error(self, yaml_exc, file_name, show_content):
'''
Optionally constructs an object (AnsibleBaseYAMLObject) to encapsulate the
file name/position where a YAML exception occurred, and raises an AnsibleParserError
to display the syntax exception information.
'''
# if the YAML exception contains a problem mark, use it to construct
# an object the error class can use to display the faulty line
err_obj = None
if hasattr(yaml_exc, 'problem_mark'):
err_obj = AnsibleBaseYAMLObject()
err_obj.ansible_pos = (file_name, yaml_exc.problem_mark.line + 1, yaml_exc.problem_mark.column + 1)
raise AnsibleParserError(YAML_SYNTAX_ERROR, obj=err_obj, show_content=show_content)
def get_basedir(self):
''' returns the current basedir '''
return self._basedir
def set_basedir(self, basedir):
''' sets the base directory, used to find files when a relative path is given '''
if basedir is not None:
self._basedir = basedir
def path_dwim(self, given):
'''
make relative paths work like folks expect.
'''
given = unquote(given)
if given.startswith("/"):
return os.path.abspath(given)
elif given.startswith("~"):
return os.path.abspath(os.path.expanduser(given))
else:
return os.path.abspath(os.path.join(self._basedir, given))
def path_dwim_relative(self, role_path, dirname, source):
''' find one file in a directory one level up in a dir named dirname relative to current '''
basedir = os.path.dirname(role_path)
if os.path.islink(basedir):
basedir = unfrackpath(basedir)
template2 = os.path.join(basedir, dirname, source)
else:
template2 = os.path.join(basedir, '..', dirname, source)
source1 = os.path.join(role_path, dirname, source)
if os.path.exists(source1):
return source1
cur_basedir = self._basedir
self.set_basedir(basedir)
source2 = self.path_dwim(template2)
if os.path.exists(source2):
self.set_basedir(cur_basedir)
return source2
obvious_local_path = self.path_dwim(source)
if os.path.exists(obvious_local_path):
self.set_basedir(cur_basedir)
return obvious_local_path
self.set_basedir(cur_basedir)
return source2 # which does not exist